[In Depth] A new evolutionary classic
An army ant colony does not welcome outsiders. Yet within the nests of most species of army ants, quietly stealing nourishment from their unwitting hosts, live tiny beetles that have evolved to look, smell, and behave just like their hosts. They have managed this evolutionary feat not just once, but at least a dozen times, new research shows. There are other classic examples of parallel evolution, but those species had a recent common ancestor, whereas the rove beetles have been diverging for more than a hundred million years. And just as ant colonies are jackpots for ant look-alike rove beetles, so, too, are termite nests. Based on a morphologically based family tree, other researchers propose that an adaptation of some beetles for living and hunting in sand helped protect the first beetle parasites from the termite attack. Now, some of these rove beetles have come to look and act just like...