On 19-7-2009 19:34, Darren New wrote:
> clipka wrote:

>> So intially the 47-chromosome population must have been comparatively
>> successful.
> 
> Or it's less hard to combine 48 with 46 than you might think. All the 
> data is there, including the tollermerines (or however you spell it) in 
> the middle.
centromere?
I don't think everything is preserved, there may be a small part 
missing, I assume that is more than just the telomeres (if that is the 
other word you were looking for ;) ):
http://www.don-lindsay-archive.org/creation/translocation.html
apparently that was not crucial.
One reason to bring this point up is that the difference in chromosome 
number is mentioned as one of the reasons why we can not interbreed with 
chimps. If that is the case than you can not have different numbers of 
chromosomes in various species. But you do, hence it must be more subtle 
than that. When it first happens crossover during meiosis may be 
impaired in the 47 chromosome individuals, but as long as the rest 
matches, we can apparently get away with it.

Some random thoughs (that I am not sure if I tried those out here before)
The individual in which this translocation happened is undoubtedly one 
of the ancestors of all men (as are the individuals in which the 
inversions first appeared).* Slightly more speculative is my guess that 
this or one of the inversions was the mutation that caused a form of 
neotony in that ancestor. That would have resulted in a less strong but 
more 'intelligent' individual. Which would have been a handicap in the 
chimp and to a lesser extend the bonobo type of society for a male but a 
huge advantage for a female. Hence: I think that particular ancestor was 
a female (one of our Eves). It would be interesting to try to date those 
mutations.

* if we have 30000 genes and we have 98% of our genes in common with the 
two species of chimp than there are at least 300 ancestors common to all 
humans since our split of the chimp line, and probably much more.

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