Son of Leeds wrote:Forgive me for bringing down to baby level - I'm Eg. Lit. - but does this mean they've found a language gene to support Noam's theory of a mutation?
Long post incoming!
Disclaimer: You'll soon notice that this post is hedged around with modal verbs and adverbs. That's because most of this is still ongoing investigation, little is proven 100% still.
Chomsky's assertion that Language is the result of a genetic mutation unique to humans was a bit like Darwin's theory of Evolution. It seems blindingly obvious but how come nobody thought of it before?
Like evolution, later research provided empirical proof he was right. Unlike evolutionary theory we haven't had very long at it. Chomsky's groundbreaking work was published in 1956 and the double helix had only just been discovered.
There's no single gene responsible for Language.
There, I've said it.
However, it seems likely that FOXP2 on chromosome 7 has a mutation in humans that has a decisive role to play.
It seems likely that the FOXP2 mutation makes it possible for two types of memory to work together. Humans can use declarative memory (knowing what) and procedural memory (knowing how) at the same time. No other animal can do that, and it's necessary for Language.
So we might say that FOXP2 in its human expression may serve as a kind of connector that allows different types of cognitive function to access each other.
And that makes Language possible.
There's two main reasons for thinking that FOXP2 is a major player in Language acquisition.
1. People who have damage to the FOXP2 gene have very serious problems in processing language, but seem to have no other noticeable cognitive impairment that can't be attributed back to the paucity of their language. They have no spatial awareness impairment for example.
This backs up Chomsky's theory that the language faculty is a stand-alone system. All the evidence points to this being the case. Not only the FOXP2 impairment.
The opposite is also true. People who have severe cognitive in other areas speak perfectly well.
At the current state of knowledge it's hard to argue against him. Some do, of course, but it's mostly hand waving and LOOK AT ME!
2. Through mitochondrial DNA it's possible to date when a genetic mutation probably happened.
The FOXP2 mutation probably happened around the time that Language emerged. This could be coincidence and we don't know exactly when Language emerged because spoken language leaves no fossils. But human behaviour does, and around 100-200kya humans suddenly begin to be symbolic creatures, and everything flows from that.
This all leads Chomsky and most others to think that Language didn't slowly develop over a very long time, but happened very quickly as the FOXP2 mutation spread throughout the species.
You have to remember that the earliest humans were a very small tribe, possibly a collection of tribes, but the numbers were tiny. A genetic mutation that gave an evolutionary advantage ( and Language is a massive evolutionary advantage) would spread through the population in a few generations.
So, nobody knows exactly what the FOXP2 mutation does yet, but it seems to be fundamental.
There have been experiments with mice given the human expression of FOXP2 and whilst obviously they didn't start speaking, they did show advanced cognitive skills.
Absolutely enthralling area of study advancing at a terrifying rate. Very very hard to keep up if you're not in the game at a high level, but it's fun trying.
Mirrors and copulation are abominable, since they both multiply the numbers of men.