The chambered nautilus is on the decline, after 500 million years of survival from the world’s greatest extinction events. Guess who’s to blame.
At the Philadelphia Inquirer, Faye Flam wrote about the nautilus, a “living fossil” that has survived all that planet Earth could throw at it for 500 million years. It survived the Permian Extinction that wiped out 90% of species on Earth, and the fabled K-T extinction event that wiped out the dinosaurs. But now, its days are numbered, and humans are to blame. Presumably, it’s because hunting of the prized shells caught them by surprise:
So as hardy as these creatures have proven over hundreds of millions of years, a new fitness factor is becoming increasingly important — the ability to coexist with 7 billion human beings. There’s nothing the nautilus can do to adapt to the threat from humans — it came on too suddenly. The future of these animals depends not on what they do, but on what we do.
This is Flam’s latest entry under “Planet of the Apes,” a blog on evolution. Her post, echoed on PhysOrg, contained some implausible elements. For one, was human hunting of the nautilus any more sudden than an asteroid impact? Second, how many out of 7 billion human beings are nautilus fishermen? Third, how big is the nautilus habitat in the vast oceans of the world? Fourth, what does the nautilus have to do with evolution?
Ammonoids, of which the nautilus is a member, are complex animals that appeared in the Cambrian Explosion, “Darwin’s Dilemma” – the abrupt, non-evolutionary appearance of all the animal phyla in a geological eye-blink in evolutionary terms. “Nautiloid fossils have been dated as early as 500 million years ago — soon after animals started leaving fossils,” she wrote. And they are “living fossils,” basically unchanged in body plan for over 500 million years.
In addition, Flam reduced evolution from the realm of natural law to happenstance:
The story of the nautiloids helps illustrate the role of chance in evolution. Extinction doesn’t reflect some kind of flaw or weakness or inability to adapt. The term “fitness” as scientists use it depends on the environment — don’t think of workout-hardened athletes but of individuals that fit well into their surroundings. And on this planet, the surroundings are always subject to change….
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