Two new Homo fossils are described in this week’s Nature, and here they are.
Pharyngula
Evolution, development, and random biological ejaculations from a godless liberal
Two new Homo fossils are described in this week’s Nature, and here they are.
Since I was asked what a cnidarian “head” is in reference to this work on multi-headed cnidarians, I’ll answer. In short, they don’t have one.
People are always arguing about whether primitive apes could have evolved into men, but that one seems obvious to me: of course they did! The resemblances are simply too close, so that questioning it always seems silly. One interesting and more difficult question is how oysters could be related to squid; one’s a flat, sessile blob with a hard shell, and the other is a jet-propelled active predator with eyes and tentacles. Any family resemblance is almost completely lost in their long and divergent evolutionary history (although I do notice some unity of flavor among the various molluscs, which makes me wonder if gustatory sampling hasn’t received its proper due as a biochemical assay in evaluating phylogeny.)
One way to puzzle out anatomical relationships and make phylogenetic inferences is to study the embryology of the animals. Early development is often fairly well conserved, and the various parts and organization are simpler; I would argue that what’s important in the evolution of complex organisms anyway is the process of multicellular assembly, and it’s the rules of construction that we have to determine to identify pathways of change. Now a recent paper by Shigeno et al. traces the development of Nautilus and works out how the body plan is established, and the evolutionary pattern becomes apparent.
A few years ago, everyone was in a tizzy over the discovery of Flores Man, curious hominin remains found on an Indonesian island that had a number of astonishing features: they were relatively recent, less than 20,000 years old; they were not modern humans, but of unsettled affinity, with some even arguing that they were like australopithecines; and just as weird, they were tiny, a people only about 3 feet tall with a cranial capacity comparable to a chimpanzee’s. This was sensational. Then on top of that, add more controversy with some people claiming that the investigators had it all wrong, and they were looking at pathological microcephalics from an isolated, inbred population, and then there were all kinds of territorial disputes and political showboating going on, with the specimens taken out of the hands of the discoverers, passed off to a distinguished elderly scientist whose lab damaged them, etc., etc., etc. It was a mess of a story, and the basic scientific issues are still unsettled.
Now the leader of the investigators who found the specimens has written a book, A New Human: The Startling Discovery and Strange Story of the “Hobbits” of Flores, Indonesia(amzn/b&n/abe/pwll), by Mike Morwood and Penny Van Oosterzee. I’m coming to this a bit late — Afarensis reviewed it already this spring — but finally got far enough down in my pile of books to encounter it.
Feeling pragmatic? Is your focus entirely practical, on what works and what will get the job done? Are you one of those fighters for evolutionary biology who waves away all the theory and the abstractions and the strange experimental manipulations, and thinks the best argument for evolution is the fact that it works and is important? This book, The Evolving World: Evolution in Everyday Life(amzn/b&n/abe/pwll) by David Mindell, does make you sit down and learn a little history and philosophy to start off, but the focus throughout is on the application of evolution to the real world. It does a fine job of it, too.
A correspondent just reminded me of this classic paper from the literature—it’s the only contemporary scientific work I know of that managed to combine a discussion of the induction of a tissue by TGF-β and BMP proteins with a discussion of the Hebrew noun tzela to suggest that the book of Genesis wasn’t talking about thoracic ribs at all. All us sneering atheist professors who’ve had to exhibit human skeletons to show the creationists in our classrooms that men are not missing a rib apparently should have been pointing a little lower — where humans are missing a bone.
This comment on the Panda’s Thumb leads to a very interesting entry on OMIM, the database of human genetic characters. We’re missing something.
OS PENIS, CONGENITAL ABSENCE OF
Deletion of the gulonolactone oxidase gene on 8p21 is a genetic disease that affects 100% of humans. Lack of the enzyme causes severe connective tissue disease and makes humans dependent upon dietary supplements of ascorbic acid; see 240400. Gilbert and Zevit (2001) pointed out that another genetic condition, affecting 100% of human males, is congenital lack of a baculum (os priapi; os penis). Whereas most mammals (including common species such as dogs and mice) and most other primates (except spider monkeys) have a penile bone, human males lack this bone and must rely on fluid hydraulics to maintain erections. The size of the rodent baculum is regulated by the posterior members of the HOXD (142987) set of transcription factors. Gilbert and Zevit (2001) suggested that it was not a costal rib but rather the penile ‘rib’ or baculum that God removed from Adam to create Eve (Genesis 2:21-23). Genesis also states that ‘the Lord God closed up the flesh.’ Gilbert and Zevit (2001) suggested that the raphe on the penis and scrotum was thought to be the surgical scar.
I’m a deformed mutant, a pathetic shadow of my bold, upright ancestors. My only consolation is that all you other guys are, too.
The first review of my talk yesterday is in! Too bad it is from somebody who wasn’t there and who is a world-class fool. Yes, it’s Michael Egnor again, and he’s got a lengthy post up with the pretext of giving me advice on future talks, but is really an attempt to preempt my arguments and chide me for my crazy materialist position. He doesn’t even come close to any of my arguments, and he makes false assumptions all over the place about what I and the audience think. I’m used to straw men from creationists, but this is ridiculous.
Here’s what I actually said at the talk.
Why me, O Lord, why me?
One of the more recent books sent to me is Thank God for Evolution!: How the Marriage of Science and Religion Will Transform Your Life and Our World(amzn/b&n/abe/pwll) by Michael Dowd. I have read it, and I’m feeling biblical.
My God, my God, why hast thou forsaken me? why art thou so far from helping me, and from the words of my roaring?
Psalm 22:1
If you’ve been reading that fascinating graphic novel, Y: The Last Man(amzn/b&n/abe/pwll), you know the premise: a mysterious disease has swept over the planet and bloodily killed every male mammal except two, a human named Yorick and a monkey named Ampersand. Substantial parts of it are biologically nearly impossible: the wide cross-species susceptibility, the near instantaneous lethality, and the simultaneity of its effect everywhere (there are also all kinds of weird correlations with other sort of magical putative causes, which may be red herrings). On the other hand, the sociological part of the story seems very plausible. There is no feminist utopia, the world goes on in a traumatized and rather complicated way, and the reactions everywhere vary from crazed euphoria to a more common despair. One thing that isn’t at all implausible, and actually has been observed, is a plague that selectively exterminates males.
(hat tip to Branch of the NCSE)
