第 177 期·中文精讀

里斯託·米庫萊寧:神經進化與進化計算

Risto Miikkulainen: Neuroevolution and Evolutionary Computation

電腦科學家講解如何用進化演算法最佳化神經網路結構,及其在遊戲、機器人控制與開放式創新中的應用。

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中文精讀由 AI 基於原始訪談改寫,非官方翻譯,可能存在偏差或錯誤;表述以原音訊與官方文稿為準。說明

如果把地球這個實驗重跑一百萬次,人類還會出現嗎?

這個問題扔給生物學家,基本沒法回答,樣本只有一個,沒法做對照。但扔給里斯託·米庫萊寧(Risto Miikkulainen)就變得可操作了。他在德州大學奧斯汀分校做電腦科學,同時在 Cognizant 擔任進化人工智慧的副總裁,一輩子在乾的事就是把這些過程寫成程式碼,然後跑起來。

他的答案分兩層。第一層很確定:有些東西會反覆出現。對物體的操控、對生拇指、某種溝通方式、某種決策機制,還有視覺。眼睛在生物史上獨立演化過很多次,不同的視覺系統各自成型,做法不一樣,但都能把活幹成。這些是進化在給定物理世界後幾乎必然會撞上的解。

第二層就不確定了:會不會出現靈長類,會不會出現人,會不會出現一個能改造環境的物種?米庫萊寧說,工具使用和環境建造這兩件事大機率會重演,因為一旦有 agent 能操控外部世界,它的生存優勢就是壓倒性的。至於那個物種長什麼樣,跑一百萬次可能得到一百萬種答案。

我們大致知道我們想要什麼:會溝通、會合作、會操控物體的智慧體。所以我們會針對這些過程去構建檢測器和視覺化工具。(米庫萊寧)

怎麼在一鍋湯裡認出"人"

這裡有個實際問題。假設你真的在跑這個模擬,幾百萬個 agent 在螢幕裡亂竄,你怎麼知道哪個是"人"?

米庫萊寧的做法是先定義觀測指標。他想看的第一個訊號是對環境的改造程度。城市是最直接的證據:絕大多數人住在人造環境裡。這不叫生活在環境裡,這叫按自己的偏好重建環境。白蟻能堆出幾米高的丘,鳥能築巢,但沒有任何非人生物造出過城市這種複雜度的東西。

反過來說,你也可以用另一套指標得出相反結論。鯊魚活了四億年,比樹還早,經歷了多次大滅絕還在。人類才來了多久,已經開始把環境往死裡搞。按"長期穩定存活"這個指標打分,鯊魚比人類聰明得多。

所以"檢測智慧"這件事本身就帶著觀測者的偏見。米庫萊寧承認這一點,但他不覺得這是個死結:跑得次數夠多,檢測器也可以在跑的過程中被修正。

生命的第零步,以及大腦那次失控

從原始湯裡冒出第一個能自我複製的分子,這一步有多難?

米庫萊寧說,有一批人正在死磕這個問題,而且已經很接近了。給一點人工輔助,調好條件,讓自複製發生是可以做到的。進化花了幾十億年才走出這一步,我們大概用不了那麼久,因為我們已經知道終點長什麼樣。

真正讓他覺得有意思的是後面那一段:大腦的失控式進化。前面幾十億年慢得像爬,然後突然在很短的時間裡炸出了高等動物和人類。這個加速是怎麼發生的,條件是什麼,能不能復現,他也沒有答案。

進化真正迷人的地方是,最終大腦出現了失控式進化,造出了人類,也造出了其他高等動物。這件事發生得非常快。這是個大問題:它可複製嗎?如果發生了,它會不會走向同一個方向?(米庫萊寧)

多細胞生物、原始湯、前幾步,用計算模型搭出來還有希望。但要讓一個系統自己跑到"長出大腦"這一步,條件是什麼,沒人知道。這也是為什麼進化計算這個領域搞了五十年,還沒有造出過一次生物學意義上的"重大轉變"。

智慧的第一層與第二層定義

米庫萊寧對"什麼是智慧"的處理方式很工程師:不去定義它,去造它。

第一層定義樸素得幾乎不像是定義:一個有受限的感知能力和行動能力的程式,在世界裡活動,並且有一套做決策的機制。目標是活下去。繁衍也算,解決你給它的任務也算。按這個標準,很多動物都算智慧,甚至一些不那麼像動物的東西也能算。核心就一句:智慧是在給定資源下活下去的技能。

第二層定義他更喜歡,也更人性化:你留下的東西,比你自己的存在更多。你做出來的東西對別人有用,對未來有用,那才算到了下一級。這個定義的好處是它不要求你是生物,人工 agent 一樣可以夠得著。

至於"如果你不存在,這件事會不會被別人做掉"這種獨特性檢驗,米庫萊寧覺得門檻太高了。你得是莫扎特才配叫智慧,這顯然不合理。他想保留的是一種區域性效應:這件事因為你而發生了,如果沒有你,它就不會以這個方式發生。範圍可以很小,時間可以很短,但它是真的。

恐懼不是bug,是聚焦機制

訪談裡有一個岔路很有意思。Lex 提到哲學家恩斯特·貝克爾(Ernest Becker)的《否認死亡》,以及恐懼管理理論:人之所以能創造出那麼多東西,是因為我們知道自己會死。

米庫萊寧認這個說法。動物大概不會以這種方式思考死亡,但人知道時間是有限的,所以想讓時間值錢。這個"值錢"的衝動,很大一部分就是創造力的來源。

再往下問:能不能把對死亡的恐懼寫進程式碼裡?他的回答把問題拆開了。恐懼是一種情緒,而情緒的功能是在資訊過載時做篩選。你來不及做邏輯推演,恐懼先跳出來告訴你"現在這個情況很危險",然後你的注意力自動鎖定到關鍵事實上。這是效率機制,談不上什麼玄妙的東西。

所以情緒可以被實現成一種計算狀態:某些輸入被放大,某些被擋在門外。你可以說它不是真正的情緒,但它的行為和我們對情緒的理解高度一致。至於那種"知道自己會死並且因此痛苦",他說得很實在:多數人是知道這件事然後照常過日子,怕到癱瘓是不健康的,完全不在乎也不是正常人的狀態,健康的狀態在中間。

三十隻鬣狗和兩頭獅子的演算法

米庫萊寧的團隊做過一個很具體的模擬:鬣狗搶獅子的獵物。

真實的場景是這樣的。獅子捕到獵物,鬣狗想吃,但單挑必死,獅子一巴掌就能拍死一隻鬣狗。於是鬣狗開始叫,喊同伴。湊到三十隻左右,它們能協同進攻,精確掐時間,把獅子擠走。整個過程裡同時存在兩種互相拉扯的情緒:怕獅子,想離遠點;以及對同伴的強烈歸屬感,想靠過去。再加上第三種:想吃。三種力量疊加,最後歸屬感贏了一點點,它們作為一個整體移動,把事辦成了。

這個行為之所以值得建模,是因為鬣狗智力其實不高。它們比狒狒笨得多,行為模式相當固定。固定才有可觀測性。狒狒和人一樣,腦子裡裝的事太多,你從外面看不出來它在想什麼。鬣狗不一樣,它的動機寫在動作上,甚至能透過糞便裡的化學物質反推過去二十四小時的情緒狀態。

這套模擬給米庫萊寧帶來一個更大的判斷:智慧很大程度上是社會互動的產物。他提到德里克·比克頓(Derek Bickerton)的語言起源理論:先有社會系統,社會里有角色,角色可以互換,我幫你撓揹你幫我撓背。當大腦有了"理解可交換角色"的結構,語法的基礎就有了,然後才能用符號去指代世界上的東西。語言從社會結構裡長出來,是它的一層副產品。

過馬路的那個眼神

Lex 講了一段自動駕駛的觀察。行人走到斑馬線前,和車裡的人對視一眼,然後邁步。這裡面沒有任何複雜的推理,就是一份簡單的社會契約:我信你不會故意撞死我。這份信任建立在雙方共享的道德直覺上,它執行得很好,但你說不清它是怎麼執行的。

現在的機器人不這麼幹。機器人怕一切。它把人類當成彈道物體,套一個大安全包絡,然後離得越遠越好。

米庫萊寧認為不需要真的給機器人裝一套"心智理論"(theory of mind)。功能主義的版本就夠了:預測對方接下來會做什麼,判斷這些預測狀態是好是壞,避開壞的,靠向好的。但一旦進入協作場景,比如兩個人一起抬一個箱子,複雜度就上來了。你得判斷對方此刻處於哪個意圖狀態:他是要抓、要放、還是隻是路過。這個判斷沒法只靠物理軌跡算出來。

再往上一層,你還得預測人的長期目標。他是想出名、想賺錢、還是想做好事?這些資訊能幫你預測他未來幾年會做什麼選擇。層級越高,需要的資訊量越大,但邏輯是同一套。

神經進化:讓進化去設計網路,而不是調權重

進化計算和神經網路的結合,最早是拿進化當替代品,用來訓練權重,代替反向傳播。為什麼需要替代品?因為反向傳播要求你有正確答案,而很多工根本沒有正確答案。機器人走路,走迷宮,玩遊戲,你不知道每一步的最優動作是什麼,梯度無處可回傳。這時候種群加選擇就能頂上。

但米庫萊寧現在更看重的是另一個方向:用進化去設計網路本身。

深度學習的架構已經複雜到人類基本理解不了。為什麼會這樣設計,哪個模組在起什麼作用,很多時候是試出來的。既然人理解不了,那就讓搜尋去幹。可最佳化的物件一下子變得很多:層數、拓撲結構、哪一層接哪一層、每一層用什麼啟用函式、損失函式怎麼定義、資料增強策略怎麼配。整個深度學習實驗的設計空間,都是可以被搜尋的。

他們做過一個很直接的驗證。拿影象描述競賽冠軍的架構,拆成零件,作為搜尋的起點,然後在這個起點周圍搜。結果效能提升 15%。15% 這個數字本身不重要,重要的是它說明了一件事:人類精心調出來的最優架構,周圍還有 15% 的空間沒被挖到。

難點有兩個。第一,搜尋空間太大,你必須先定義清楚"積木"是什麼、怎麼拼,還得有直覺判斷哪些方向值得搜,否則等於什麼都沒約束。第二,評估一個架構好不好,你得真的把它訓出來。一個深度網路訓幾天,一個種群一百個個體,跑一百代,算力賬根本算不過來,碳排放賬更算不過來。能不能不完整訓練就判斷好壞,是這個領域現在最核心的問題之一。

另一條路是先長小的、再長大。Esteban Real 等人做過這類工作:先演化一個小網路,再系統性地擴張。米庫萊寧更感興趣的是模擬真正的生長過程:進化只負責給出一個起點,剩下的交給學習,在個體與環境的互動中長成最終形態。生物就是這麼幹的。人的發育期特別長,因為 DNA 的資訊量根本不夠描述一個成年大腦,進化只能給一個初始設定,剩下的靠學習補。

兩個時間尺度上的機制互相配合:進化在種群尺度上慢,學習在個體生命週期內快。這個組合的潛力,他認為遠沒有被挖完。

斑馬為什麼要分頭跑

捕食者和獵物一起進化,是米庫萊寧團隊做過的最漂亮的實驗之一。合作者是動物學家凱·霍爾坎普(Kay Holekamp),做的是模擬鬣狗和模擬斑馬。

一開始很笨。鬣狗到處亂撞,撞上斑馬就吃,吃到了就很開心。然後斑馬學會了逃,鬣狗學會了包抄,兩隻從不同方向逼近。斑馬的下一個反制是分頭跑,這正是現實中瞪羚被追時的策略,讓捕食者無法鎖定目標。再然後鬣狗加人,把斑馬圍起來趕成一群,一次能吃掉好幾只。

這是一場軍備競賽,而且每一步都是系統自己發現的,沒有一條是寫進去的。這正是競爭性共同進化的價值:它會給你你不知道的東西。

維持這場競賽很難。模擬環境要足夠豐富,才能支撐起越來越複雜的行為。他們只跑出了幾步,但每一步都對應著自然界真實存在的策略。

多工:讓不相干的領域互相幫忙

多工學習這件事,很多人憑直覺就接受:同時學幾種病,比只學一種效果更好,因為一種病逼出來的內部表徵,能幫上另一種病的忙。神經進化在這裡的作用是決定"怎麼合":哪一層合併、合併多少、共享到什麼程度。他的同事埃利奧特·邁耶森(Elliot Meyerson)圍繞這個問題做了不少工作。

真正讓人意外的發現是,任務之間不需要相關。學語言能提升視覺,學 DNA 結構能提升語言。米庫萊寧的說法是世界自己押韻,哪怕表面上看是兩個完全不相干的領域。

這背後是一個更本質的判斷:生物智慧從來不為單一任務構建表徵。它構建的是世界的結構,這個結構能支撐未來的任務,包括你還沒遇到的那些。米庫萊寧把目標定在這裡:造出一個能支撐任意任務集合的表徵,多工表現好只是附帶的收益。

那語言和視覺,哪個更根本?米庫萊寧不選邊。視覺皮層在思考語義概念時也會亮起來,說明底層結構是共用的。人在解釋抽象概念時會本能地畫圖,說明視覺表徵可能比語言更古老。但語言的意義又不止"誰對誰做了什麼",它牽扯目標、計劃、主題,要真正理解一句話,你最終得理解整個社會和歷史。所以他的答案是把兩者綁在一起學:影象加文字的聯合訓練,學到的是更深的語義,而不是兩個模態各自的淺層特徵。他認為這是未來幾年最值得走的方向。

