Asshat Redux

barrington, you're quite right - Richard Dawkins is at his best when extolling science rather than bashing everything else. In fact my hair stood up a little at the introduction to Light Will Be Thrown:

The famous [quote from Origin of Species] "Light will be thrown on the origin of man and his history" is a calculated understatement matched, in the annals of science, only by Watson and Crick's "It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material."

Thanks to everyone who gave a definition of evolution! Even the smartypants amongst you. :-) From another Dawkins essay, here's something that approaches a definition: "cumulative evolution by nonrandom survival of random hereditary changes..." Most of the definitions offered covered those three bases - random mutation, nonrandom natural selection, cumulative change.

As I mentioned in a comment, John Safran did a terrific rant monologue about people who smugly mock Creationists, but themselves know little about the Big Bang or evolution. Oddly for someone with a degree in Biology (but less oddly when you remember my actual profession) I'd feel more confident right now explaining the Big Bang than I would explaining the evidence for evolution. I'm going to have a crack at the 29+ Evidences for Macroevolution document over at the talk.origins Archive - it looks dauntingly technical, but I'll try to summarise some of it in lay language here. Not so much to ensure you lot can explain anatomical parahomology at parties, but because trying to explain something to another person is the best way I know of learning it.

\O_o/ - Altered Snakes!

omg. According to Dawkins, it's possible to induce snakes to grow legs. That is, to switch on the leg genes lying dormant in their DNA.

That's one powerful piece of evidence that snakes descended from a ancestor which had legs - why would a designer, creating the snake as is, include leg genes? (A 95 million year old fossil legged snake has recently turned up.*)

It's also incredibly cool. *goes about making snakes grow legs*


* I don't mean it walked.

I once read a great sentence in National Geographic: "Seeking to learn more about feathered dinosaurs, I flew to China."

(no subject)

There's a pichur of the fossil legged snake here, and also a super gross image of a blindsnake, which looks like someone's innards. Plus an explanation of the genes involved.

(The link to Nature is to a paper about making pythons grow complete legs - they have vestigial leg buds - using the gene with the best ever name, sonic hedgehog.)

ETA: I got so excited about the blindsnake that I didn't realise the pichur was of a different, unleggled fossil snake. I found a picture of the real fossil, showing the fully developed hind legs right down to the toes!