Wed, 05 Nov 1997 22:03:58 -0600 you wrote,
>At 01:12 PM 11/5/97 -0600, Karen G. Jensen wrote:
>>Of course there is adaptation within each kind, so the raven and the crow
>>and other corvids have differentiated from the original. But there are
>>limits to such change.
>I haven't seen a limit to change. Look at what the wolf has been turned
>into. St. Bernards, chihuahuas, dachsunds etc. This change has occurred
>over a period of only 10,000 years. The usual retort is that they are still
>dogs. But if you killed off every dog in between the St. Bernard and the
>chihuahua, you would have classified them as different species, because they
>wouldn't breed.
And just think what paleontologists looking at St. Bernard bones and
Chihuahua bones would do if they didn't know about everything in between --
they might call them different genera, when they are really one species,
albeit more of a rasen-kreise (or however you spell it -- a gradation, the
opposite ends of which probably couldn't directly interbreed).
There has been a lot of speciation, I believe to the family level in many
plant kinds, and some animals. Things have had to adapt a lot as the
environments have changed. This doesn't negate the concept of kinds. It
shows how much versitility has been given to living organisms. But there
are genetic limits, as plant and animal breeders well know.
Karen