如果外星人來了,我們先做翻譯器

順著語言這條線,米庫萊寧講了一個他覺得該提前做的實驗:在模擬裡讓 agent 進化出真正的語言,然後給這些語言做機器翻譯。

溝通他們已經做出來了,訊號、呼叫、協同,這些很多人做過。但語言不一樣,語言有語法。他想知道的是,在什麼條件下,語法會自己長出來。然後把這些條件換一換:沒有捕食者會怎樣,所有人都是捕食者會怎樣,社會結構完全不同會怎樣。跑足夠多的環境,就能大致圈出"語言可能長成什麼樣"的空間。

這件事的實用價值在於,等外星人真的來了,我們至少做過練習。

同樣的框架也可以套在 AI 上。讓 agent 進化出向人類解釋自己的能力,也就是可解釋 AI 的進化版本。但米庫萊寧提醒了一件事:進化出來的溝通系統,很可能包含撒謊。細菌層面就有 cheater,鬣狗群裡也有。總有一部分個體躲在後面不參與冒險,等別人把獵物搶下來了再湊上去分。

他還專門研究過這個比例:一個群體能容忍多少騙子還能正常運轉。結論是能容忍少數。社會要有效,就必須有信任,而只要有信任,就必然有欺騙的空間。這兩件事是同一個機制的兩面,不可能只取其一。

所以他對"AI 透過圖靈測試"這件事有個不太樂觀的觀察:最早透過圖靈測試的系統,很可能是最會撒謊的那一批。

羅勒不需要睡覺

訪談裡最漂亮的一個實驗,來自和 MIT Media Lab 的合作。他們搞了一個水培的"食物計算機":光、水、營養、溫度,全部由計算機控制。

控制一切意味著什麼?意味著傳統農民的經驗全部失效。農民知道在自己那塊地上怎麼種,那是因為有一堆變數他控制不了、只能適應。當所有變數都能調,人反而不知道該怎麼辦了。

他們做的事是:建一個進化最佳化系統,配一個植物生長的代理模型,讓系統自己去搜配方。最初只搜光照:強度、波長、時長。他們憑常識加了一條約束,每天至少六小時黑暗,因為地球上本來就有晝夜。

系統很快把所有配方都推到了這條邊界上。研究人員看著覺得不對勁,索性把約束去掉,讓它隨便來。結果是:羅勒不需要睡覺。二十四小時光照,長得更大,味道更好。

這對我們是個大驚喜,對團隊裡的生物學家也是。他們原本以為有些約束是自然界本來就有的,是有理由的。結果進化沒有這個偏見。(米庫萊寧)

這裡值得停一下。那些我們以為"生命本來就該這樣"的東西,有多少其實只是"在地球這套約束下的妥協解"?晝夜節律、體型上限、壽命長度,全都長在特定環境裡。去掉約束,答案可能完全不同。

一個會走百萬格之外的井字棋程式

進化計算領域有一篇很好玩的文集,叫《數字進化的驚人創造力》(The Surprising Creativity of Digital Evolution),收集了各路研究者被自己的系統驚到的經歷。米庫萊寧貢獻了一個小的。

他的課上有期末專案,讓學生進化神經網路下井字棋(在一個很大的棋盤上玩五子棋)。有一個隊的程式贏了錦標賽,而且大部分勝局是因為對手崩潰。

查下去發現,進化出來的策略是:把棋子下到幾百萬格之外。對手程式為了處理這個座標,不斷擴張記憶體,最後記憶體耗盡,直接掛掉。

這件事的隱喻意義超過一個課堂作業。贏不一定靠在規則內做得更好,有時候靠在對手的認知邊界上做文章。卡斯帕羅夫輸給深藍之後說過類似的話:深藍下的不是他預期的那種棋。AI 的優勢恰恰在於沒有人類那些偏見。人類棋手不會考慮某步棋,因為"那不是一步好棋",而這個判斷本身來自訓練出來的先驗。搜尋不帶這個先驗,所以它能走到人類走不到的地方,包括一些看起來荒謬、實際管用的地方。

進化計算的骨架,以及它和生物學的分歧

剝掉細節,進化計算的骨架只有兩件事:製造變異,然後對變異做選擇。

變異需要一個數字化的個體表示,也就是基因型,還要有一個解碼機制把它變成表現型,也就是真正在環境裡幹活、被打分的那個東西。表示通常是數字串或者樹,因為電腦科學對這兩種結構最熟。DNA 某種意義上也是字串,但它有摺疊、有空間互動,這些在計算模型裡基本沒被捕捉。而我們已經不知道這些東西是不是關鍵。

製造變異有兩種方式:交叉和變異。生物進化裡交叉是主力,把兩條 DNA 切開再拼上。計算裡主要靠變異,也就是往染色體上隨機改幾處。過去二十年這個領域的進步,很大一部分來自用統計去引導變異:收集效能資料,找到哪些位置重要、哪些改動方向有效,然後有方向地改。這和機器學習其他分支的思路一致,也讓進化計算離生物進化更遠了一點。

米庫萊寧覺得這裡可以往回走一步:選擇壓力弱一點,交叉多一點,種群大一點,時間給足一點。生物學不著急,計算很著急。我們今天做進化計算,一個個體不行就殺掉,追求儘快收斂到最優指標,而生物進化有深時間、有弱壓力、有大種群,還有無數種成功的方式:可以更強、更快、更大、更聰明,可以吃這個也可以吃那個,可以佔據一個生態位躲起來。目標只有一個,解就會單一;目標有無數個,創造力才會出來。

他覺得這套耐心的方法也許能催生另一種創造力。代價是慢,而人類等不起。

什麼時候用進化,什麼時候用深度學習

米庫萊寧劃的線很清楚。

深度學習吃資料,尤其是帶標註的資料。它能做得很好的領域,是那種"正確答案已知"的問題,甚至包括天氣預報這種資料本身就能當標籤的場景。

但大量真實任務沒有標準答案。下棋、機器人動作、醫療決策、投資,你不知道最優解是什麼,也永遠不會知道。這類問題上,強化學習和進化計算各自有一套。

強化學習是個體在生命週期內學習:吃到好果子就多吃,吃壞了就記住。進化計算是在種群尺度上做工程:它不在乎任何一個個體經歷了什麼,只在乎最後剩下的那個解。個體死掉沒關係,下一代更好就行。

選擇依據是試錯成本。如果每次嘗試都很貴,用強化學習,因為它更謹慎、更會利用已有資訊。如果能建代理模型,試錯便宜,而且你想要意外之喜,那就用種群方法,因為它能去探索那些強化學習不敢碰的區域。

兩個演算法教機器人走路,影片擺在一起對比,差別一眼就能看出來。強化學習的 agent 追求穩定,走得小心,因為它要儘可能活得久。進化計算允許個體摔得鼻青臉腫,先摔一跤,再摔一跤,然後在摔倒中學會了控制摔倒,最後跑起來了,跑得還很快。

這些摔跤很少是白摔。兩個摔得很難看的步態,組合起來可能正好是能跑的那一個。進化允許這種跳躍,因為它不要求每一步都是改進。

身體和控制器一起進化,你會相信它是活的

米庫萊寧還做過虛擬生物的實驗:不只是控制器,連身體一起進化。圓柱體是骨骼,關節、肌肉、感測器,都由搜尋決定。

結果出來的形態五花八門,有的很多腿,有的一條腿都沒有。目標是移動,是走,是跑。

最能說明問題的一點是:當身體和控制器一起最佳化時,動作看起來是自然的。因為這些動作是為那個特定身體量身定製的,你會本能地覺得"長成這樣的東西就該這麼走"。看著看著,你會開始相信它們是活的。

這引出一個他覺得很難的問題。波士頓動力的機器人跳舞影片,那些動作全是人編排的。硬編碼一段編舞不難,難的是讓機器人自己學出自然和優雅,學出那種讓人願意與之共處的動作質感。物理世界裡太難,唯一的希望是在模擬裡學,再遷移過去,前提是模擬足夠真。

還有一個更妙的實驗,肯·斯坦利做的。兩個機器人在模擬裡覓食,攢夠了能量、變強了以後,可以撞對方,強的贏。進化先教它們去最近的食物,然後教它們規劃路線一次拿更多,再然後,它們開始盯著對方在幹什麼。

最高階的那個策略是這樣的:場上有三塊食物,兩塊在很遠的地方,一塊在附近,對手離那兩塊遠的很近。這個機器人假裝朝那兩塊遠食物移動,引誘對手跑過去,對手跑一趟耗光能量,它自己回頭把近的那塊吃掉,贏下比賽。

用人類的話說,這叫欺騙,而且需要對對手的心智有模型。這套東西沒有任何一行是寫進去的,是競爭逼出來的。

複雜度從簡單規則裡湧出來,人的直覺在這裡完全失效

Lex 提到康威的生命遊戲,提到約翰·康威不久前去世。米庫萊寧的回應很坦誠:這類系統最震撼的地方在於,你的直覺在這裡完全不管用。

幾條規則,格子非生即死,然後複雜性就湧出來了。DNA 也是一樣,本質是一長串簡單的符號,操作它的程式碼量少得可憐。進化計算裡的表示和運算元,程式碼量同樣很小。複雜性的來源在於非線性互動,而不在規則本身的複雜程度。

進化本身沒有目標。它只是對當下環境做出反應,活下來的留下,然後你就看到了被我們稱為"進步"的東西。生命遊戲也是這樣,它只是在跑,沒有人給它打分。

這裡有一個叫"新奇搜尋"(novelty search)的方法值得單獨說。肯·斯坦利和喬爾·雷曼做過一個實驗:不給任何適應度目標,只獎勵和已有解不一樣的東西。結果它進化出了非常高效的走路行為。

為什麼這麼幹有效?米庫萊寧的解釋是:要真正遠離已有的解,你必須先把這個世界的基本結構編碼進去。系統走得不亂,它在基本結構之上做大幅改動。所以新奇搜尋實際上是在逼系統理解世界,然後在這個理解之上跳躍。在這個過程中,絕大部分產物是垃圾,但垃圾堆裡會有寶石。

難的地方在於,寶石得靠外部的人認出來。

關於怎麼活,一個進化計算學者的答案

Lex 問了一個很大的問題:從進化和計算的角度,對年輕人有什麼建議?

米庫萊寧的答案是:探索,而且是深度探索。去上音樂課、歷史課、哲學課、數學課、工程課,然後看它們之間的連線。去旅行,學一門語言。今天這些東西都在手邊,但需要你主動伸手。

他特意強調"深度"。別淺嘗輒止地試一百件事,選幾件真正鑽進去,鑽到自己判斷"這個領域我能拿的都拿到了",再換下一個。這個過程可能要幾年。有人十年換一次賽道,完全可以。要成為專家需要一萬小時,你不一定要成為專家,但要有足夠的理解,讓這段經歷在以後用得上。

然後是第二階段:探索到某個時刻,你會碰到一個離不開的東西。對他自己是計算機和 AI。那時候就可以沉下去,做幾十年,把之前所有的經歷都帶進來。順序很重要:先探索,後承諾。探索在前,你才有做選擇的資格。

關於死亡,他講得很實在。年輕時跳傘、玩滑翔傘,現在想得比那時候多。這個變化有道理:年輕人在做探索,所以他們必須不怕,得有人願意翻過那座山看看後面是什麼。年紀大一些,探索做得差不多了,方向也定了,問題就變成:在有限的時間和資源裡,我能做點什麼真正重要的。留下一點痕跡,哪怕 agent 消失之後,痕跡還在。

關於個體在進化這臺機器裡的意義,他的說法是這樣的:每個個體都是一個可能的方向,一塊可能的踏腳石。有些走得通,成為後續改進的基礎;有些走不通,但走不通的也不算白費。恐龍曾經是非常好的解,環境一變就不是了。可恐龍還在,它們的親戚還在我們身邊。誰知道哪天又變得有用了。

一個人是巨大創新引擎裡的一個小齒輪,這件事聽起來讓人失落。但米庫萊寧覺得它給出的是意義感:你屬於一個比你更大的東西。

他見過最美的東西,是程式碼給出他沒寫過的答案

訪談最後,Lex 問什麼是你見過最美的、受自然啟發的演算法。

米庫萊寧說的是大一那年。他寫了一段很簡單的程式,機器接過數字,算出結果。他自己不用算。就這麼簡單的一件事,讓他呆住了。

然後是這條線的延伸。機器可以學習,可以識別出人類都覺得吃力的模式,有時候做得比人還好。再往前一步,進化演算法可以發現你沒想到的解,因為它不帶你的偏見。人類預期解應該長這樣,演算法不知道解應該長什麼樣,所以它更自由。

我們可以造出某種意義上比我們更聰明的系統,它們能發現我們會漏
我們可以造出某種意義上比我們更聰明的系統,它們能發現我們會漏掉的解。這讓我震撼。(米庫萊寧)

他對創造力的定義很清晰,也很可操作:新的、有用的、令人驚訝的。三條同時滿足,就是創造。按這個標準,演算法確實可以創造,上面那個羅勒不需要睡覺的發現,三條全中。

這也是他對"造出比自己更大的東西"這件事的熱情來源。程式跑出來的東西超出了你寫下的那些,那一刻的感覺,他說,跟看著一個有生命的東西長大是一樣的。你給了它一個起點,然後它去過它自己的生活。

