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Old 09-04-2003, 09:08 PM
Rich Conley
 
Posts: n/a
Default [IBC] evil squirrels!

yes, but it is now defined as reproductive isolation in an equal competition
setting. IE given normal numbers of females of each group, and one male, if he will
only breed with the same color form, they are considered seperate species as they
are different genetic groups. As time goes, they get further and further genetically
from each other....

The rules of speciation have changed drastically in the last 10 years, mostly to
deal with the African Cichlid Fishes in the rift lake regions. (active speciation is
happening in these lakes, as they are relatively new bodies of water ~5000 years).
What has been decided is that the fact that a species CAN NOT breed with another
bears no relevance...it is whether this breeding happens naturally in the wild.

For example, many species of bird are cpaable of breeding with birds in different
GENUS. It just does not happen, so they are considered different species...

Most Canines can cross breed (wolves, dogs, coyotes, etc.) yet they are considered
different species because they dont. My point is, reproductive isolation can be
voluntary, not just a lack of the mechanisms to breed.

"David J. Bockman" wrote:

I'm pretty certain the unequivocal definition of a species is 'reproductive
isolation'.

David J. Bockman, Fairfax, VA (USDA Hardiness Zone 7)
Bunabayashi Bonsai On The World Wide Web: http://www.bunabayashi.com
email:

-----Original Message-----
From: Internet Bonsai Club ]On Behalf
Of Rich Conley
Sent: Tuesday, April 08, 2003 4:24 PM
To:

Subject: [IBC] evil squirrels!


If they will not breed with the grey squirrels, they are a
seperate species. For
speciation to occur, it does not have to be that they can not
mate, the fact that
they will not breed is just as valid.

Geographic isolation is as much an accepted qualification for
speciation as genetic
differences. They are isolated, so the population is drifting
away from what it
originally came from.


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