[extropy-chat] Hybrids

[David Lubkin]

No one responded to the question I posed a couple weeks ago, so I'll ask 
again. It was asked in a reply to a religious thread, so many people may 
have missed it.

>How is it that a horse and a donkey -- different species, with different 
>numbers of chromosomes -- can produce offspring?  What are the limits of 
>cross-species mating, besides incompatible hardware, e.g., horse and 
>gerbil?  Given species x, y and gestational periods g(x) and g(y), 
>respectively, what will the gestational period of an x carrying an x/y 
>hybrid be?

Beyond being interesting in their own rights, the limits of genetic 
differences that will produce fertile offspring without technological 
assistance are an important consideration in forthcoming human genemods.

Just as I want some people living off-Earth in an environment that can be 
viably self-sufficient with primitive technology, I would prefer that 
humans not fracture into reproductively incompatible successor species.


-- David Lubkin.