關於腦機介面,他的判斷分兩半。修復功能這一側,大腦的可塑性遠超預期,把聽覺訊號接到視覺皮層,動物仍然能"看見";切掉一半大腦的孩子,功能會遷移到剩下那一半。所以作為假肢、作為功能替代,路是通的。擴充套件智慧是另一回事。給大腦塞更多輸入,很可能只是把它淹沒,它得先學會過濾和聚焦,而這套機制本來就是它最擅長也最耗力的部分。他對"頻寬一開、智慧指數級暴漲"這個想象持保留態度。

他的觀察是,擴充套件早就開始了,只是不在顱骨裡面。手機已經是一個隨時可查的外部記憶。孩子在小學就學 DNA 雙螺旋,那是幾十年前才被發現的東西。資訊量漲了這麼多,人類並沒有飽和。這一代人的知識面可能變窄了,只在一個領域裡深,但積累下來的東西在被一代代接手,然後往上壘。篩掉什麼、留下什麼,這個機制還在工作,哪怕資訊量比五十年前大了幾個數量級。視覺本身就是最好的證明:眼睛每秒送進來的資料量遠超大腦的處理能力,它一直在做取捨,而且做得很好。

多樣性的價值,以及為什麼必須容忍幾個混蛋

關於未來怎麼部署 AI,米庫萊寧有一個從進化計算直接推出來的建議。假設真造出了 AGI,然後一模一樣地複製幾百萬份鋪到世界上,這在工程上很省事,在戰略上很危險。

因為多樣性是進化執行的命脈。跑一個進化演算法,第一件必須保證的事就是種群裡得有差異。全都一樣,搜尋就停了。他自己舉了個不太體面的例子:鬣狗模擬裡出現過自殺式的個體,衝上去就被咬死,看起來完全是浪費。可正是這些個體構成了基礎,讓那些跑得快、又能在被殺之前停住的個體有機會出現,最後聚成能搶下獵物的群體。如果沒有那些看起來毫無價值的失敗者,那個能成事的解根本長不出來。

所以對 AI 系統來說,留一點看起來不聽話、不守規矩的個體,可能是有價值的。容忍幾個騙子,容忍幾個鑽規則空子的,因為規則本身也在變。回頭看看人類社會,很多曾經被視為正當的行為現在看是不公正的,很多曾經違規的行為後來成了新規範。改變往往就是從那些不合規矩的個體開始的。

當然有個度。他研究過那個比例:群體能扛住多少 cheater 還不散架。結論是少數可以,多了不行。

如果有一批 agent 能夠互相信任,它們能做成的事情多得多。但只要有信任,就一定有欺騙的空間。我覺得這件事永遠不會消失。(米庫萊寧)

他還提了一個更深遠的角度:社會本身也可以被看作一種生命形式。生物進化走得很慢,但觀念、制度、文化的進化快得多。人類這一千年在生物學上幾乎沒變,可我們已經在理解 DNA 和基本粒子了,因為思想的複製和變異比基因快太多。按道金斯的說法,真正在進化的是模因,人是載體。AI 在這個框架裡也是模因進化的下一步,是我們造出來的工具,是我們這套快速進化的一部分。

至於人類的認知上限,他承認可能存在。宇宙也許執行在人類大腦根本無法內化的維度上,物理學的某些結構我們可能永遠沒法真正"理解",只能透過抽象介面去操作它,就像大多數人開車時並不理解車上幾百個部件是怎麼工作的,但照樣能開。不理解底層,靠抽象層操作,這件事人類已經幹了幾千年。AI 可以成為新的那一層抽象。

他的研究裡還缺一塊:重大轉變

米庫萊寧自己點出了這個領域的空白。生物學史上發生過幾次"重大轉變":單細胞變成多細胞,個體變成社會。每一次都是選擇單位的躍遷,一個細胞原本可以自己繁殖,加入多細胞生物之後它單獨活不了了,它的適應度不再由自己決定,而由它所在的那個整體決定。

進化計算裡從來沒出現過這種事。不是沒人試,是連生物學自己都沒搞清楚這個躍遷是怎麼發生的。要復現它,大機率需要表示方式的根本性擴充套件,而現在大家手裡的工具只有字串和樹。

這件事他講得很平靜,但分量很重。這個領域最有名的成果,都還是在一個固定的選擇層級上做最佳化。真正的躍遷,一次都沒有。

Carl Sagan 那句話

訪談的結尾,Lex 引了卡爾·薩根的一句話:滅絕是規律,存活是例外。

這句話放在整場對話的語境裡,比它單獨出現時更扎人。地球跑了四十億年,出現過的大部分物種都消失了。鬣狗群裡那些衝上去被拍死的個體,模擬裡那些跑得歪歪扭扭最終被淘汰的機器人,都是這條規律的註腳。可正是這些註定消失的東西,構成了活著的東西的踏腳石。

米庫萊寧沒有把這件事說成悲觀的。他說的是:個體是可能的方向,是潛在的踏腳石,有些成了基礎,有些沒有。這個描述裡沒有安慰的成分,也沒有恐嚇的成分,就是機制本身。

至於怎麼用好自己這一段有限的時間,他的答案落到兩個動作上:先把探索做得足夠深,找到那個你離不開的東西,然後沉下去做幾十年,做出來的東西要比你自己的存在多活一段時間。

