evolution
razib | September 17, 2009Tyrannosaurid Skeletal Design First Evolved at Small Body Size:
Tyrannosaurid dinosaurs comprised nearly all large-bodied predators (>2.5 tons) on northern continents during the Late Cretaceous. We show that their most conspicuous functional specializations--a proportionately large skull, incisiform premaxillary teeth, expanded jaw-closing musculature, diminutive forelimb, and a hindlimb with cursorial proportions--were present in a new small-bodied, basal tyrannosauroid from Lower Cretaceous rocks in northeastern China. These specializations, scaled up in Late Cretaceous tyrannosaurids…
edyong | September 17, 2009
Meet Raptorex, the "king of thieves". It's a new species of dinosaur that looks, for all intents and purposes¸ like the mighty Tyrannosaurus rex, complete with large, powerful skull and tiny, comical forearms. But there's one very important difference - it's 100 times smaller. Unlike the ever-shrinking world of music players and phones, it seems that evolution crafted tyrannosaur technology with much smaller specifications before enlarging the design into the giant predators of the late Cretaceous.
Raptorex is a new species of meat-eating dinosaur, discovered in northwest China by Paul…
ejohnson | September 17, 2009
Most Americans are familiar with Darwin's theory of evolution by natural selection, but less well known is his personal struggle with the conflicting ideologies of science and religion. A new film from producer Jeremy Thomas, Creation, aims to tell the story of Darwin's life through the cinematic lens—but Americans who would pay the box office price to watch it unfold won't be able to. US distributors have opted not to pick up the film, which the Telegraph reports has gotten outstanding early reviews, due to concerns that its message won't sit well with religious groups. Ethan Siegel of…
emjohnson | September 17, 2009
Darwin evicts a Social Darwinist and Eugenicist from his house / Northwestern Univ.
Primatologist Frans de Waal, author of such classic works as Chimpanzee Politics, Peacemaking Among Primates, Good Natured: The Origin of Right and Wrong in Humans and Other Animals, and Bonobo: The Forgotten Ape is now coming out with his new book The Age of Empathy: Nature's Lessons for a Kinder Society. My review of this work will be out early next week to mark the book's national release on September 22. Today and in the next few days I will be reposting pieces I've written over the years on the…
edyong | September 16, 2009People with red-green colour blindness find it difficult to tell red hues from green ones because of a fault in a single gene. Their inheritance robs them of one of the three types of colour-sensitive cone cells that give us colour vision. With modern technology, scientists might be able to insert a working copy of the gene into the eye of a colour-blind person, restoring full colour vision.
You might think that the brain and eye would need substantial rewiring to make use of the new hardware, but Katherine Mancuso from the University of Washington thinks otherwise. She has used gene…
pharyngula | September 16, 2009There are no more excuses. None.
The defining characteristic of all arguments with creationists is how damned ignorant they are. I'm sure many scientists have been stupefied into stunned silence when they first encounter these people; these advocated of creationism are typically loud and certain and have invested much time and effort into apologetics, but when you sit down and try to have a serious discussion with them, you quickly discover that their knowledge of basic biology is nonexistent. It's worse than that. We're used to freshmen entering our classes who don't know much about the…
laelaps | September 16, 2009Considering the fossils of the Cambrian, the oldest fossil-bearing rocks known during his time, Charles Darwin wrote the following in the 6th edition of On the Origin of Species;
... it cannot be doubted that all the Cambrian and Silurian trilobites are descended from some on crustacean, which must have lived long before the Cambrian age, and which probably differed greatly from any known animal. ...
... if the theory be true, it is indisputable that before the lowest Cambrian stratum was deposited long periods elapsed, as long as, or probably far longer than, the whole interval from the…
razib | September 15, 2009The origin of Neandertals:
Western Eurasia yielded a rich Middle (MP) and Late Pleistocene (LP) fossil record documenting the evolution of the Neandertals that can be analyzed in light of recently acquired paleogenetical data, an abundance of archeological evidence, and a well-known environmental context. Their origin likely relates to an episode of recolonization of Western Eurasia by hominins of African origin carrying the Acheulean technology into Europe around 600 ka. An enhancement of both glacial and interglacial phases may have played a crucial role in this event, as well as in the…
laelaps | September 15, 2009
In 1916 the paleontologist H.F. Osborn published one of the strangest books on evolution I have ever read. Titled The Origin and Evolution of Life: On the theory of action, reaction and interaction of energy, the volume was an attempt to "take some of the initial steps toward an energy conception of Evolution and an energy conception of Heredity and away from the matter and form conceptions which have prevailed for over a century." Osborn hoped that by distilling the study of life to exchanges of energy the why of evolution would finally become apparent. (As I have mentioned before, Osborn…
emjohnson | September 14, 2009My previous post on a potential problem for the selfish gene theory in explaining cooperative behavior resulted in a fair amount of heated discussion. However, there are quite a few misconceptions regarding the controversy surrounding the selfish gene, group selection, multilevel selection, generalized reciprocity, etc. that need to be clarified. When Richard Dawkins published The Selfish Gene in 1976 it was an instant classic and has been championed for the past three decades as the final answer on how natural selection operates. What has been tremendously useful about the theory, as in…
jrosenhouse | September 13, 2009The Wall Street Journal recently hosted an exchange of essays on the subject of evolution and God. The participants: Richard Dawkins and Karen Armstrong. Here's your first question: Which of them wrote this:
Evolution has indeed dealt a blow to the idea of a benign creator, literally conceived. It tells us that there is no Intelligence controlling the cosmos, and that life itself is the result of a blind process of natural selection, in which innumerable species failed to survive. The fossil record reveals a natural history of pain, death and racial extinction, so if there was a divine…
razib | September 12, 2009The Evolutionary Origin of Man Can Be Traced in the Layers of Defunct Ancestral Alpha Satellites Flanking the Active Centromeres of Human Chromosomes. The authors are Russian, so I think the somewhat grand and archaic first portion of the title can be explained as a mater of translation. Here's the author summary:
The primate centromere evolves by amplification of alpha satellite sequences in its inner core, which expands and moves the peripheral sequences sideways, forming layers of different age in the "pericentromeric" area. The expanding centromere model poses two main questions: (1)…
edyong | September 12, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science.
