Evolution is a stochastic process operating almost entirely in the shadowy past, so the scientifically-responsible answer to this “why?” question is “we don’t know for sure”, I think we can all agree.
Moving past that to speculate though, I think Chomsky would point to two (surely somewhat syncretic) forces:
1. Evolution is not an exhaustive breadth-first search; even if an adaption would be advantageous, genetic affordances can make it unlikely on a finite timeline. Theres lots of speculation on why humans in particular were well-prepared to evolve language for internal deliberation and/or external communication, but it’s somewhat beside the point here.
2. Evolution works most quickly in reaction to environmental stressors. There’s something of a consensus forming around the importance of changing climates for our genus (i.e. why aren't there other apes in cold regions?), whereas birds were inherently afforded a much simpler answer to that stressor: migration.
All of that said, I think it’s important to highlight an under-appreciated fact: the only things we have ever observed using language are a) humans, b) possibly other Homo species like Homo Naledi, c) LLMs, and—as of the past ~week (!!!)—D) possibly Bonobos.
Lots of animals communicate using words/signs, and a majority (?) of plant & animal species signal to each other and others using scents, colors, shapes, body language, etc. But only the above four can intuitively synthesize those signs on the fly into contextual phrases — or, as Chomsky would say, “generate an infinite range of output from a finite range of inputs”.
It’s worth caveating that this is absolutely a subjective stance based on how you want to use “language”, and that a sizeable camp of linguists would disagree on that basis. But I think the underlying unique quality is important, so Chomsky is correct to single it out as “language” — otherwise, how would you even phrase the above question? Birds clearly have complex verbal and visual communication already, and “better communication” is vague and unsatisfying, IMHO.
What I think lends strength to Chomsky's theory is that is virtually, informally a corollary of computational complexity theory (grammars, P = NP, and related ideas) which was a direct consequence of Alan Turing.
So for the camp of linguists that disagree I do wonder what alternative theoretical foundation do they have.
Moving past that to speculate though, I think Chomsky would point to two (surely somewhat syncretic) forces:
1. Evolution is not an exhaustive breadth-first search; even if an adaption would be advantageous, genetic affordances can make it unlikely on a finite timeline. Theres lots of speculation on why humans in particular were well-prepared to evolve language for internal deliberation and/or external communication, but it’s somewhat beside the point here.
2. Evolution works most quickly in reaction to environmental stressors. There’s something of a consensus forming around the importance of changing climates for our genus (i.e. why aren't there other apes in cold regions?), whereas birds were inherently afforded a much simpler answer to that stressor: migration.
All of that said, I think it’s important to highlight an under-appreciated fact: the only things we have ever observed using language are a) humans, b) possibly other Homo species like Homo Naledi, c) LLMs, and—as of the past ~week (!!!)—D) possibly Bonobos.
Lots of animals communicate using words/signs, and a majority (?) of plant & animal species signal to each other and others using scents, colors, shapes, body language, etc. But only the above four can intuitively synthesize those signs on the fly into contextual phrases — or, as Chomsky would say, “generate an infinite range of output from a finite range of inputs”.
It’s worth caveating that this is absolutely a subjective stance based on how you want to use “language”, and that a sizeable camp of linguists would disagree on that basis. But I think the underlying unique quality is important, so Chomsky is correct to single it out as “language” — otherwise, how would you even phrase the above question? Birds clearly have complex verbal and visual communication already, and “better communication” is vague and unsatisfying, IMHO.