下面是這場對話裡可以直接拿走的東西。

  • 給搜尋留出意外空間。如果你在設計任何帶目標函式的東西,包括自己的年度計劃,試著留一部分不看指標、只看"和以前不一樣"。羅勒不需要睡覺這個發現,就是去掉約束之後撞出來的。
  • 別讓所有例項長得一樣。部署一堆完全相同的 AI 系統或完全相同的策略,等於把搜尋關掉。留一些差異,哪怕其中有幾個看起來不靠譜。
  • 容忍少數不合規矩的個體。一個團隊全員完全一致,意味著一件事:沒人能提出規則之外的可能性。比例控制在少數就行,多了會散架。
  • 關鍵任務上,先問有沒有標準答案。有標註資料、有明確正確答案的問題,用監督學習。沒有標準答案、也永遠不會有的問題,才需要進化或強化學習這類靠試錯的方法。選錯方法的代價比調錯引數大得多。
  • 試錯成本決定演算法選擇。每次嘗試都很貴的時候用強化學習,它更會利用已有資訊;能建代理模型、試錯便宜且想要意外之喜的時候用種群方法。這條判斷比看哪個方法最近更火更靠譜。
  • 嘗試跨領域地學一件不相干的東西。學語言能提升視覺,學 DNA 結構能提升語言。世界的結構是押韻的,跨界的收益往往不在你預期的地方出現。
  • 探索要深,不要廣而淺。選幾件事鑽到自己判斷"能拿的都拿到了"再換。這個判斷本身才是探索的成果。
  • 先探索,後承諾,別搞反。沒有做過功課就定方向,等於在一個沒搜尋過的空間裡做區域性最優。年輕人最該乾的事是擴大搜尋範圍,不必急著鎖定。
  • 給自己找一個能沉幾十年的題目。探索結束後必須有一個東西讓你停下來。找到它之後,之前所有的經歷都會變成這個題目的資源。
  • 想一想自己留下的痕跡。不必是莫扎特。標準很低:這件事因為你而發生了,如果沒有你,它不會以這個方式發生。範圍可以很小,但它得是真的。
文稿來自公開 Kaggle 資料集(rajneesh231/lex-fridman-podcast-transcript),為早期自動轉錄存檔,可能存在識別錯誤。
The following is a conversation with Risto Michaelainen, a computer scientist at University of Texas at Austin and Associate Vice President of Evolutionary Artificial Intelligence at Cognizant. He specializes in evolutionary computation, but also many other topics in artificial intelligence, cognitive science, and neuroscience. Quick mention of our sponsors, Jordan Harbin's show, Grammarly, Belcampo, and Indeed. Check them out in the description to support this podcast. As a side note, let me say that nature inspired algorithms from ant colony optimization to genetic algorithms to cellular automata to neural networks have always captivated my imagination, not only for their surprising power in the face of long odds, but because they always opened up doors to new ways of thinking about computation. It does seem that in the long arc of computing history, running toward biology, not running away from it is what leads to long term progress. This is the Lex Friedman podcast, and here is my conversation with Risto Michaelainen. If we ran the Earth experiment, this fun little experiment we're on, over and over and over and over a million times and watch the evolution of life as it pans out, how much variation in the outcomes of that evolution do you think we would see? Now, we should say that you are a computer scientist. That's actually not such a bad question for a computer scientist, because we are building simulations of these things, and we are simulating evolution, and that's a difficult question to answer in biology, but we can build a computational model and run it million times and actually answer that question. How much variation do we see when we simulate it? And that's a little bit beyond what we can do today, but I think that we will see some regularities, and it took evolution also a really long time to get started, and then things accelerated really fast towards the end. But there are things that need to be discovered, and they probably will be over and over again, like manipulation of objects, opposable thumbs, and also some way to communicate, maybe orally, like when you have speech, it might be some other kind of sounds, and decision making, but also vision. Eye has evolved many times. Various vision systems have evolved. So we would see those kinds of solutions, I believe, emerge over and over again. They may look a little different, but they get the job done. The really interesting question is, would we have primates? Would we have humans or something that resembles humans? And would that be an apex of evolution after a while? We don't know where we're going from here, but we certainly see a lot of tool use and building, constructing our environment. So I think that we will get that. We get some evolution producing, some agents that can do that, manipulate the environment and build. What do you think is special about humans? Like if you were running the simulation and you observe humans emerge, like these tool makers, they start a fire and all this stuff, start running around, building buildings, and then running for president and all those kinds of things. What would be, how would you detect that? Cause you're like really busy as the creator of this evolutionary system. So you don't have much time to observe, like detect if any cool stuff came up, right? How would you detect humans? Well, you are running the simulation. So you also put in visualization and measurement techniques there. So if you are looking for certain things like communication, you'll have detectors to find out whether that's happening, even if it's a large simulation. And I think that that's what we would do. We know roughly what we want, intelligent agents that communicate, cooperate, manipulate, and we would build detections and visualizations of those processes. Yeah, and there's a lot of, we'd have to run it many times and we have plenty of time to figure out how we detect the interesting things. But also, I think we do have to run it many times because we don't quite know what shape those will take and our detectors may not be perfect for them at the beginning. Well, that seems really difficult to build a detector of intelligent or intelligent communication. Sort of, if we take an alien perspective, observing earth, are you sure that they would be able to detect humans as the special thing? Wouldn't they be already curious about other things? There's way more insects by body mass, I think, than humans by far, and colonies. Obviously, dolphins is the most intelligent creature on earth, we all know this. So it could be the dolphins that they detect. It could be the rockets that we seem to be launching. That could be the intelligent creature they detect. It could be some other trees. Trees have been here a long time. I just learned that sharks have been here 400 million years and that's longer than trees have been here. So maybe it's the sharks, they go by age. Like there's a persistent thing. Like if you survive long enough, especially through the mass extinctions, that could be the thing your detector is detecting. Humans have been here for a very short time and we're just creating a lot of pollution, but so is the other creatures. So I don't know, do you think you'd be able to detect humans? Like how would you go about detecting in the computational sense? Maybe we can leave humans behind. In the computational sense, detect interesting things. Do you basically have to have a strict objective function by which you measure the performance of a system or can you find curiosities and interesting things? Yeah, well, I think that the first measurement would be to detect how much of an effect you can have in your environment. So if you look around, we have cities and that is constructed environments. And that's where a lot of people live, most people live. So that would be a good sign of intelligence that you don't just live in an environment, but you construct it to your liking. And that's something pretty unique. I mean, there are certainly birds build nests but they don't build quite cities. Termites build mounds and ice and things like that. But the complexity of the human construction cities, I think would stand out even to an external observer. Of course, that's what a human would say. Yeah, and you know, you can certainly say that sharks are really smart because they've been around so long and they haven't destroyed their environment, which humans are about to do, which is not a very smart thing. But we'll get over it, I believe. And we can get over it by doing some construction that actually is benign and maybe even enhances the resilience of nature. So you mentioned the simulation that we run over and over might start, it's a slow start. So do you think how unlikely, first of all, I don't know if you think about this kind of stuff, but how unlikely is step number zero, which is the springing up, like the origin of life on earth? And second, how unlikely is the, anything interesting happening beyond that? So like the start that creates all the rich complexity that we see on earth today. Yeah, there are people who are working on exactly that problem from primordial soup. How do you actually get self replicating molecules? And they are very close. With a little bit of help, you can make that happen. So of course we know what we want, so they can set up the conditions and try out conditions that are conducive to that. For evolution to discover that, that took a long time. For us to recreate it probably won't take that long. And the next steps from there, I think also with some handholding, I think we can make that happen. But with evolution, what was really fascinating was eventually the runaway evolution of the brain that created humans and created, well, also other higher animals, that that was something that happened really fast. And that's a big question. Is that something replicable? Is that something that can happen? And if it happens, does it go in the same direction? That is a big question to ask. Even in computational terms, I think that it's relatively possible to come up here, create an experiment where we look at the primordial soup and the first couple of steps of multicellular organisms even. But to get something as complex as the brain, we don't quite know the conditions for that. And how do you even get started and whether we can get this kind of runaway evolution happening? From a detector perspective, if we're observing this evolution, what do you think is the brain? What do you think is the, let's say, what is intelligence? So in terms of the thing that makes humans special, we seem to be able to reason, we seem to be able to communicate. But the core of that is this something in the broad category we might call intelligence. So if you put your computer scientist hat on, is there a favorite ways you like to think about that question of what is intelligence? Well, my goal is to create agents that are intelligent. Not to define what. And that is a way of defining it. And that means that it's some kind of an object or a program that has limited sensory and effective capabilities interacting with the world. And then also a mechanism for making decisions. So with limited abilities like that, can it survive? Survival is the simplest goal, but you could also give it other goals. Can it multiply? Can it solve problems that you give it? And that is quite a bit less than human intelligence. There are, animals would be intelligent, of course, with that definition. And you might have even some other forms of life, even. So intelligence in that sense is a survival skill given resources that you have and using your resources so that you will stay around. Do you think death, mortality is fundamental to an agent? So like there's, I don't know if you're familiar, there's a philosopher named Ernest Becker who wrote The Denial of Death and his whole idea. And there's folks, psychologists, cognitive scientists that work on terror management theory. And they think that one of the special things about humans is that we're able to sort of foresee our death, right? We can realize not just as animals do, sort of constantly fear in an instinctual sense, respond to all the dangers that are out there, but like understand that this ride ends eventually. And that in itself is the force behind all of the creative efforts of human nature. That's the philosophy. I think that makes sense, a lot of sense. I mean, animals probably don't think of death the same way, but humans know that your time is limited and you wanna make it count. And you can make it count in many different ways, but I think that has a lot to do with creativity and the need for humans to do something beyond just surviving. And now going from that simple definition to something that's the next level, I think that that could be the second level of definition, that intelligence means something, that you do something that stays behind you, that's more than your existence. You create something that is useful for others, is useful in the future, not just for yourself. And I think that's the nicest definition of intelligence within a next level. And it's also nice because it doesn't require that they are humans or biological. They could be artificial agents that are intelligence. They could achieve those kind of goals. So particular agent, the ripple effects of their existence on the entirety of the system is significant. So like they leave a trace where there's like a, yeah, like ripple effects. But see, then you go back to the butterfly with the flap of a wing and then you can trace a lot of like nuclear wars and all the conflicts of human history, somehow connected to that one butterfly that created all of the chaos. So maybe that's not, maybe that's a very poetic way to think that that's something we humans in a human centric way wanna hope we have this impact. Like that is the secondary effect of our intelligence. We've had the long lasting impact on the world, but maybe the entirety of physics in the universe has a very long lasting effects. Sure, but you can also think of it. What if like the wonderful life, what if you're not here? Will somebody else do this? Is it something that you actually contributed because you had something unique to compute? That contribute, that's a pretty high bar though. Uniqueness, yeah. So, you have to be Mozart or something to actually reach that level that nobody would have developed that, but other people might have solved this equation if you didn't do it, but also within limited scope. I mean, during your lifetime or next year, you could contribute something that unique that other people did not see. And then that could change the way things move forward for a while. So, I don't think we have to be Mozart to be called intelligence, but we have this local effect that is changing. If you weren't there, that would not have happened. And it's a positive effect, of course, you want it to be a positive effect. Do you think it's possible to engineer into computational agents, a fear of mortality? Like, does that make any sense? So, there's a very trivial thing where it's like, you could just code in a parameter, which is how long the life ends, but more of a fear of mortality, like awareness of the way that things end and somehow encoding a complex representation of that fear, which is like, maybe as it gets closer, you become more terrified. I mean, there seems to be something really profound about this fear that's not currently encodable in a trivial way into our programs. Well, I think you're referring to the emotion of fear, something, because we have cognitively, we know that we have limited lifespan and most of us cope with it by just, hey, that's what the world is like and I make the most of it. But sometimes you can have like a fear that's not healthy, that paralyzes you, that you can't do anything. And somewhere in between there, not caring at all and getting paralyzed because of fear is a normal response, which is a little bit more than just logic and it's emotion. So now the question is, what good are emotions? I mean, they are quite complex and there are multiple dimensions of emotions and they probably do serve a survival function, heightened focus, for instance. And fear of death might be a really good emotion when you are in danger, that you recognize it, even if it's not logically necessarily easy to derive and you don't have time for that logical deduction, you may be able to recognize the situation is dangerous and this fear kicks in and you all of a sudden perceive the facts that are important for that. And I think that's generally is the role of emotions. It allows you to focus what's relevant for your situation. And maybe if fear of death plays the same kind of role, but if it consumes you and it's something that you think in normal life when you don't have to, then it's not healthy and then it's not productive. Yeah, but it's fascinating to think how to incorporate emotion into a computational agent. It almost seems like a silly statement to make, but it perhaps seems silly because we have such a poor understanding of the mechanism of emotion, of fear, of, I think at the core of it is another word that we know nothing about, but say a lot, which is consciousness. Do you ever in your work, or like maybe on a coffee break, think about what the heck is this thing consciousness and is it at all useful in our thinking about AI systems? Yes, it is an important question. You can build representations and functions, I think into these agents that act like emotions and consciousness perhaps. So I mentioned emotions being something that allow you to focus and pay attention, filter out what's important. Yeah, you can have that kind of a filter mechanism and it puts you in a different state. Your computation is in a different state. Certain things don't really get through and others are heightened. Now you label that box emotion. I don't know if that means it's an emotion, but it acts very much like we understand what emotions are. And we actually did some work like that, modeling hyenas who were trying to steal a kill from lions, which happens in Africa. I mean, hyenas are quite intelligent, but not really intelligent. And they have this behavior that's more complex than anything else they do. They can band together, if there's about 30 of them or so, they can coordinate their effort so that they push the lions away from a kill. Even though the lions are so strong that they could kill a hyena by striking with a paw. But when they work together and precisely time this attack, the lions will leave and they get the kill. And probably there are some states like emotions that the hyenas go through. The first, they call for reinforcements. They really want that kill, but there's not enough of them. So they vocalize and there's more people, more hyenas that come around. And then they have two emotions. They're very afraid of the lion, so they want to stay away, but they also have a strong affiliation between each other. And then this is the balance of the two emotions. And also, yes, they also want the kill. So it's both repelled and attractive. But then this affiliation eventually is so strong that when they move, they move together, they act as a unit and they can perform that function. So there's an interesting behavior that seems to depend on these emotions strongly and makes it possible, coordinate the actions. And I think a critical aspect of that, the way you're describing is emotion there is a mechanism of social communication, of a social interaction. Maybe humans won't even be that intelligent or most things we think of as intelligent wouldn't be that intelligent without the social component of interaction. Maybe much of our intelligence is essentially an outgrowth of social interaction. And maybe for the creation of intelligent agents, we have to be creating fundamentally social systems. Yes, I strongly believe that's true. I've gotten a chance in the autonomous vehicle space to watch vehicles interact with pedestrians or pedestrians interacting with vehicles in general. I mean, you would think that there's a very complicated theory of mind thing going on, but I have a sense, it's not well understood yet, but I have a sense it's pretty dumb. Like it's pretty simple. There's a social contract there between humans, a human driver and a human crossing the road where the human crossing the road trusts that the human in the car is not going to murder them. And there's something about, again, back to that mortality thing. There's some dance of ethics and morality that's built in, that you're mapping your own morality onto the person in the car. And even if they're driving at a speed where you think if they don't stop, they're going to kill you, you trust that if you step in front of them, they're going to hit the brakes. And there's that weird dance that we do that I think is a pretty simple model, but of course it's very difficult to introspect what it is. And autonomous robots in the human robot interaction context have to build that. Current robots are much less than what you're describing. They're currently just afraid of everything. They're more, they're not the kind that fall and discover how to run. They're more like, please don't touch anything. Don't hurt anything. Stay as far away from humans as possible. Treat humans as ballistic objects that you can't, that you do with a large spatial envelope, make sure you do not collide with. That's how, like you mentioned, Elon Musk thinks about autonomous vehicles. I tend to think autonomous vehicles need to have a beautiful dance between human and machine, where it's not just the collision avoidance problem, but a weird dance. Yeah, I think these systems need to be able to predict what will happen, what the other agent is going to do, and then have a structure of what the goals are and whether those predictions actually meet the goals. And you can go probably pretty far with that relatively simple setup already, but to call it a theory of mind, I don't think you need to. I mean, it doesn't matter whether the pedestrian has a mind, it's an object, and we can predict what we will