Right...
I can think of a few things.

1) "Shared Genetic Ancestor"
This is true, humans and monkeys have a common ancestor. Go back a bit further (a bit being millions of years) and there'll be a common ancestor to apes and rodents.
If I remember correctly, there's evidence linking humans all the way back to tree shrews.

2) "It's all down to bone structure"
In biology, there's a term that gets used in situations like this. That term is "analogous structures".
Best example of this is bird and bat wings. Both do the same job, but achieve it in different ways (feathers, bones, skin).
The arguement is that as long as there's a pressure*, a way of coping will emerge, over time, by various means.
You can cut a rope with a knife or with a flame. Different ways of doing the same job.

My point is that rodent and ape "hands" might just be performing a similar function, not being identical.


I could go on, but it's late, and I have to be up in three and a half hours.


*Selection pressure - a "need" to be able to do something.
( Cawl, Mon 4 Aug 2008, 1:02, Reply)