[CarolinaGuitarman]

Not only is the modern coelacanth not the same species as the ancient ones, it's a different genus entirely. It has changed; there just has been any great selective pressure to change drastically. Organisms like the coelacanth and the shark are exceptional anyway.

[Antoninus]

Not only is the modern coelacanth not the same species as the ancient ones, it's a different genus entirely. It has changed; there just has been any great selective pressure to change drastically. Organisms like the coelacanth and the shark are exceptional anyway.

Proof of that? Dropping fossilized ancient creatures in a particular taxonomic classification is a completely academic exercise. Of the articles I've read claiming that the modern coelacanth is different from ancient ones, none has posited such a great variance as you have offered. The more convincing ones suggested that the differences may be more subtle--like improvements in the immune system.

However, it should be pointed out that variances exist within human immune systems as well, which is why certain pathogens can decimate a population in one area of the world, and have no effect in another. No one would argue, however, that a European who gets sleeping sickness is not the same species as an African who doesn't. Alright, perhaps a late-19th century social-Darwinist might.