evolution
grrlscientist | December 31, 2009tags: Corn: The Dynamic Genome, corn, agriculture, genomics, food science, technology, streaming video
This is a beautifully written and produced science video about corn: where it came from, what it originally looked like, the technology we are using to learn the functions of individual corn genes, and future directions for research into corn genetics.
Plant genome research is already revolutionizing the field of biology. Currently, scientists are unlocking the secrets of some of the most important plants in our lives, including corn, cotton and potatoes. Secrets of Plant Genomes: Revealed…
edyong | December 31, 2009If you search for decent definitions of evolution, the chances are that you'll see genes mentioned somewhere. The American Heritage Dictionary talks about natural selection acting on "genetic variation", Wikipedia discusses "change in the genetic material of a population... through successive generations", and TalkOrigins talks about changes that are inherited "via the genetic material". But, as the Year of Darwin draws to a close, a new study suggests that all of these definitions are too narrow.
Jiali Li from the Scripps Institute in Florida has found that prions - the infectious proteins…
razib | December 31, 2009The Properties of Adaptive Walks in Evolving Populations of Fungus:
The rarity of beneficial mutations has frustrated efforts to develop a quantitative theory of adaptation. Recent models of adaptive walks, the sequential substitution of beneficial mutations by selection, make two compelling predictions: adaptive walks should be short, and fitness increases should become exponentially smaller as successive mutations fix. We estimated the number and fitness effects of beneficial mutations in each of 118 replicate lineages of Aspergillus nidulans evolving for approximately 800 generations at…
pharyngula | December 29, 2009Don't miss it! Tonight at 8pmET/7pm Central, NOVA is showing What Darwin Never Knew, a documentary about evo-devo. I shall be glued to my TV tonight!
I just started watching it. So far, it's a nice little history of Darwin and his ideas; Sean Carroll is a good person to have talking up the story. It's nothing new yet, and nothing about evo-devo so far — I'm waiting impatiently for it.
Twenty minutes in, we get a little embryology: limb rudiments in snake embryos, tooth rudiments in whale embryos, and branchial arches in human embryos. These are shown as uncompromising evidence of limbed,…
laelaps | December 29, 2009
During the past year scientists have been celebrating the work of Charles Darwin for the insight the 19th century naturalist had into how evolution works. It is truly amazing how much Darwin got right, but there was also a lot that Darwin didn't know. Indeed, Darwin recognized a group of disciplines that were relevant to what he was proposing, from paleontology to embryology, but despite his discoveries there were still mysteries in each field. A new NOVA program, What Darwin Never Knew, looks at what we now know about some of the questions Darwin's research raised but could not…
edyong | December 28, 2009
In the White Sands National Park of New Mexico, there are three species of small lizard that all share white complexions. In the dark soil of the surrounding landscapes, all three lizards wear coloured coats with an array of hues, stripes and spots. Colours would make them stand out like a beacon among the white sands so natural selection has bleached their skins. Within the last few thousand years, the lesser earless lizard, the eastern fence lizard and the little striped whiptail have all evolved white forms that camouflage beautifully among the white dunes.
Erica Bree Rosenblum from…
grrlscientist | December 27, 2009tags: Birdbooker Report, bird books, animal books, natural history books, ecology books
"How does one distinguish a truly civilized nation from an aggregation of
barbarians? That is easy. A civilized country produces much good bird
literature."
--Edgar Kincaid
The Birdbooker Report is a special weekly report of a wide variety of science, nature and behavior books that currently are, or soon will be available for purchase. This report is written by one of my Seattle birding pals and book collector, Ian "Birdbooker" Paulsen, and is edited by me and published here for your information and…
pharyngula | December 23, 2009
Perhaps your idea of the traditional holiday week involves lounging about with a full belly watching football — not me, though. I think if I did, I'd be eyeing those muscular fellows with thoughts of muscle biopsies and analyses of the frequency of α-actinin variants in their population vs. the population of national recliner inhabitants. I'm sure there's an interesting story there.
In case you're wondering what α-actinin is, it's a cytoskeletal protein that's important in anchoring and coordinating the thin filaments of actin that criss-cross throughout your cells. It's very important in…
laelaps | December 23, 2009
A sample slide from the Your Inner Fish teaching resources.
Just in time for Christmas, paleontologist Neil Shubin has given us a real treat. Neil has composed PowerPoint slides of the illustrations used in each chapter of Your Inner Fish and made them freely accessible to all. I don't have any plans to deliver any classroom lectures in the near future, but if I ever do go back I will definitely make use of them!
pharyngula | December 23, 2009Next Fall, I'll be back in the classroom teaching introductory biology again. One thing I'm planning to do is to use Shubin's Your Inner Fish for that course…and just look what the good man has done just for me: all the figures from the book have been released as powerpoint slides.
