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From: wrp@biochsn.acc.Virginia.EDU (William R. Pearson)
Newsgroups: sci.bio
Subject: Re: Coelocanth and evolution:x
Message-ID: <1991Jun4.124541.25552@murdoch.acc.Virginia.EDU>
Date: 4 Jun 91 12:45:41 GMT
References: <17580003@hpfcdj.HP.COM>
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In article <17580003@hpfcdj.HP.COM> sharp@hpfcdj.HP.COM (Darrin Sharp) writes:
]
]	Last night, on the "National Geographic Explorer",
]	there was a segment on the coelocanth (sp?). This
]	is a fish that was thought to be extinct, but live
]	specimens were rediscovered in the 1930's off the
]	S.E. coast of Africa. Since then, several are
]	caught each year.
]
]	The show made mention of the fact that these fish
]	were unchanged for the last 400 million years.
]
]	I know that outwardly, the live specimens very closely
]	resemble the 400 million year old fossils. But how
]	can this be? Is it common for organisms to not evolve
]	for 400 million years? How long has it been since sharks
]	and alligators/turtles/crocodiles evolved? Any other
]	species that haven't changed in this long? 
]
]	Darrin Sharp (sharp@hpfcla.fc.hp.com)

	This claim is frequently made about animals that physically
resemble ancient ancestors.  It is, of course, false.  There are many
examples of "primitive" organisms that exist in an "unchanged" state.
At the molecular level, their enzymes and DNA have diverged at the same
rate as "modern" animals.  If an organism is living today, it is "modern,"
regardless of how it looks.

Bill Pearson