HUMAN LANGUAGE AND EVOLUTION Shigeru Miyagawa MITUTokyo June

HUMAN LANGUAGE AND EVOLUTION Shigeru Miyagawa MIT/UTokyo June 1, 2018

Puzzles, puzzles…. Darwin’s Puzzle: Natural selection caused species to change continuously; slow accumulation of gradual change eventually produced new species Human language and the accompanying high cognitive capabilities – AN EXCEPTION? "the difference between the mind of the lowest man and that of the highest animal is immense" (Darwin 1871: 100) S Miyagawa June 2018 2

Wallace’s Puzzle (Alfred Wallace, 1870) Evolution should have endowed the humans with a brain a little better than that of an ape, yet what we ended up with is far more powerful than what a gradual evolutionary adaption would predict. Development of human high cognitive capability, including language, is not consistent with the idea of fitness — music, art, religion. S Miyagawa June 2018 3

Chomsky’s Puzzle (e. g. , Chomsky 2016) Language arose rapidly possibly due to some minor genetic mutation. Competing view: Gradual: one word, two words, . . . (Jackendoff, etc. ) Darwin’s theory translated to modern theory of genetics (Klein 1989): Evolution can be defined as change in gene frequencies through time — Darwin’s “descent with modification” Fitness Gradual (assumes language gives advantage to the offspring) Mutation Rapid S Miyagawa June 2018 4

We are so human-centric! -Haruki Murakami, 1 Q 84 Human beings are ultimately nothing but carriers — passageways—for genes. They ride us into the ground like racehorses from generation to generation. Genes don’t think about what constitutes good or evil. They don’t care whether we are happy or unhappy. We’re just means to an end for them. The only thing they think about is what is most efficient for them. S Miyagawa June 2018 5

In 1866, Linguistic Society of Paris banned all debate about evolution of language. S Miyagawa June 2018 6

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WHY DID THE BRAIN GROW? S Miyagawa June 2018 10

In the last 20, 000 years: -13% S Miyagawa June 2018 11

WHY DID THE BRAIN SHRINK? S Miyagawa June 2018 12

To try to get at when language arose in evolution, we can only look at indirect evidence because LANGUAGE DOESN’T FOSSILIZE S Miyagawa June 2018 13

TOOLS S Miyagawa June 2018 14

2. 5 million years ago 3. 3 million years ago Acheulean handaxe Core preparation S Miyagawa June 2018 15

100, 000 YEARS AGO S Miyagawa June 2018 16

Ochre and the age of human language Arose about 75, 000 - 100, 000 years ago (Tattersall, 2009) Blombos Cave, S. Africa 75, 000 years ago Evolutionary Studies Institute University of the Witwatersrand S Miyagawa June 2018 17