Saturday, November 13, 2010

End of the Attenboroughnian Era

I've just watched the second and final part of David Attenborough's final original series First Life. It's a shame the series was so short but I suppose that there's only so much enthusing a man can do over protozoans, bacteria and sponges. But two episodes are better than none so kudos to the great safari suit wearing national treasure. Those first dramatic several billion years in the history of life are so often sidelined by more charismatic mega-vertebrates like the dinosaurs.

I was especially delighted by episode two and the CGI reconstructions of the bizarre creatures of the Burgess Shale fossil bed (If you've never heard of them, have a quick squint at my previous blog post here). If you ever wanted a better example to support an argument against Intelligent Design (ID), the Burgess Shale is perfect. What we have here (and supported by similar fossils from other shale beds) is undeniable evidence recorded in solid rock of a vast, sudden evolutionary explosion. Why would an intelligent designer create so many different variations of body plan and form and then consign nearly all of them to the dustbin? Every vertebrate on this planet, every creature with a backbone - mammals, reptiles, birds, amphibians, fish, monotremes - are all descended from a flat, worm-like, ribbon of a creature called pikaea; the first chordate that we know of. But pikaea is just one of hundreds of species represented in the Burgess Shale; creatures like opabinia with its five eyes and grasping Hoover extension-like claw. Opabinia was an evolutionary dead end like 99% of the creatures represented in the Burgess Shale. The trilobites were, at one time, the most sucssful creatures on the planet; we know of over 17,000 species of them and yet the fossil record is probably just scratching the surface of the true number. And yet there isn't a single trilobite left alive today. In fact, they'd been extinct for 250 million years before we even evolved. Why would an intelligent designer waste so much time and energy? Or was it just that Noah couldn't fit them all on the Ark? (If you want to read my debunking of that whole story, see here.) Want some great trilobite websites? Then click here.

While we're talking about ID, I came across another particularly shiny nail in its coffin this week when proofreading a relative's dissertation for their degree course. She's a midwife and her essay was about the mostly preventable problem of thromboembolism during pregnancy and immediately after childbirth. I was fascinated to read that, 'Initially it is the production of progesterone which causes changes to the blood vessels and in later pregnancy, it is the gravid uterus that obstructs venous return, especially on the left side where the left iliac vein, the right iliac artery and ovarian artery cross over each other. This compression only happens on the left side, supporting the propensity for a deep vein thrombosis to occur in the left leg.' In case the jargon got in the way there, what she's saying is that an occupied womb can constrict certain blood vessels causing, in rare circumstances, a blood clot that can be fatal. Would an intelligent designer have made such a fundamental error? The fact is, we were shaped by evolution from creatures that used to run about on all fours with our organs suspended from our spines. With the move to upright posture, those same organs now hang in positions they weren't designed to and, regrettably, this sometimes results in medical problems.

David Attenborough may be retiring from our screens but he has done much to promote the public understanding of science. For that he should be applauded (Why isn't he a lord yet?). Meanwhile, it's left to us - those of us who have grown up watching his shows - to carry the message on into the future. Evidence not belief. Science not pseudo science and mumbo jumbo. Critical thinking and scepticism not blind, unquestioning indoctrination.

That's his legacy.

1 comment:

John S. said...

Have just, after many decades as a biologist, become interested in trilobites. Please can you give the ID of the specimens illustrating this blog? Thanks.

Keep up the good work. How anyone can seriously cling to intelligent design has always been a mystery to me.

John S.