Richard Black, science writer for the BBC, pointed it out in an article he wrote recently. He observed that the whale shark has gotten smaller over the past decade from an average of 22 feet to an average of 15 feet. He opines, "The most likely explanation is that fishermen are pulling the biggest whale sharks they can find out of the ocean, either because they're the easiest to spot or because they're the most lucrative catches." So, the "bigness" trait is less likely to be passed on, the smaller fishes surviving -- or whatever.
The volcano keyhole limpet is getting smaller, too. So, what's the explanation there? Pollution? Warming waters? Sometimes, Nature is not so obvious.
Posted by Bill at January 15, 2009 08:14 AM