do. And then we can predict what the states will be in the future and whether they are desirable states. Stay away from those that are undesirable and go towards those that are desirable. So it's a relatively simple functional approach to that. Where do we really need the theory of mind? Maybe when you start interacting and you're trying to get the other agent to do something and jointly, so that you can jointly, collaboratively achieve something, then it becomes more complex. Well, I mean, even with the pedestrians, you have to have a sense of where their attention, actual attention in terms of their gaze is, but also there's this vision science, people talk about this all the time. Just because I'm looking at it doesn't mean I'm paying attention to it. So figuring out what is the person looking at? What is the sensory information they've taken in? And the theory of mind piece comes in is what are they actually attending to cognitively? And also what are they thinking about? Like what is the computation they're performing? And you have probably maybe a few options for the pedestrian crossing. It doesn't have to be, it's like a variable with a few discrete states, but you have to have a good estimation which of the states that brain is in for the pedestrian case. And the same is for attending with a robot. If you're collaborating to pick up an object, you have to figure out is the human, like there's a few discrete states that the human could be in. You have to predict that by observing the human. And that seems like a machine learning problem to figure out what's the human up to. It's not as simple as sort of planning just because they move their arm means the arm will continue moving in this direction. You have to really have a model of what they're thinking about and what's the motivation behind the movement of the arm. Here we are talking about relatively simple physical actions, but you can take that the higher levels also like to predict what the people are going to do, you need to know what their goals are. What are they trying to, are they exercising? Are they just starting to get somewhere? But even higher level, I mean, you are predicting what people will do in their career, what their life themes are. Do they want to be famous, rich, or do good? And that takes a lot more information, but it allows you to then predict their actions, what choices they might make. So how does evolution and computation apply to the world of neural networks? I've seen quite a bit of work from you and others in the world of neural evolution. So maybe first, can you say, what is this field? Yeah, neural evolution is a combination of neural networks and evolution computation in many different forms, but the early versions were simply using evolution as a way to construct a neural network instead of say, stochastic gradient descent or backpropagation. Because evolution can evolve these parameters, weight values in a neural network, just like any other string of numbers, you can do that. And that's useful because some cases you don't have those targets that you need to backpropagate from. And it might be an agent that's running a maze or a robot playing a game or something. You don't, again, you don't know what the right answers are, you don't have backprop, but this way you can still evolve a neural net. And neural networks are really good at these tasks, because they recognize patterns and they generalize, interpolate between known situations. So you want to have a neural network in such a task, even if you don't have a supervised targets. So that's a reason and that's a solution. And also more recently, now when we have all this deep learning literature, it turns out that we can use evolution to optimize many aspects of those designs. The deep learning architectures have become so complex that there's little hope for us little humans to understand their complexity and what actually makes a good design. And now we can use evolution to give that design for you. And it might mean optimizing hyperparameters, like the depth of layers and so on, or the topology of the network, how many layers, how they're connected, but also other aspects like what activation functions you use where in the network during the learning process, or what loss function you use, you could generalize that. You could generate that, even data augmentation, all the different aspects of the design of deep learning experiments could be optimized that way. So that's an interaction between two mechanisms. But there's also, when we get more into cognitive science and the topics that we've been talking about, you could have learning mechanisms at two level timescales. So you do have an evolution that gives you baby neural networks that then learn during their lifetime. And you have this interaction of two timescales. And I think that can potentially be really powerful. Now, in biology, we are not born with all our faculties. We have to learn, we have a developmental period. In humans, it's really long and most animals have something. And probably the reason is that evolution of DNA is not detailed enough or plentiful enough to describe them. We can describe how to set the brain up, but we can, evolution can decide on a starting point and then have a learning algorithm that will construct the final product. And this interaction of intelligent, well, evolution that has produced a good starting point for the specific purpose of learning from it with the interaction with the environment, that can be a really powerful mechanism for constructing brains and constructing behaviors. I like how you walk back from intelligence. So optimize starting point, maybe. Yeah, okay, there's a lot of fascinating things to ask here. And this is basically this dance between neural networks and evolution and computation could go into the category of automated machine learning to where you're optimizing, whether it's hyperparameters of the topology or hyperparameters taken broadly. But the topology thing is really interesting. I mean, that's not really done that effectively or throughout the history of machine learning has not been done. Usually there's a fixed architecture. Maybe there's a few components you're playing with, but to grow a neural network, essentially, the way you grow an organism is really fascinating space. How hard is it, do you think, to grow a neural network? And maybe what kind of neural networks are more amenable to this kind of idea than others? I've seen quite a bit of work on recurrent neural networks. Is there some architectures that are friendlier than others? And is this just a fun, small scale set of experiments or do you have hope that we can be able to grow powerful neural networks? I think we can. And most of the work up to now is taking architectures that already exist that humans have designed and try to optimize them further. And you can totally do that. A few years ago, we did an experiment. We took a winner of the image captioning competition and the architecture and just broke it into pieces and took the pieces. And that was our search base. See if you can do better. And we indeed could, 15% better performance by just searching around the network design that humans had come up with, Oreo vinyls and others. So, but that's starting from a point that humans have produced, but we could do something more general. It doesn't have to be that kind of network. The hard part is, there are a couple of challenges. One of them is to define the search base. What are your elements and how you put them together. And the space is just really, really big. So you have to somehow constrain it and have some hunch what will work because otherwise everything is possible. And another challenge is that in order to evaluate how good your design is, you have to train it. I mean, you have to actually try it out. And that's currently very expensive, right? I mean, deep learning networks may take days to train while imagine you having a population of a hundred and have to run it for a hundred generations. It's not yet quite feasible computationally. It will be, but also there's a large carbon footprint and all that. I mean, we are using a lot of computation for doing it. So intelligent methods and intelligent, I mean, we have to do some science in order to figure out what the right representations are and right operators are, and how do we evaluate them without having to fully train them. And that is where the current research is and we're making progress on all those fronts. So yes, there are certain architectures that are more amenable to that approach, but also I think we can create our own architecture and all representations that are even better at that. And do you think it's possible to do like a tiny baby network that grows into something that can do state of the art on like even the simple data set like MNIST, and just like it just grows into a gigantic monster that's the world's greatest handwriting recognition system? Yeah, there are approaches like that. Esteban Real and Cochlear for instance, I worked on evolving a smaller network and then systematically expanding it to a larger one. Your elements are already there and scaling it up will just give you more power. So again, evolution gives you that starting point and then there's a mechanism that gives you the final result and a very powerful approach. But you could also simulate the actual growth process. And like I said before, evolving a starting point and then evolving or training the network, there's not that much work that's been done on that yet. We need some kind of a simulation environment so the interactions at will, the supervised environment doesn't really, it's not as easily usable here. Sorry, the interaction between neural networks? Yeah, the neural networks that you're creating, interacting with the world and learning from these sequences of interactions, perhaps communication with others. That's awesome. We would like to get there, but just the task of simulating something is at that level is very hard. It's very difficult. I love the idea. I mean, one of the powerful things about evolution on Earth is the predators and prey emerged. And like there's just like, there's bigger fish and smaller fish and it's fascinating to think that you could have neural networks competing against each other in one neural network being able to destroy another one. There's like wars of neural networks competing to solve the MNIST problem, I don't know. Yeah, yeah. Oh, totally, yeah, yeah, yeah. And we actually simulated also that prey and it was interesting what happened there, Padmini Rajagopalan did this and Kay Holkamp was a zoologist. So we had, again, we had simulated hyenas, simulated zebras. Nice. And initially, the hyenas just tried to hunt them and when they actually stumbled upon the zebra, they ate it and were happy. And then the zebras learned to escape and the hyenas learned to team up. And actually two of them approached in different directions. And now the zebras, their next step, they generated a behavior where they split in different directions, just like actually gazelles do when they are being hunted. They confuse the predator by going in different directions. That emerged and then more hyenas joined and kind of circled them. And then when they circled them, they could actually herd the zebras together and eat multiple zebras. So there was like an arms race of predators and prey. And they gradually developed more complex behaviors, some of which we actually do see in nature. And this kind of coevolution, that's competitive coevolution, it's a fascinating topic because there's a promise or possibility that you will discover something new that you don't already know. You didn't build it in. It came from this arms race. It's hard to keep the arms race going. It's hard to have rich enough simulation that supports all of these complex behaviors. But at least for several steps, we've already seen it in this predator prey scenario, yeah. First of all, it's fascinating to think about this context in terms of evolving architectures. So I've studied Tesla autopilot for a long time. It's one particular implementation of an AI system that's operating in the real world. I find it fascinating because of the scale at which it's used out in the real world. And I'm not sure if you're familiar with that system much, but, you know, Andre Kapathy leads that team on the machine learning side. And there's a multitask network, multiheaded network, where there's a core, but it's trained on particular tasks. And there's a bunch of different heads that are trained on that. Is there some lessons from evolutionary computation or neuroevolution that could be applied to this kind of multiheaded beast that's operating in the real world? Yes, it's a very good problem for neuroevolution. And the reason is that when you have multiple tasks, they support each other. So let's say you're learning to classify X ray images to different pathologies. So you have one task is to classify this disease and another one, this disease, another one, this one. And when you're learning from one disease, that forces certain kinds of internal representations and embeddings, and they can serve as a helpful starting point for the other tasks. So you are combining the wisdom of multiple tasks into these representations. And it turns out that you can do better in each of these tasks when you are learning simultaneously other tasks than you would by one task alone. Which is a fascinating idea in itself, yeah. Yes, and people do that all the time. I mean, you use knowledge of domains that you know in new domains, and certainly neural network can do that. When neuroevolution comes in is that, what's the best way to combine these tasks? Now there's architectural design that allow you to decide where and how the embeddings, the internal representations are combined and how much you combine them. And there's quite a bit of research on that. And my team, Elliot Meyerson has worked on that in particular, like what is a good internal representation that supports multiple tasks? And we're getting to understand how that's constructed and what's in it, so that it is in a space that supports multiple different heads, like you said. And that I think is fundamentally how biological intelligence works as well. You don't build a representation just for one task. You try to build something that's general, not only so that you can do better in one task or multiple tasks, but also future tasks and future challenges. So you learn the structure of the world and that helps you in all kinds of future challenges. And so you're trying to design a representation that will support an arbitrary set of tasks in a particular sort of class of problem. Yeah, and also it turns out, and that's again, a surprise that Elliot found was that those tasks don't have to be very related. You know, you can learn to do better vision by learning language or better language by learning about DNA structure. No, somehow the world. Yeah, it rhymes. The world rhymes, even if it's very disparate fields. I mean, on that small topic, let me ask you, because you've also on the competition neuroscience side, you worked on both language and vision. What's the connection between the two? What's more, maybe there's a bunch of ways to ask this, but what's more difficult to build from an engineering perspective and evolutionary perspective, the human language system or the human vision system or the equivalent of in the AI space language and vision, or is it the best as the multitask idea that you're speaking to that they need to be deeply integrated? Yeah, absolutely the latter. Learning both at the same time, I think is a fascinating direction in the future. So we have data sets where there's visual component as well as verbal descriptions, for instance, and that way you can learn a deeper representation, a more useful representation for both. But it's still an interesting question of which one is easier. I mean, recognizing objects or even understanding sentences, that's relatively possible, but where it becomes, where the challenges are is to understand the world. Like the visual world, the 3D, what are the objects doing and predicting what will happen, the relationships. That's what makes vision difficult. And language, obviously it's what is being said, what the meaning is. And the meaning doesn't stop at who did what to whom. There are goals and plans and themes, and you eventually have to understand the entire human society and history in order to understand the sentence very much fully. There are plenty of examples of those kinds of short sentences when you bring in all the world knowledge to understand it. And that's the big challenge. Now we are far from that, but even just bringing in the visual world together with the sentence will give you already a lot deeper understanding of what's happening. And I think that that's where we're going very soon. I mean, we've had ImageNet for a long time, and now we have all these text collections, but having both together and then learning a semantic understanding of what is happening, I think that that will be the next step in the next few years. Yeah, you're starting to see that with all the work with Transformers, was the community, the AI community starting to dip their toe into this idea of having language models that are now doing stuff with images, with vision, and then connecting the two. I mean, right now it's like these little explorations we're literally dipping the toe in, but maybe at some point we'll just dive into the pool and it'll just be all seen as the same thing. I do still wonder what's more fundamental, whether vision is, whether we don't think about vision correctly. Maybe the fact, because we're humans and we see things as beautiful and so on, and because we have cameras that are taking pixels as a 2D image, that we don't sufficiently think about vision as language. Maybe Chomsky is right all along, that vision is fundamental to, sorry, that language is fundamental to everything, to even cognition, to even consciousness. The base layer is all language, not necessarily like English, but some weird abstract representation, linguistic representation. Yeah, well, earlier we talked about the social structures and that may be what's underlying the language, and that's the more fundamental part, and then language has been added on top of that. Language emerges from the social interaction. Yeah, that's a very good guess. We are visual animals, though. A lot of the brain is dedicated to vision, and also, when we think about various abstract concepts, we usually reduce that to vision and images, and that's, you know, we go to a whiteboard, you draw pictures of very abstract concepts. So we tend to resort to that quite a bit, and that's a fundamental representation. It's probably possible that it predated language even. I mean, animals, a lot of, they don't talk, but they certainly do have vision, and language is interesting development in from mastication, from eating. You develop an organ that actually can produce sound to manipulate them. Maybe that was an accident. Maybe that was something that was available and then allowed us to do the communication, or maybe it was gestures. Sign language could have been the original proto language. We don't quite know, but the language is more fundamental than the medium in which it's communicated, and I think that it comes from those representations. Now, in current world, they are so strongly integrated, it's really hard to say which one is fundamental. You look at the brain structures and even visual cortex, which is supposed to be very much just vision. Well, if you are thinking of semantic concepts, you're thinking of language, visual cortex lights up. It's still useful, even for language computations. So there are common structures underlying them. So utilize what you need. And when you are understanding a scene, you're understanding relationships. Well, that's not so far from understanding relationships between words and concepts. So I think that that's how they are integrated. Yeah, and there's dreams, and once we close our eyes, there's still a world in there somehow operating and somehow possibly the visual system somehow integrated into all of it. I tend to enjoy thinking about aliens and thinking about the sad thing to me about extraterrestrial intelligent life, that if it visited us here on Earth, or if we came on Mars or maybe another solar system, another galaxy one day, that us humans would not be able to detect it or communicate with it or appreciate, like it'd be right in front of our nose and we were too self obsessed to see it. Not self obsessed, but our tools, our frameworks of thinking would not detect it. As a good movie, Arrival and so on, where Stephen Wolfram and his son, I think were part of developing this alien language of how aliens would communicate with humans. Do you ever think about that kind of