No, no, not muscles – mussels – those little barnacle-like things that live in the water. For those that doubt that evolution is real (and I mean that evolution occurs at all, not whether or not humans evolved from apes), here is yet another fine example of documented evolution in response to a changing habitat.
Some 15 years ago, blue mussels knew their enemies and had a rather peaceful life in the New England waters. But when an invasive crab species turned up, the mussels moved quickly to defend themselves against this new predator by thickening their shells.
Such rapid evolutionary response is a “nanosecond” compared with the thousands of years that it normally takes for a species to respond to a predator.
“It’s the blending of ecological and evolutionary time,” said study co-author Aaren Freeman, a graduate student the University of New Hampshire. “It’s an important development in the arms race between these crabs and these mollusks.”
There you have it. Mussels evolve to protect themselves. Let me know if you’d like more examples of evolution. Oh, and if you can’t be arsed to read the article, the invasive crab species in question is Hemigrapsus sanguineus, but I’m sure you already knew that.
[tags]The evolution of mussels, Evolution in 15 years, Crabs like mussels[/tags]