If you believe that speech is a survival skill (which I would think most people believe) then anything that increases its prevalence or effectiveness would be evolutionarily selected for, right? We’re talking a 300-500+ Ky period, probably almost 2X that (depending upon the speech capabilities of our hominid ancestors), so plenty of time for evolutionary pressure to apply.
I don't think that's at all likely. We've had fire and had the physiological adaptations enabling speech for well over a million years. We've been manufacturing complex tools such as spears with stone tips for about half a million years, to Homo heidelbergensis. Even Ergaster had lifespans allowing survival to an age where grandchildren could reach adulthood, allowing for skills transfer.
You're probably on to something there. Hundreds of millions of years of evolution for finding food and avoiding predators. At best: a few thousand for managing linguistic skills. (or possibly hundreds of thousands, when it comes to our ancestor's pre-linguistic abilities).
Well, I think we have next to no information about language development for 195,000 of those 200,000 years, so we don't a much reason to believe anything.
I'd speculate that since language skills are important, evolution would have worked to increase them over that era.
This is a good point. I think this can (partly) be explained by the significance of language in the evolution human communities. We can imagine how speech impediments might have a negative correlation with survivability, on both the individual and group levels. I imagine groups with good communication would hunt better, and form deeper relationships. And individuals with exceptionally good communication would rise as leaders and coordinators.
This might be why we do not see many problems with speech (in comparison to its complexity). Evolution thinks this one ability is extremely important for passing on genes.
I've heard it suggested that language made the big difference. We bummed around for 998 million years, not able to improve our lot much - but somehow, 2 million years ago we developed language, and after that we were able to rapidly improve (and even co-evolve with our improvements - I've heard that the invention of the baby sling allowed our brains to grow larger than without it).
it actually seems implausible that a genetic mutation would produce a language "organ" as it would confer no advantage to an individual in a society where your peers had no language skills.
This is a non-sequitur because you're implying that such a mutation would be binary: either a creature has it and can communicate with creatures that have the same, or it hasn't and communication is impossible. That's not how evolution works, specialization of organs can happen over thousands of generations. If a specific mutation is beneficial, it spreads through the population over time, and additional mutations in that area can further develop the organ.
Second, our speech apparatus isn't one "organ" in the narrow sense: our lungs/vocal chords/tongue/lips/cheeks/jaw all contribute to the richness of our speech. The breadth of our speaking ability is a specialization of fine muscle control in all those areas, coupled with a finely-tuned hearing apparatus to analyze and understand those sounds.
It doesn't seem like an extraordinary claim to me that our evolutionary path has enhanced our communication ability far beyond our peer species -- because it's clear to see how a rich vocubulary can aid a species' survival over time. I have no knowledge of Chomsky's specific claims, but I don't think you are representing his theory accurately.
as a layperson, i have a hunch that language first developed as a defense mechanism against predators, and continued (perhaps more rapidly) with the proliferation of hunting weapons and methods.
an article/thesis from last year claims to have decoded gibbon vocalizations for distinct predators, as well as what the predators were doing [1].
and a while back i remember reading a theory that consumption of animal-based protein increased the brain size of early humans.
barring a monolith [2] my guess is that crude hunting tools provided more brain food for less work which, in turn, led to the development of more sophisticated tools and hunting methods.
so if the presence of predators caused early humans to develop simple words and grammar, perhaps a better-fueled brain, as well as the desire to teach and learn better tool development/use and hunting methods, expanded and improved this early grammar into something that could be used to communicate (e.g.) abstractions.
as a layperson, this process would seem to involve more than the mutation of one gene (e.g. FOXP_{2}), it would seem to involve lots of stuff: chemicals related to fear, stress, changes in diet, group dynamics, and so forth.
Some researchers believe articulated language arose after the last out-of-Africa event. If that's the case, it's possible the gene(s) arose outside of Africa and migrated back into Africa from, e.g., Asia. And that primitive articulated language with grammar, etc, as we understand it arose multiple times independently.
Most researchers believe the cognitive prerequisites for articulated speech came before and drove the emergence of the physical ability for articulated speech. But Joseph Jordania, for example, argues that speech evolved from choral singing, which arose as a defense mechanism on the savannah where groups of human ancestors would vocalize and gyrate in unison to intimidate predators. The emergence of this particular strategy explains, he argues, why our ancestors, after descending from the trees, didn't evolve more typical defense mechanisms like becoming bigger, growing thicker hides, being able to run faster, etc.
The group intimidation display selected for many things, including the ability to dance and sing in a group, because if you weren't in unison with the group, or if you tried to run away, you'd be the first to be eaten. This also explains, he argues, why people can become entranced while dancing in a group. It also, FWIW, neatly skirts the dilemma of so-called group genetic selection--the free-rider problem is taken care of by the hungry lion, and we don't require a complex, unproven fitness model for how cheating was suppressed; classic genetic models would explain how such extremely cooperative behavior could arise and persist among members not immediately related genetically (i.e. not extended family).
In that scenario the physical aspects of articulated speech could arise first, and the last piece of the cognitive puzzle could have come last, possibly long after out-of-Africa. But that last piece might have been so advantageous that it could have quickly migrated everywhere, including back into Africa.
In Jordania's model African and European populations were the last to receive articulated speech. He predicts, among other things, that polyphonic (i.e. choral, aka group) singing would be more common in European and African societies. And that articulated speech glitches, like stuttering, would be more common in Europe and Africa than in Asia, as Asian populations would have had more time to see these things suppressed in their populations.
In a similar vein, if (just throwing this out there off the top of my head) the last common ancestor of apes and humans was 4 million years ago, why haven't apes evolved speech and tool making in those 4 million years?
Joseph Jordania theorizes that human intelligence preceded articulated speech, which he suggests may have arisen as a simple neurological mutation in East Asia about 40k years ago and quickly migrated back toward Europe and Africa.
Jordania is an ethnomusicologist and believes that human vocal chords evolved for polyphonic singing, part of an adaptation (along with dance) permitting humans to act in tight orchestration for, e.g., defense and intimidation. This social mimicry permitted them to create an ecological niche into which both intelligence and altruism could grow, with articulated speech (i.e. language as we know it today) being the very last and quite recent step, and perhaps the most important distinguishing characteristic--IOW, presumably closely related hominids were nearly as or similarly intelligent, just lacking the ability for complex, individual speech with its concomitant benefits (greater specialization and more sophisticated culture?).
AFAIU, this is in stark contrast to most anthropologists, who generally believe things happened in the reverse order, with simple language (e.g. sign language) providing the impetus for vocal chord development, which in turn laid the foundation for rapid coevolution of greater intelligence.
A few hundred years wouldn't evolve a species out of the ability to use language. Language isn't cultural. If you take a dozen babies from different cultures/language communities, and cut off their tongues, and if their caregivers never speak to them, they will still find a way to use a pidgin language among themselves, because human language is innate.
If that was true, then why did humans evolve to speak at all? Why, if speech is simply a reaction to statistics we are tracking and behaviours that have been rewarded, would the first utterances have been made? And how do we make completely novel utterances that attempt to express our otherwise abstract thoughts?
I believe the prevailing hypothesis is that there was a tiny mutation in a human brain ~50,000 years ago that causes spoken language to be possible, but there are other ideas. It's a fascinating area of research:
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