[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Species concepts & interfertility



In a message dated 95-12-19 14:04:14 EST, Thomas_R_HOLTZ@umail.umd.edu (th81)
writes:

>For another case, brown bears (Ursus arctos) and polar bears (Ursus
>maritimus) are capable of having offspring (some of which are even
>viable!!).  Although most mammalogists agree that these are separate
>species, they have not yet diverged enough to prohibit chromosomal
alignment.
>
>

Right. I was more interested in how long it would take for mutual infertility
to arise than in pointing out why it could not have happened
"instantaneously."