OK, he probably didn't think about me at all, and he's releasing them for everyone to use, but still…it's awfully serendipitous.
Grab 'em all, teachers! These are tools for getting more evolution into the biology classroom!
pharyngula | December 22, 2009The lower Congo river is deep and complex, and there are a surprising number of hydrologic features that act as barriers separating populations of fish — this very nice video explains the diversity of species and the ongoing evolution of the fish in this environment.
They too briefly showed a blind depigmented cichlid that apparently lives in very deep troughs in the river — I wanted to see more about that. It's probably out of the question to send divers down into that maelstrom, but cameras? Someday? Please?
awild | December 21, 2009Sorry for an uncharacteristically technical post. But, I've produced an excellent example of a problem that's been plaguing the widely-used phylogenetics program MrBayes and thought it might be of interest to the handful of systematists who read this blog.
I've been running analyses on the Azteca y'all sent after my desperate plea last month and noticed something odd.Â
I set MrBayes to do two runs of 4 chains each. After 10 million generations they produced post-stationarity consensus trees that were topologically identical (that is, the avg. st. dev. splits frequency fell to .005 after…
milhayser | December 21, 2009
Darren Naish inspects "trace fossils" on Tetrapod Zoology, geologic records of footprints and other indentations left behind by animals. Although these telltale signs can "provide excellent information on behaviour and lifestyle," it can sometimes be hard to tell what kind of creature made them in the first place. Such is the case with a set of mysterious parallel grooves preserved in a Jurassic sandbar, which may have been formed by the snouts of ancient sea monsters trolling for snacks. On Laelaps, Brian Switek reconsiders unilinear assumptions of cetacean evolution, citing "a…
edyong | December 21, 2009We're into the home stretch now. This is the seventh of nine polls where you get to pick your favourite stories of the year from this blog. We've had a variety of topics already and today, it's evolution. Your choices:
Robots evolve to deceive one another
How the turtle got its shell through skeletal shifts and muscular origami
Scientists tickle apes to reveal evolutionary origins of human laughter
How diversity creates itself - cascades of new species among flies and parasitic wasps
Museum butterfly collections chronicle evolutionary war against male-killers
Decay of enamel-forming…
grrlscientist | December 20, 2009tags: Birdbooker Report, bird books, animal books, natural history books, ecology books
"How does one distinguish a truly civilized nation from an aggregation of
barbarians? That is easy. A civilized country produces much good bird
literature."
--Edgar Kincaid
The Birdbooker Report is a special weekly report of a wide variety of science, nature and behavior books that currently are, or soon will be available for purchase. This report is written by one of my Seattle birding pals and book collector, Ian "Birdbooker" Paulsen, and is edited by me and published here for your information and…
grrlscientist | December 20, 2009tags: Atheists Can't Think For Themselves!, humor, funny, satire, religion, christianity, islam, Edward Current, streaming video
This astonishing video sets out to prove that being a Christian requires constant thinking, while being an atheist sheep does not. This explains why atheists are the dumbest people God ever created!
awild | December 19, 2009
Camponotus rosariensis tending scale insects in Argentina
Another piece of the Camponotus hyperdiversity puzzle was published this week in BMC Evolutionary Biology. The reasons behind the tremendous richness of Camponotine ants- a worldwide group of conspicuous insects containing more than a thousand species- are unknown, but recent explanations have focused on the nutritional relationship between the ants and their endosymbiotic Blochmannia bacteria. These gut-dwelling microbes may have allowed camponotines to capitalize on honeydew resources nutritionally unavailable to other ants,…
oracknows | December 18, 2009Since I happen to have fallen into the topic of anthropogenic global warming, before I move back to medical topics I might as well have a little fun. Certainly, I could use some, given that I just wrote two posts in which I felt forced to criticize someone whom I admire greatly. Besides, it's been over a week since I last blogged about vaccines on this blog. that has to be some sort of record. Why wreck it now? It feels good to take a break from the topic, and there's always next week. I have no doubt that the anti-vaccine movement will produce something begging for some not-so-Respectful…
razib | December 17, 2009Since my last post was rather pessimistic, I thought I'd point to something a little more cheerful, Social Scientists Build Case for 'Survival of the Kindest':
Researchers at the University of California, Berkeley, are challenging long-held beliefs that human beings are wired to be selfish. In a wide range of studies, social scientists are amassing a growing body of evidence to show we are evolving to become more compassionate and collaborative in our quest to survive and thrive.
In contrast to "every man for himself" interpretations of Charles Darwin's theory of evolution by natural…