Re: Species [arbitrary to a degree]

[NJPharris@aol.com]

In a message dated 10/19/01 5:44:35 PM Eastern Daylight Time, ELurio@aol.com 
writes:

> The difinition of a species has always been any group of organisms who can 
>  produce fertile decendants.

Well, that hasn't been true for a while.  And it's not that simple.  For 
instance, if you cross an Asiatic Leopard Cat with a house cat, you will get 
(mostly) fertile female offspring and sterile male offspring.  Yet the two 
species are different enough that almost any systematist would be loath to 
call them the same species, and, indeed, genetic studies indicate that 
Leopard Cats are at least as closely related to lions as to house cats.

Interfertility is a very tricky business.  Individuals from relatively 
genetically distant species may be able to produce fertile offspring, while 
more closely related species may not be able to produce viable offspring at 
all (e.g. chimps and humans).

--Nick P.