stuff where if humans and aliens would be able to communicate with each other, like if we met each other at some, okay, we could do SETI, which is communicating from across a very big distance, but also just us, if you did a podcast with an alien, do you think we'd be able to find a common language and a common methodology of communication? I think from a computational perspective, the way to ask that is you have very fundamentally different creatures, agents that are created, would they be able to find a common language? Yes, I do think about that. I mean, I think a lot of people who are in computing, they, and AI in particular, they got into it because they were fascinated with science fiction and all of these options. I mean, Star Trek generated all kinds of devices that we have now, they envisioned it first and it's a great motivator to think about things like that. And I, so one, and again, being a computational scientist and trying to build intelligent agents, what I would like to do is have a simulation where the agents actually evolve communication, not just communication, we've done that, people have done that many times, that they communicate, they signal and so on, but actually develop a language. And language means grammar, it means all these social structures and on top of that, grammatical structures. And we do it under various conditions and actually try to identify what conditions are necessary for it to come out. And then we can start asking that kind of questions. Are those languages that emerge in those different simulated environments, are they understandable to us? Can we somehow make a translation? We can make it a concrete question. So machine translation of evolved languages. And so like languages that evolve come up with, can we translate, like I have a Google translate for the evolved languages. Yes, and if we do that enough, we have perhaps an idea what an alien language might be like, the space of where those languages can be. Because we can set up their environment differently. It doesn't need to be gravity. You can have all kinds of, societies can be different. They may have no predators. They may have all, everybody's a predator. All kinds of situations. And then see what the space possibly is where those languages are and what the difficulties are. That'd be really good actually to do that before the aliens come here. Yes, it's good practice. On the similar connection, you can think of AI systems as aliens. Is there ways to evolve a communication scheme for, there's a field you can call it explainable AI, for AI systems to be able to communicate. So you evolve a bunch of agents, but for some of them to be able to talk to you also. So to evolve a way for agents to be able to communicate about their world to us humans. Do you think that there's possible mechanisms for doing that? We can certainly try. And if it's an evolution competition system, for instance, you reward those solutions that are actually functional. That communication makes sense. It allows us to together again, achieve common goals. I think that's possible. But even from that paper that you mentioned, the anecdotes, it's quite likely also that the agents learn to lie and fake and do all kinds of things like that. I mean, we see that in even very low level, like bacterial evolution. There are cheaters. And who's to say that what they say is actually what they think. But that's what I'm saying, that there would have to be some common goal so that we can evaluate whether that communication is at least useful. They may be saying things just to make us feel good or get us to do what we want, but they would not turn them off or something. But so we would have to understand their internal representations much better to really make sure that that translation is critical. But it can be useful. And I think it's possible to do that. There are examples where visualizations are automatically created so that we can look into the system and that language is not that far from it. I mean, it is a way of communicating and logging what you're doing in some interpretable way. I think a fascinating topic, yeah, to do that. Yeah, you're making me realize that it's a good scientific question whether lying is an effective mechanism for integrating yourself and succeeding in a social network, in a world that is social. I tend to believe that honesty and love are evolutionary advantages in an environment where there's a network of intelligent agents. But it's also very possible that dishonesty and manipulation and even violence, all those kinds of things might be more beneficial. That's the old open question about good versus evil. But I tend to, I mean, I don't know if it's a hopeful, maybe I'm delusional, but it feels like karma is a thing, which is like long term, the agents, they're just kind to others sometimes for no reason will do better. In a society that's not highly constrained on resources. So like people start getting weird and evil towards each other and bad when the resources are very low relative to the needs of the populace, especially at the basic level, like survival, shelter, food, all those kinds of things. But I tend to believe that once you have those things established, then, well, not to believe, I guess I hope that AI systems will be honest. But it's scary to think about the Turing test, AI systems that will eventually pass the Turing test will be ones that are exceptionally good at lying. That's a terrifying concept. I mean, I don't know. First of all, sort of from somebody who studied language and obviously are not just a world expert in AI, but somebody who dreams about the future of the field. Do you hope, do you think there'll be human level or superhuman level intelligences in the future that we eventually build? Well, I definitely hope that we can get there. One, I think important perspective is that we are building AI to help us. That it is a tool like cars or language or communication, AI will help us be more productive. And that is always a condition. It's not something that we build and let run and it becomes an entity of its own that doesn't care about us. Now, of course, really find the future, maybe that might be possible, but not in the foreseeable future when we are building it. And therefore we always in a position of limiting what it can or cannot do. And your point about lying is very interesting. Even in these hyenas societies, for instance, when a number of these hyenas band together and they take a risk and steal the kill, there are always hyenas that hang back and don't participate in that risky behavior, but they walk in later and join the party after the kill. And there are even some that may be ineffective and cause others to have harm. So, and like I said, even bacteria cheat. And we see it in biology, there's always some element on opportunity. If you have a society, I think that is just because if you have a society, in order for society to be effective, you have to have this cooperation and you have to have trust. And if you have enough of agents who are able to trust each other, you can achieve a lot more. But if you have trust, you also have opportunity for cheaters and liars. And I don't think that's ever gonna go away. There will be hopefully a minority so that they don't get in the way. And we studied in these hyena simulations, like what the proportion needs to be before it is no longer functional. And you can point out that you can tolerate a few cheaters and a few liars and the society can still function. And that's probably going to happen when we build these systems at Autonomously Learn. The really successful ones are honest because that's the best way of getting things done. But there probably are also intelligent agents that find that they can achieve their goals by bending the rules or cheating. So that could be a huge benefit as opposed to having fixed AI systems. Say we build an AGI system and deploying millions of them, it'd be that are exactly the same. There might be a huge benefit to introducing sort of from like an evolution computation perspective, a lot of variation. Sort of like diversity in all its forms is beneficial even if some people are assholes or some robots are assholes. So like it's beneficial to have that because you can't always a priori know what's good, what's bad. But that's a fascinating. Absolutely. Diversity is the bread and butter. I mean, if you're running an evolution, you see diversity is the one fundamental thing you have to have. And absolutely, also, it's not always good diversity. It may be something that can be destructive. We had in these hyenas simulations, we have hyenas that just are suicidal. They just run and get killed. But they form the basis of those who actually are really fast, but stop before they get killed and eventually turn into this mob. So there might be something useful there if it's recombined with something else. So I think that as long as we can tolerate some of that, it may turn into something better. You may change the rules because it's so much more efficient to do something that was actually against the rules before. And we've seen society change over time quite a bit along those lines. That there were rules in society that we don't believe are fair anymore, even though they were considered proper behavior before. So things are changing. And I think that in that sense, I think it's a good idea to be able to tolerate some of that cheating because eventually we might turn into something better. So yeah, I think this is a message to the trolls and the assholes of the internet that you too have a beautiful purpose in this human ecosystem. So I appreciate you very much. In moderate quantities, yeah. In moderate quantities. So there's a whole field of artificial life. I don't know if you're connected to this field, if you pay attention. Is, do you think about this kind of thing? Is there impressive demonstration to you of artificial life? Do you think of the agency you work with in the evolutionary computation perspective as life? And where do you think this is headed? Like, is there interesting systems that we'll be creating more and more that make us redefine, maybe rethink about the nature of life? Different levels of definition and goals there. I mean, at some level, artificial life can be considered multiagent systems that build a society that again, achieves a goal. And it might be robots that go into a building and clean it up or after an earthquake or something. You can think of that as an artificial life problem in some sense. Or you can really think of it, artificial life, as a simulation of life and a tool to understand what life is and how life evolved on earth. And like I said, in artificial life conference, there are branches of that conference sessions of people who really worry about molecular designs and the start of life, like I said, primordial soup where eventually you get something self replicating. And they're really trying to build that. So it's a whole range of topics. And I think that artificial life is a great tool to understand life. And there are questions like sustainability, species, we're losing species. How bad is it? Is it natural? Is there a tipping point? And where are we going? I mean, like the hyena evolution, we may have understood that there's a pivotal point in their evolution. They discovered cooperation and coordination. Artificial life simulations can identify that and maybe encourage things like that. And also societies can be seen as a form of life itself. I mean, we're not talking about biological evolution, evolution of societies. Maybe some of the same phenomena emerge in that domain and having artificial life simulations and understanding could help us build better societies. Yeah, and thinking from a meme perspective of from Richard Dawkins, that maybe the organisms, ideas of the organisms, not the humans in these societies that from, it's almost like reframing what is exactly evolving. Maybe the interesting, the humans aren't the interesting thing as the contents of our minds is the interesting thing. And that's what's multiplying. And that's actually multiplying and evolving in a much faster timescale. And that maybe has more power on the trajectory of life on earth than does biological evolution is the evolution of these ideas. Yes, and it's fascinating, like I said before, that we can keep up somehow biologically. We evolved to a point where we can keep up with this meme evolution, literature, internet. We understand DNA and we understand fundamental particles. We didn't start that way a thousand years ago. And we haven't evolved biologically very much, but somehow our minds are able to extend. And therefore AI can be seen also as one such step that we created and it's our tool. And it's part of that meme evolution that we created, even if our biological evolution does not progress as fast. And us humans might only be able to understand so much. We're keeping up so far, or we think we're keeping up so far, but we might need AI systems to understand. Maybe like the physics of the universe is operating, look at strength theory. Maybe it's operating in much higher dimensions. Maybe we're totally, because of our cognitive limitations, are not able to truly internalize the way this world works. And so we're running up against the limitation of our own minds. And we have to create these next level organisms like AI systems that would be able to understand much deeper, like really understand what it means to live in a multi dimensional world that's outside of the four dimensions, the three of space and one of time. Translation, and generally we can deal with the world, even if you don't understand all the details, we can use computers, even though we don't, most of us don't know all the structure that's underneath or drive a car. I mean, there are many components, especially new cars that you don't quite fully know, but you have the interface, you have an abstraction of it that allows you to operate it and utilize it. And I think that that's perfectly adequate and we can build on it. And AI can play a similar role. I have to ask about beautiful artificial life systems or evolutionary computation systems. Cellular automata to me, I remember it was a game changer for me early on in life when I saw Conway's Game of Life who recently passed away, unfortunately. And it's beautiful how much complexity can emerge from such simple rules. I just don't, somehow that simplicity is such a powerful illustration and also humbling because it feels like I personally, from my perspective, understand almost nothing about this world because like my intuition fails completely how complexity can emerge from such simplicity. Like my intuition fails, I think, is the biggest problem I have. Do you find systems like that beautiful? Is there, do you think about cellular automata? Because cellular automata don't really have, and many other artificial life systems don't necessarily have an objective. Maybe that's a wrong way to say it. It's almost like it's just evolving and creating. And there's not even a good definition of what it means to create something complex and interesting and surprising, all those words that you said. Is there some of those systems that you find beautiful? Yeah, yeah. And similarly, evolution does not have a goal. It is responding to current situation and survival then creates more complexity and therefore we have something that we perceive as progress but that's not what evolution is inherently set to do. And yeah, that's really fascinating how a simple set of rules or simple mappings can, how from such simple mappings, complexity can emerge. So it's a question of emergence and self organization. And the game of life is one of the simplest ones and very visual and therefore it drives home the point that it's possible that nonlinear interactions and this kind of complexity can emerge from them. And biology and evolution is along the same lines. We have simple representations. DNA, if you really think of it, it's not that complex. It's a long sequence of them, there's lots of them but it's a very simple representation. And similarly with evolutionary computation, whatever string or tree representation we have and the operations, the amount of code that's required to manipulate those, it's really, really little. And of course, game of life even less. So how complexity emerges from such simple principles, that's absolutely fascinating. The challenge is to be able to control it and guide it and direct it so that it becomes useful. And like game of life is fascinating to look at and evolution, all the forms that come out is fascinating but can we actually make it useful for us? And efficient because if you actually think about each of the cells in the game of life as a living organism, there's a lot of death that has to happen to create anything interesting. And so I guess the question is for us humans that are mortal and then life ends quickly, we wanna kinda hurry up and make sure we take evolution, the trajectory that is a little bit more efficient than the alternatives. And that touches upon something we talked about earlier that evolution competition is very impatient. We have a goal, we want it right away whereas this biology has a lot of time and deep time and weak pressure and large populations. One great example of this is the novelty search. So evolutionary computation where you don't actually specify a fitness goal, something that is your actual thing that you want but you just reward solutions that are different from what you've seen before, nothing else. And you know what? You actually discover things that are interesting and useful that way. Ken Stanley and Joel Lehmann did this one study where they actually tried to evolve walking behavior on robots. And that's actually, we talked about earlier where your robot actually failed in all kinds of ways and eventually discovered something that was a very efficient walk. And it was because they rewarded things that were different that you were able to discover something. And I think that this is crucial because in order to be really different from what you already have, you have to utilize what is there in a domain to create something really different. So you have encoded the fundamentals of your world and then you make changes to those fundamentals you get further away. So that's probably what's happening in these systems of emergence. That the fundamentals are there. And when you follow those fundamentals you get into points and some of those are actually interesting and useful. Now, even in that robotic Walker simulation there was a large set of garbage, but among them, there were some of these gems. And then those are the ones that somehow you have to outside recognize and make useful. But this kind of productive systems if you code them the right kind of principles I think that encode the structure of the domain then you will get to these solutions and discoveries. It feels like that might also be a good way to live life. So let me ask, do you have advice for young people today about how to live life or how to succeed in their career or forget career, just succeed in life from an evolution and computation perspective? Yes, yes, definitely. Explore, diversity, exploration and individuals take classes in music, history, philosophy, math, engineering, see connections between them, travel, learn a language. I mean, all this diversity is fascinating and we have it at our fingertips today. It's possible, you have to make a bit of an effort because it's not easy, but the rewards are wonderful. Yeah, there's something interesting about an objective function of new experiences. So try to figure out, I mean, what is the maximally new experience I could have today? And that sort of that novelty, optimizing for novelty for some period of time might be very interesting way to sort of maximally expand the sets of experiences you had and then ground from that perspective, like what will be the most fulfilling trajectory through life. Of course, the flip side of that is where I come from. Again, maybe Russian, I don't know. But the choice has a detrimental effect, I think, at least from my mind where scarcity has an empowering effect. So if I sort of, if I have very little of something and only one of that something, I will appreciate it deeply until I came to Texas recently and I've been pigging out on delicious, incredible meat. I've been fasting a lot, so I need to do that again. But when you fast for a few days, that the first taste of a food is incredible. So the downside of exploration is that somehow, maybe you can correct me, but somehow you don't get to experience deeply any one of the particular moments, but that could be a psychology thing. That could be just a very human peculiar, flaw. Yeah, I didn't mean that you superficially explore. I mean, you can. Explore deeply. Yeah, so you don't have to explore 100 things, but maybe a few