Friday, June 22, 2007

River out of Eden

My son Dan designs and maintains websites for businesses. His company is called Platypus Multimedia. I'm not sure why Dan chose the platypus as his icon, but I suspect he was trying to suggest innovation and originality. He may have got it partly wrong.

In Richard Dawkins' The Ancestor's Tale: A Pilgrimage to the Dawn of Time, we meet the platypus in our backwards journey at 180 million years before the present. We are marching into the past in search of ancestors, and by the time we meet the platypus we have joined up with all of our other mammalian cousins, placentals and marsupials. We are deep into the Age of Reptiles, and what ancestors we meet are tiny shrewlike nocturnal creatures, doing their best to stay out of the mouths of dinosaurs. And now, along comes another almost solitary pilgrim from the present, the duckbill platypus, that most unlikely of animals -- like something God put together out of leftover parts on the eighth day of creation. A couple of echidnas are tagging along. This ragtag group are known as monotremes, which means "single hole" in Greek; like reptiles and birds -- but not other mammals -- their anus, urinary tract and reproductive tract share a single opening. Even more reptilian, the monotremes lay eggs.

The duckbill platypus would appear to be a not-so-missing link between the Age of Reptiles and the Age of Mammals. Of course, it will not be the duckbill itself we find slithering around 180 million years ago, but the duckbill's (and our) ancestor. Nevertheless, the platypus seems to have retained more ancestral characteristics than have other mammals. That is to say, in a fundamental way, the platypus may be the least innovative of our mammalian cousins.

But not to worry, Dan. The platypus has innovations of its own. That supersensitive bill, for one thing. It is one of the most magnificent sense organs in creaturedom, able to pick up subtle electrical emanations from prey. Then there's the stinging back feet; another innovation unique among animals. And let's face it; we also love the duckbill platypus for its sweetly goofy look and name.

While I've been writing this, I have been watching a crane fly at my window, another lovably goofy creature, with its improbably threadlike legs. Having joined up with the platypus, we have a long way to go on our pilgrimage before we meet our common ancestor with the crane fly -- at least another 400 million years.