Hi Xander.
Lets look at a few points.
"Also if speech did develope so slowly why is it so wide spread?Wouldn't different groups of humans through out the world have different speaking capabillities?
Do you realize how silly this sound? Imagine, say, a world were people in North America mostly speak English. But, then, there is another continent - let's call it Africa - were people DON'T speak English, but a number of tribal dialects.
Are entire words and concepts missing from their language? YES! Is it obvious their language 'evolved' along different lines than the Romantic languages. Well, yeah."
I think here we are confusing language and speech.
As far as I know you can take a human baby born to any race around the world and they will learn the language of their country.
Doesn't matter if its english french or Boga woga.
We all have the same structures in or brain to understand language.
To interperate gramma and sounds.
All humans have this same ability.
So language ability as we know had to be in place within human before they spread around the globe.
"I]Take Autisum. Although people do have it to different degrees it is quite a major difference.[/I]
Don't know why you keep bringing this up. Autism is a mental defect. Speech isn't - many (?most?) animals can do it. It is just the degree of information that can be communicated that changes."
What we call defects are what other call genetic change.
It is only a defect when it is of no use , if the defect is useful and can be passed on it is now an hereditary advantage.
The point is top show that these changes that can occour in the human brain are often large and have other side effects.
Although there are smaller differences that can occour we musn't ignore the fact that often small changes in brain stucture can have larger effects and also effect seamingly unrelated parts of the brain.
Can we really asume that laguage and other abilities has developed only slowly through time around the world when even today people are born with major defects or differences to their brain stucture?