Showing posts with label human evolution. Show all posts
Showing posts with label human evolution. Show all posts

Friday, May 22, 2009

Primate Fossil being pitched as the second coming of Christ, hurting the cause.



The fossil is admittedly really cool. It certainly is up there with some other impressive fossils and it could shed some light on primate ancestry but in many other ways it's not as cool as tiktaalik or archeopteryx. It really does look like a monkey. It might shed some light on primate evolution and thus our evolution but then so did Tiktaalik, and I wasn't joking in the title. It's actually being hyped as the second coming of Christ. One of the dates listed in the hyperbolic advertisement for the program was 0AD. Despite the fact that there was no 0AD, it's a pretty clear reference to Jesus and putting this up there with the importance of the supposed date of the birth of a mythological character during the time when both the Gospel of Luke and the Gospel of Matthew rule out as a supportable birth year (after 4CE Herod the great isn't alive to murder the children, before 7AD there's no supposed Roman governor to order a census).

So when creationists chime back in and point out that it's one fossil that looked like a monkey and that's where all the damned evolutionists put their marbles in one last grasp to try and justify their "made from nothing" theory... they will be partially right. The hype is massively overblown.

Sunday, August 10, 2008

I'm not convinced: Neandertals still might have interbred

The nail in the coffin of theory that Neandertals interbred with modern humans is typically the mitochondrial DNA which typically shows that Neandertals broke off of the human family tree prior to modern humans. We typically use 100,000 years as a demarcation for human, although in reality our ancestors have always been the same species as far as you go back even if that species is a type of fish or worm. Deciding when during an evolution to say this is a new species is an arbitrary point. Anyhow it seems on pretty good authority that Neandertals last shared a common ancestor with humans 660,000 years ago, so they certainly aren't an ancestor but a near cousin (in the same sense that the tree out my window is a distant cousin). Mitochondrial DNA (as you well know because you're smart (if not you will be)) is passed from mother to child along a material line all the way back to the mitochondrial eve (scientists need to stop calling shit Adam or Eve they make for really bad names).

Now this seems pretty clear that no genetic material was passed around between the neandertal population and the human population when the human population left Africa for Europe, right? Well, I'm not convinced. Neandertals were strong, really strong, Arnold Schwarzenegger Mr. Universe strong and this holds true for the women as well. In order to get our mitochondrial DNA to show signs of Neandertal interbreeding we need to posit that a man had sex with a fairly ugly brow face woman capable of breaking him in half and that from that union somehow the kid got taken care of from the human side (even though mommy would raise him) and that from that there is a *direct* maternal line going back at least 15,000 years and these one of these individuals wasn't picked up by a small sampling of the human population.

1) Neandertal men + human women = much more likely.
2) Sample size might be too small to find mRNA traces within human population.
3) The traces might have just been lost.

I don't mean this to sound like special pleading by any extent, rather I just don't find mitochondrial DNA to be a nail in the coffin. We really might have had plenty of interbreding with the local population and bear no signs within our mitochondrial DNA.