In Jurassic Park, the role of Velociraptor was played by computer-generated reptilian actors, that bore little resemblance to the real deal. The actual dinosaur was smaller, slower and used its infamous claw to stab (or possibly climb) rather than disembowel. And in 2007, scientists found good evidence that it was covered in feathers.
Since Jurassic Park aired, dinosaurs like Velociraptor have received something of a makeover. It began in the late 1990s when Chinese palaeontologists found a…
laelaps | September 11, 2009
Carl Buell's restoration of Aetiocetus weltoni. From Demere et al., 2008.
By now many of you have no doubt seen the abysmally bad story on evolution and creationism in yesterday's Telegraph. After referring to the reactions of fundamentalist Christians to the forthcoming Charles Darwin biopic Creation (based upon the book Annie's Box), the anonymous author of the piece presents the "Top 5" arguments for both evolution and creationism. The choices were baffling; it appeared that rather than do any actual research the writer extracted the selections from a bodily orifice that I will refrain…
edyong | September 10, 2009The drawers of the world's museums are full of pinned, preserved and catalogued insects. These collections are more than just graveyards - they are a record of evolutionary battles waged between animals and their parasites. Today, these long-dead specimens act as "silent witnesses of evolutionary change", willing to tell their story to any biologist who knows the right question to ask.
This time round, the biologist was Emily Hornett, currently at UCL, and her question was "How have the ratios of male butterflies to female ones changed over time?" You would think that the sex ratios of…
grrlscientist | September 10, 2009tags: paleontology, fossils, dinosaurs, evolution, I am a Paleontologist, they might be giants, music video, streaming video
I have been remiss lately regarding music videos because I was in Finland for awhile, and then was otherwise preoccupied. But I just had to share this song with you; "I am a Paleontologist" is by the group, They Might be Giants and is one of many wonderful songs on their new album "Here Comes Science." If I was teaching biology or evolution this semester, I would use it in class.
You can order They Might be Giants' new album [CD/DVD], "Here Comes Science" from Amazon.
mikethemadbiologist | September 10, 2009A dissertation committee member who will remain nameless once told me, "Mike, in the end, it all comes down to those stupid fucking natural history facts." This might have been the only worthwhile thing said committee member ever told me. More about this in a bit.
Anyway, I bring this up because I think much of the commentary on Paul Krugman's recent NY Times piece about the problems with the current state of macroeconomics is missing the real problem. The problem wasn't with the theory.
Well, alright, the theory was bad. But the real problem is that there was no de facto mechanism to…
razib | September 10, 2009She seems to have liked it, with caveats and reservations. It's a narrative film, not a scientific biography, so appropriate shifts in emphases are to be expected.
awild | September 9, 2009
Multiple foundress queens of Acromyrmex versicolor atop their shared fungus garden.
A striking result from recent studies on the co-evolution of leafcutter ants and their fungus is that the two lineages do not show a tight pattern of coevolution. That is, the evolutionary relationships among the fungal lines often deviate from the phylogenetic trees shown by the ants. When ant populations speciate, the fungus doesn't follow.
The lack of cospeciation was puzzling, as the ants and the fungus are intertwined a tight ecological relationship. Each requires the other to survive. The…
ejohnson | September 9, 2009Darwin's On the Origin of Species is the book that introduced the theory of evolution by natural selection and launched the field of evolutionary biology. But the text itself evolved, too, from the first edition published in 1859 to the sixth in 1872. Chapters were shortened and lengthened, words added and deleted—though, more were put in than taken out, as the final edition measures in at 40,000 words longer than the original.
Ben Fry, director of Seed Visualization and the Phyllotaxis design laboratory in Cambridge, Massachusetts, has tracked these changes and put it all together in a…