topics where you can take a deep enough dive that you gain an understanding. You yourself have to decide at some point that this is deep enough. And I obtained what I can from this topic and now it's time to move on. And that might take years. People sometimes switch careers and they may stay on some career for a decade and switch to another one. You can do it. You're not pretty determined to stay where you are, but in order to achieve something, 10,000 hours makes, you need 10,000 hours to become an expert on something. So you don't have to become an expert, but they even develop an understanding and gain the experience that you can use later. You probably have to spend, like I said, it's not easy. You've got to spend some effort on it. Now, also at some point then, when you have this diversity and you have these experiences, exploration, you may want to, you may find something that you can't stay away from. Like for us, it was computers, it was AI. It was, you know, that I just have to do it. And I, you know, and then it will take decades maybe and you are pursuing it because you figured out that this is really exciting and you can bring in your experiences. And there's nothing wrong with that either, but you asked what's the advice for young people. That's the exploration part. And then beyond that, after that exploration, you actually can focus and build a career. And, you know, even there you can switch multiple times, but I think that diversity exploration is fundamental to having a successful career as is concentration and spending an effort where it matters. And, but you are in better position to make the choice when you have done your homework. Explored. So exploration precedes commitment, but both are beautiful. Yeah. So again, from an evolutionary computation perspective, we'll look at all the agents that had to die in order to come up with different solutions in simulation. What do you think from that individual agent's perspective is the meaning of it all? So far as humans, you're just one agent who's going to be dead, unfortunately, one day too soon. What do you think is the why of why that agent came to be and eventually will be no more? Is there a meaning to it all? Yeah. In evolution, there is meaning. Everything is a potential direction. Everything is a potential stepping stone. Not all of them are going to work out. Some of them are foundations for further improvement. And even those that are perhaps going to die out were potential energies, potential solutions. In biology, we see a lot of species die off naturally. And you know, like the dinosaurs, I mean, they were really good solution for a while, but then it didn't turned out to be not such a good solution in the long term. When there's an environmental change, you have to have diversity. Some other solutions become better. Doesn't mean that that was an attempt. It didn't quite work out or last, but there are still dinosaurs among us, at least their relatives. And they may one day again be useful, who knows? So from an individual's perspective, you got to think of a bigger picture that it is a huge engine that is innovative. And these elements are all part of it, potential innovations on their own. And also as raw material perhaps, or stepping stones for other things that could come after. But it still feels from an individual perspective that I matter a lot. But even if I'm just a little cog in a giant machine, is that just a silly human notion in an individualistic society, no, she'll let go of that? Do you find beauty in being part of the giant machine? Yeah, I think it's meaningful. I think it adds purpose to your life that you are part of something bigger. That said, do you ponder your individual agent's mortality? Do you think about death? Do you fear death? Well, certainly more now than when I was a youngster and did skydiving and paragliding and all these things. You've become wiser. There is a reason for this life arc that younger folks are more fearless in many ways. That's part of the exploration. They are the individuals who think, hmm, I wonder what's over those mountains or what if I go really far in that ocean? What would I find? I mean, older folks don't necessarily think that way, but younger do and it's kind of counterintuitive. So yeah, but logically it's like, you have a limited amount of time, what can you do with it that matters? So you try to, you have done your exploration, you committed to a certain direction and you become an expert perhaps in it. What can I do that matters with the limited resources that I have? That's how I think a lot of people, myself included, start thinking later on in their career. And like you said, leave a bit of a trace and a bit of an impact even though after the agent is gone. Yeah, that's the goal. Well, this was a fascinating conversation. I don't think there's a better way to end it. Thank you so much. So first of all, I'm very inspired of how vibrant the community at UT Austin and Austin is. It's really exciting for me to see it. And this whole field seems like profound philosophically, but also the path forward for the artificial intelligence community. So thank you so much for explaining so many cool things to me today and for wasting all of your valuable time with me. Oh, it was a pleasure. Thanks. I appreciate it. Thanks for listening to this conversation with Risto McAlignan. And thank you to the Jordan Harbinger Show, Grammarly, Belcampo, and Indeed. Check them out in the description to support this podcast. And now let me leave you with some words from Carl Sagan. Extinction is the rule. Survival is the exception. Thank you for listening. I hope to see you next time. And yes, the communication is multifaceted. I mean, they vocalize and call for friends, but they also rub against each other and they push and they do all kinds of gestures and so on. So they don't act alone. And I don't think people act alone very much either, at least normal, most of the time. And social systems are so strong for humans that I think we build everything on top of these kinds of structures. And one interesting theory around that, bigotness theory, for instance, for language, but language origins is that where did language come from? And it's a plausible theory that first came social systems, that you have different roles in a society. And then those roles are exchangeable, that I scratch your back, you scratch my back, we can exchange roles. And once you have the brain structures that allow you to understand actions in terms of roles that can be changed, that's the basis for language, for grammar. And now you can start using symbols to refer to objects in the world. And you have this flexible structure. So there's a social structure that's fundamental for language to develop. Now, again, then you have language, you can refer to things that are not here right now. And that allows you to then build all the good stuff about planning, for instance, and building things and so on. So yeah, I think that very strongly humans are social and that gives us ability to structure the world. But also as a society, we can do so much more because one person does not have to do everything. You can have different roles and together achieve a lot more. And that's also something we see in computational simulations today. I mean, we have multi agent systems that can perform tasks. This fascinating demonstration, Marco Dorego, I think it was, these little robots that had to navigate through an environment and there were things that are dangerous, like maybe a big chasm or some kind of groove, a hole, and they could not get across it. But if they grab each other with their gripper, they formed a robot that was much longer under the team and this way they could get across that. So this is a great example of how together we can achieve things we couldn't otherwise. Like the hyenas, you know, alone they couldn't, but as a team they could. And I think humans do that all the time. We're really good at that. Yeah, and the way you described the system of hyenas, it almost sounds algorithmic. Like the problem with humans is they're so complex, it's hard to think of them as algorithms. But with hyenas, there's a, it's simple enough to where it feels like, at least hopeful that it's possible to create computational systems that mimic that. Yeah, that's exactly why we looked at that. As opposed to humans. Like I said, they are intelligent, but they are not quite as intelligent as say, baboons, which would learn a lot and would be much more flexible. The hyenas are relatively rigid in what they can do. And therefore you could look at this behavior, like this is a breakthrough in evolution about to happen. That they've discovered something about social structures, communication, about cooperation, and it might then spill over to other things too in thousands of years in the future. Yeah, I think the problem with baboons and humans is probably too much is going on inside the head. We won't be able to measure it if we're observing the system. With hyenas, it's probably easier to observe the actual decision making and the various motivations that are involved. Yeah, they are visible. And we can even quantify possibly their emotional state because they leave droppings behind. And there are chemicals there that can be associated with neurotransmitters. And we can separate what emotions they might have experienced in the last 24 hours. Yeah. What to you is the most beautiful, speaking of hyenas, what to you is the most beautiful nature inspired algorithm in your work that you've come across? Something maybe early on in your work or maybe today? I think evolution computation is the most amazing method. So what fascinates me most is that with computers is that you can get more out than you put in. I mean, you can write a piece of code and your machine does what you told it. I mean, this happened to me in my freshman year. It did something very simple and I was just amazed. I was blown away that it would get the number and it would compute the result. And I didn't have to do it myself. Very simple. But if you push that a little further, you can have machines that learn and they might learn patterns. And already say deep learning neural networks, they can learn to recognize objects, sounds, patterns that humans have trouble with. And sometimes they do it better than humans. And that's so fascinating. And now if you take that one more step, you get something like evolutionary algorithms that discover things, they create things, they come up with solutions that you did not think of. And that just blows me away. It's so great that we can build systems, algorithms that can be in some sense smarter than we are, that they can discover solutions that we might miss. A lot of times it is because we have as humans, we have certain biases, we expect the solutions to be certain way and you don't put those biases into the algorithm so they are more free to explore. And evolution is just absolutely fantastic explorer. And that's what really is fascinating. Yeah, I think I get made fun of a bit because I currently don't have any kids, but you mentioned programs. I mean, do you have kids? Yeah. So maybe you could speak to this, but there's a magic to the creative process. Like with Spot, the Boston Dynamics Spot, but really any robot that I've ever worked on, it just feels like the similar kind of joy I imagine I would have as a father. Not the same perhaps level, but like the same kind of wonderment. Like there's exactly this, which is like you know what you had to do initially to get this thing going. Let's speak on the computer science side, like what the program looks like, but something about it doing more than what the program was written on paper is like that somehow connects to the magic of this entire universe. Like that's like, I feel like I found God. Every time I like, it's like, because you've really created something that's living. Yeah. Even if it's a simple program. It has a life of its own, it has the intelligence of its own. It's beyond what you actually thought. Yeah. And that is, I think it's exactly spot on. That's exactly what it's about. You created something and it has a ability to live its life and do good things and you just gave it a starting point. So in that sense, I think it's, that may be part of the joy actually. But you mentioned creativity in this context, especially in the context of evolutionary computation. So, we don't often think of algorithms as creative. So how do you think about creativity? Yeah, algorithms absolutely can be creative. They can come up with solutions that you don't think about. I mean, creativity can be defined. A couple of requirements has to be new. It has to be useful and it has to be surprising. And those certainly are true with, say, evolutionary computation discovering solutions. So maybe an example, for instance, we did this collaboration with MIT Media Lab, Caleb Harbus Lab, where they had a hydroponic food computer, they called it, environment that was completely computer controlled, nutrients, water, light, temperature, everything is controlled. Now, what do you do if you can control everything? Farmers know a lot about how to make plants grow in their own patch of land. But if you can control everything, it's too much. And it turns out that we don't actually know very much about it. So we built a system, evolutionary optimization system, together with a surrogate model of how plants grow and let this system explore recipes on its own. And initially, we were focusing on light, how strong, what wavelengths, how long the light was on. And we put some boundaries which we thought were reasonable. For instance, that there was at least six hours of darkness, like night, because that's what we have in the world. And very quickly, the system, evolution, pushed all the recipes to that limit. We were trying to grow basil. And we initially had some 200, 300 recipes, exploration as well as known recipes. But now we are going beyond that. And everything was pushed to that limit. So we look at it and say, well, we can easily just change it. Let's have it your way. And it turns out the system discovered that basil does not need to sleep. 24 hours, lights on, and it will thrive. It will be bigger, it will be tastier. And this was a big surprise, not just to us, but also the biologists in the team that anticipated that there are some constraints that are in the world for a reason. It turns out that evolution did not have the same bias. And therefore, it discovered something that was creative. It was surprising, it was useful, and it was new. That's fascinating to think about the things we think that are fundamental to living systems on Earth today, whether they're actually fundamental or they somehow fit the constraints of the system. And all we have to do is just remove the constraints. Do you ever think about, I don't know how much you know about brain computer interfaces in your link. The idea there is our brains are very limited. And if we just allow, we plug in, we provide a mechanism for a computer to speak with the brain. So you're thereby expanding the computational power of the brain. The possibilities there, from a very high level philosophical perspective, is limitless. But I wonder how limitless it is. Are the constraints we have features that are fundamental to our intelligence? Or is this just this weird constraint in terms of our brain size and skull and lifespan and senses? It's just the weird little quirk of evolution. And if we just open that up, like add much more senses, add much more computational power, the intelligence will expand exponentially. Do you have a sense about constraints, the relationship of evolution and computation to the constraints of the environment? Well, at first I'd like to comment on that, like changing the inputs to human brain. And flexibility of the brain. I think there's a lot of that. There are experiments that are done in animals like Mikangazuru at MIT, switching the auditory and visual information and going to the wrong part of the cortex. And the animal was still able to hear and perceive the visual environment. And there are kids that are born with severe disorders and sometimes they have to remove half of the brain, like one half, and they still grow up. They have the functions migrate to the other parts. There's a lot of flexibility like that. So I think it's quite possible to hook up the brain with different kinds of sensors, for instance, and something that we don't even quite understand or have today on different kinds of wavelengths or whatever they are. And then the brain can learn to make sense of it. And that I think is this good hope that these prosthetic devices, for instance, work, not because we make them so good and so easy to use, but the brain adapts to them and can learn to take advantage of them. And so in that sense, if there's a trouble, a problem, I think the brain can be used to correct it. Now going beyond what we have today, can you get smarter? That's really much harder to do. Giving the brain more input probably might overwhelm it. It would have to learn to filter it and focus and in order to use the information effectively and augmenting intelligence with some kind of external devices like that might be difficult, I think. But replacing what's lost, I think is quite possible. Right, so our intuition allows us to sort of imagine that we can replace what's been lost, but expansion beyond what we have, I mean, we're already one of the most, if not the most intelligent things on this earth, right? So it's hard to imagine. But if the brain can hold up with an order of magnitude greater set of information thrown at it, if it can do, if it can reason through that. Part of me, this is the Russian thing, I think, is I tend to think that the limitations is where the superpower is, that immortality and a huge increase in bandwidth of information by connecting computers with the brain is not going to produce greater intelligence. It might produce lesser intelligence. So I don't know, there's something about the scarcity being essential to fitness or performance, but that could be just because we're so limited. No, exactly, you make do with what you have, but you don't have to be a genius but you don't have to pipe it directly to the brain. I mean, we already have devices like phones where we can look up information at any point. And that can make us more productive. You don't have to argue about, I don't know, what happened in that baseball game or whatever it is, because you can look it up right away. And I think in that sense, we can learn to utilize tools. And that's what we have been doing for a long, long time. And we are already, the brain is already drinking the water, firehose, like vision. There's way more information in vision that we actually process. So brain is already good at identifying what matters. And that we can switch that from vision to some other wavelength or some other kind of modality. But I think that the same processing principles probably still apply. But also indeed this ability to have information more accessible and more relevant, I think can enhance what we do. I mean, kids today at school, they learn about DNA. I mean, things that were discovered just a couple of years ago. And it's already common knowledge and we are building on it. And we don't see a problem where there's too much information that we can absorb and learn. Maybe people become a little bit more narrow in what they know, they are in one field. But this information that we have accumulated, it is passed on and people are picking up on it and they are building on it. So it's not like we have reached the point of saturation. We have still this process that allows us to be selective and decide what's interesting, I think still works even with the more information we have today. Yeah, it's fascinating to think about like Wikipedia becoming a sensor. Like, so the fire hose of information from Wikipedia. So it's like you integrated directly into the brain to where you're thinking, like you're observing the world with all of Wikipedia directly piping into your brain. So like when I see a light, I immediately have like the history of who invented electricity, like integrated very quickly into. So just the way you think about the world might be very interesting if you can integrate that kind of information. What are your thoughts, if I could ask on early steps on the Neuralink side? I don't know if you got a chance to see, but there was a monkey playing pong through the brain computer interface. And the dream there is sort of, you're already replacing the thumbs essentially that you would use to play video game. The dream is to be able to increase further the interface by which you interact with the computer. Are you impressed by this? Are you worried about this? What are your thoughts as a human? I think it's wonderful. I think it's great that we could do something like that. I mean, there are devices that read your EEG for instance, and humans can learn to control things using just their thoughts in that sense. And I don't think it's that different. I mean, those signals would go to limbs, they would go to thumbs. Now the same signals go through a sensor to some computing system. It still probably has to be built on human terms, not to overwhelm them, but utilize what's there and sense the right kind of patterns that are easy to generate. But, oh, that I think is really quite possible and wonderful and could be very much more efficient. Is there, so you mentioned surprising being a characteristic of creativity. Is there something, you already mentioned a few examples, but is there something that jumps out at you as was particularly surprising from the various evolutionary computation systems you've worked on, the solutions that were come up along the way? Not necessarily the final solutions, but maybe things that would even discarded. Is there something that just jumps to mind? It happens all the time. I mean, evolution is so creative, so good at discovering solutions you don't anticipate. A lot of times they are taking advantage of something that you didn't think was there, like a bug in the software, for instance. A lot of, there's a great paper, the community put it together about surprising anecdotes about evolutionary computation. A lot of them are indeed, in some software environment, there was a loophole or a bug and the system utilizes that. By the way, for people who want to read it, it's kind of fun to read. It's called The Surprising Creativity of Digital Evolution, a collection of anecdotes from the evolutionary computation and artificial life research communities. And there's just a bunch of stories from all the seminal figures in this community. You have a story in there that released to you, at least on the Tic Tac Toe memory bomb. So can you, I guess, describe that situation if you think that's still? Yeah, that's a quite a bit smaller scale than our basic doesn't need to sleep surprise, but it was actually done by students in my class, in a neural nets evolution computation class. There was an assignment. It was perhaps a final project where people built game playing AI, it was an AI class. And this one, and it was for Tic Tac Toe or five in a row in a large board. And this one team evolved a neural network to make these moves. And they set it up, the evolution. They didn't really know what would come out, but it turned out that they did really well. Evolution actually won the tournament. And most of the time when it won, it won because the other teams crashed. And then when we look at it, like what was going on was that evolution discovered that if it makes a move that's really, really far away, like millions of squares away, the other teams, the other programs has expanded memory in order to take that into account until they run out of memory and crashed. And then you win a tournament by crashing all your opponents. I think that's quite a profound example, which probably applies to most games, from even a game theoretic perspective, that sometimes to win, you don't have to be better within the rules of the game. You have to come up with ways to break your opponent's brain, if it's a human, like not through violence, but through some hack where the brain just is not, you're basically, how would you put it? You're going outside the constraints of where the brain is able to function. Expectations of your opponent. I mean, this was even Kasparov pointed that out that when Deep Blue was playing against Kasparov, that it was not playing the same way as Kasparov expected. And this has to do with not having the same biases. And that's really one of the strengths of the AI approach. Can you at a high level say, what are the basic mechanisms of evolutionary computation algorithms that use something that could be called an evolutionary approach? Like how does it work? What are the connections to the, what are the echoes of the connection to his biological? A lot of these algorithms really do take motivation from biology, but they are caricatures. You try to essentialize it and take the elements that you believe matter. So in evolutionary computation, it is the creation of variation and then the selection upon that. So the creation of variation, you have to have some mechanism that allow you to create new individuals that are very different from what you already have. That's the creativity part. And then you have to have some way of measuring how well they are doing and using that measure to select who goes to the next generation and you continue. So first you also, you have to have some kind of digital representation of an individual that can be then modified. So I guess humans in biological systems have DNA and all those kinds of things. And so you have to have similar kind of encodings in a computer program. Yes, and that is a big question. How do you encode these individuals? So there's a genotype, which is that encoding and then a decoding mechanism gives you the phenotype, which is the actual individual that then performs the task and in an environment can be evaluated how good it is. So even that mapping is a big question and how do you do it? But typically the representations are, either they are strings of numbers or they are some kind of trees. Those are something that we know very well in computer science and we try to do that. But they, and DNA in some sense is also a sequence and it's a string. So it's not that far from it, but DNA also has many other aspects that we don't take into account necessarily like there's folding and interactions that are other than just the sequence itself. And lots of that is not yet captured and we don't know whether they are really crucial. Evolution, biological evolution has produced wonderful things, but if you look at them, it's not necessarily the case that every piece is irreplaceable and essential. There's a lot of baggage because you have to construct it and it has to go through various stages and we still have appendix and we have tail bones and things like that that are not really that useful. If you try to explain them now, it would make no sense, very hard. But if you think of us as productive evolution, you can see where they came from. They were useful at one point perhaps and no longer are, but they're still there. So that process is complex and your representation should support it. And that is quite difficult if we are limited with strings or trees, and then we are pretty much limited what can be constructed. And one thing that we are still missing in evolutionary computation in particular is what we saw in biology, major transitions. So that you go from, for instance, single cell to multi cell organisms and eventually societies. There are transitions of level of selection and level of what a unit is. And that's something we haven't captured in evolutionary computation yet. Does that require a dramatic expansion of the representation? Is that what that is? Most likely it does, but it's quite, we don't even understand it in biology very well where it's coming from. So it would be really good to look at major transitions in biology, try to characterize them a little bit more in detail, what the processes are. How does a, so like a unit, a cell is no longer evaluated alone. It's evaluated as part of a community, a multi cell organism. Even though it could reproduce, now it can't alone. It has to have that environment. So there's a push to another level, at least a selection. And how do you make that jump to the next level? Yes, how do you make the jump? As part of the algorithm. Yeah, yeah. So we haven't really seen that in computation yet. And there are certainly attempts to have open ended evolution. Things that could add more complexity and start selecting at a higher level. But it is still not quite the same as going from single to multi to society, for instance, in biology. So there essentially would be, as opposed to having one agent, those agent all of a sudden spontaneously decide to then be together. And then your entire system would then be treating them as one agent. Something like that. Some kind of weird merger building. But also, so you mentioned, I think you mentioned selection. So basically there's an agent and they don't get to live on if they don't do well. So there's some kind of measure of what doing well is and isn't. And does mutation come into play at all in the process and what in the world does it serve? Yeah, so, and again, back to what the computational mechanisms of evolution computation are. So the way to create variation, you can take multiple individuals, two usually, but you could do more. And you exchange the parts of the representation. You do some kind of recombination. Could be crossover, for instance. In biology, you do have DNA strings that are cut and put together again. We could do something like that. And it seems to be that in biology, the crossover is really the workhorse in biological evolution. In computation, we tend to rely more on mutation. And that is making random changes into parts of the chromosome. You can try to be intelligent and target certain areas of it and make the mutations also follow some principle. Like you collect statistics of performance and correlations and try to make mutations you believe are going to be helpful. That's where evolution computation has moved in the last 20 years. I mean, evolution computation has been around for 50 years, but a lot of the recent... Success comes from mutation. Yes, comes from using statistics. It's like the rest of machine learning based on statistics. We use similar tools to guide evolution computation. And in that sense, it has diverged a bit from biological evolution. And that's one of the things I think we could look at again, having a weaker selection, more crossover, large populations, more time, and maybe a different kind of creativity would come out of it. We are very impatient in evolution computation today. We want answers right now, right, quickly. And if somebody doesn't perform, kill it. And biological evolution doesn't work quite that way. And it's more patient. Yes, much more patient. So I guess we need to add some kind of mating, some kind of like dating mechanisms, like marriage maybe in there. So into our algorithms to improve the combination as opposed to all mutation doing all of the work. Yeah, and many ways of being successful. Usually in evolution computation, we have one goal, play this game really well compared to others. But in biology, there are many ways of being successful. You can build niches. You can be stronger, faster, larger, or smarter, or eat this or eat that. So there are many ways to solve the same problem of survival. And that then breeds creativity. And it allows more exploration. And eventually you get solutions that are perhaps more creative rather than trying to go from initial population directly or more or less directly to your maximum fitness, which you measure as just one metric. So in a broad sense, before we talk about neuroevolution, do you see evolutionary computation as more effective than deep learning in a certain context? Machine learning, broadly speaking. Maybe even supervised machine learning. I don't know if you want to draw any kind of lines and distinctions and borders where they rub up against each other kind of thing, where one is more effective than the other in the current state of things. Yes, of course, they are very different and they address different kinds of problems. And the deep learning has been really successful in domains where we have a lot of data. And that means not just data about situations, but also what the right answers were. So labeled examples, or they might be predictions, maybe weather prediction where the data itself becomes labels. What happened, what the weather was today and what it will be tomorrow. So they are very effective deep learning methods on that kind of tasks. But there are other kinds of tasks where we don't really know what the right answer is. Game playing, for instance, but many robotics tasks and actions in the world, decision making and actual practical applications, like treatments and healthcare or investment in stock market. Many tasks are like that. We don't know and we'll never know what the optimal answers were. And there you need different kinds of approach. Reinforcement learning is one of those. Reinforcement learning comes from biology as well. Agents learn during their lifetime. They eat berries and sometimes they get sick and then they don't and get stronger. And then that's how you learn. And evolution is also a mechanism like that at a different timescale because you have a population, not an individual during his lifetime, but an entire population as a whole can discover what works. And there you can afford individuals that don't work out. They will, you know, everybody dies and you have a next generation and they will be better than the previous one. So that's the big difference between these methods. They apply to different kinds of problems. And in particular, there's often a comparison that's kind of interesting and important between reinforcement learning and evolutionary computation. And initially, reinforcement learning was about individual learning during their lifetime. And evolution is more engineering. You don't care about the lifetime. You don't care about all the individuals that are tested. You only care about the final result. The last one, the best candidate that evolution produced. In that sense, they also apply to different kinds of problems. And now that boundary is starting to blur a bit. You can use evolution as an online method and reinforcement learning to create engineering solutions, but that's still roughly the distinction. And from the point of view of what algorithm you wanna use, if you have something where there is a cost for every trial, reinforcement learning might be your choice. Now, if you have a domain where you can use a surrogate perhaps, so you don't have much of a cost for trial, and you want to have surprises, you want to explore more broadly, then this population based method is perhaps a better choice because you can try things out that you wouldn't afford when you're doing reinforcement learning. There's very few things as entertaining as watching either evolutionary computation or reinforcement learning teaching a simulated robot to walk. Maybe there's a higher level question that could be asked here, but do you find this whole space of applications in the robotics interesting for evolution computation? Yeah, yeah, very much. And indeed, there are fascinating videos of that. And that's actually one of the examples where you can contrast the difference. Between reinforcement learning and evolution. Yes, so if you have a reinforcement learning agent, it tries to be conservative because it wants to walk as long as possible and be stable. But if you have evolutionary computation, it can afford these agents that go haywire. They fall flat on their face and they could take a step and then they jump and then again fall flat. And eventually what comes out of that is something like a falling that's controlled. You take another step and another step and you no longer fall. Instead you run, you go fast. So that's a way of discovering something that's hard to discover step by step incrementally. Because you can afford these evolutionist dead ends, although they are not entirely dead ends in the sense that they can serve as stepping stones. When you take two of those, put them together, you get something that works even better. And that is a great example of this kind of discovery. Yeah, learning to walk is fascinating. I talked quite a bit to Russ Tedrick who's at MIT. There's a community of folks who just roboticists who love the elegance and beauty of movement. And walking bipedal robotics is beautiful, but also exceptionally dangerous in the sense that like you're constantly falling essentially if you want to do elegant movement. And the discovery of that is, I mean, it's such a good example of that the discovery of a good solution sometimes requires a leap of faith and patience and all those kinds of things. I wonder what other spaces where you have to discover those kinds of things in. Yeah, another interesting direction is learning for virtual creatures, learning to walk. We did a study in simulation, obviously, that you create those creatures, not just their controller, but also their body. So you have cylinders, you have muscles, you have joints and sensors, and you're creating creatures that look quite different. Some of them have multiple legs. Some of them have no legs at all. And then the goal was to get them to move, to walk, to run. And what was interesting is that when you evolve the controller together with the body, you get movements that look natural because they're optimized for that physical setup. And these creatures, you start believing them that they're alive because they walk in a way that you would expect somebody with that kind of a setup to walk. Yeah, there's something subjective also about that, right? I've been thinking a lot about that, especially in the human robot interaction context. You know, I mentioned Spot, the Boston Dynamics robot. There is something about human robot communication. Let's say, let's put it in another context, something about human and dog context, like a living dog, where there's a dance of communication. First of all, the eyes, you both look at the same thing and the dogs communicate with their eyes as well. Like if you're a human, if you and a dog want to deal with a particular object, you will look at the person, the dog will look at you and then look at the object and look back at you, all those kinds of things. But there's also just the elegance of movement. I mean, there's the, of course, the tail and all those kinds of mechanisms of communication and it all seems natural and often joyful. And for robots to communicate that, it's really difficult how to figure that out because it's almost seems impossible to hard code in. You can hard code it for demo purpose or something like that, but it's essentially choreographed. Like if you watch some of the Boston Dynamics videos where they're dancing, all of that is choreographed by human beings. But to learn how to, with your movement, demonstrate a naturalness and elegance, that's fascinating. Of course, in the physical space, that's very difficult to do to learn the kind of scale that you're referring to, but the hope is that you could do that in simulation and then transfer it into the physical space if you're able to model the robot sufficiently naturally. Yeah, and sometimes I think that that requires a theory of mind on the side of the robot that they understand what you're doing because they themselves are doing something similar. And that's a big question too. We talked about intelligence in general and the social aspect of intelligence. And I think that's what is required that we humans understand other humans because we assume that they are similar to us. We have one simulation we did a while ago. Ken Stanley did that. Two robots that were competing simulation, like I said, they were foraging for food to gain energy. And then when they were really strong, they would bounce into the other robot and win if they were stronger. And we watched evolution discover more and more complex behaviors. They first went to the nearest food and then they started to plot a trajectory so they get more, but then they started to pay attention what the other robot was doing. And in the end, there was a behavior where one of the robots, the most sophisticated one, sensed where the food pieces were and identified that the other robot was close to two of a very far distance and there was one more food nearby. So it faked, now I'm using anthropomorphizing terms, but it made a move towards those other pieces in order for the other robot to actually go and get them because it knew that the last remaining piece of food was close and the other robot would have to travel a long way, lose its energy and then lose the whole competition. So there was like emergence of something like a theory of mind, knowing what the other robot would do, to guide it towards bad behavior in order to win. So we can get things like that happen in simulation as well. But that's a complete natural emergence of a theory of mind. But I feel like if you add a little bit of a place for a theory of mind to emerge like easier, then you can go really far. I mean, some of these things with evolution, you know, you add a little bit of design in there, it'll really help. And I tend to think that a very simple theory of mind will go a really long way for cooperation between agents and certainly for human robot interaction. Like it doesn't have to be super complicated.

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