evolution
razib | May 21, 2009A few years ago I commented a fair amount on the topic of prosopagnosia, face blindness. Turns out that ~2% of the population can't really recognize faces, and this is a cryptic trait as many of these individuals have developed compensatory tendencies so that people don't know. Not only that, but there seems to be a strong genetic component so that it runs in families. At the time I was fascinated by this because it made me wonder at how much more "cryptic" variation there could be in the human population. It seems that face recognition is such a basic and universal "competency" that it is…
edyong | May 21, 2009In the forests of South America lives the unusual but aptly named owl monkey, or douroucouli. You could probably guess by looking at its large round eyes that it's nocturnal, and indeed, it is the only monkey to be mostly active at night. But its eyes have many adaptations for such a lifestyle, beyond a large size.
The owl monkey's retinas are 50% larger than those of a day-living monkey of similar size, like the brown capuchin. The proportions of different cells in their retina are also different. Owl monkeys have relatively few cone cells, which are responsible for colour vision and fewer…
mikethemadbiologist | May 20, 2009While I'm away at ASM, here's something from the archives for you
When I read Olivia Judson's post about hopeful monsters, I didn't think she used the term correctly (here are some good explanations why), but I was surprised by Jerry Coyne's response.
First, the personal attack on Judson is unwarranted: when we reach the point where the serious challenge to evolutionary biology is the misuse of a discredited decades-old idea, as opposed to the politically powerful anti-science creationist movement, we're in a pretty good place. She made a mistake--I don't think her motives were self-…
edyong | May 20, 2009Yesterday, the entire world changed noticeably as the media, accompanied by some scientists, unveiled a stunning fossilised primate. The creature has been named Darwinius masillae, but also goes by Ida, the Link, the Chosen One and She Who Will Save Us All.
The new fossil is remarkably complete and well-preserved, although the media glossed over these facts in favour of the creature's ability to cure swine flu. Ida was hailed as a "missing link" in human evolution, beautifully illustrating our transition from leaping about in trees to rampant mass-media sensationalism.
Speaking to a group…
evolvingthoughts | May 19, 2009In addition to the "missing link" trope that is being dished out about the new primate fossil, is another one, more subtle and insidious: it's the ancestor of all primates. How do they know that? Consider a biologically realistic scenario: at the time there were probably hundreds of species of small bodied mammals with tails and feet like that. One of these species may be the ancestor of all primates, but what are the odds that a specimen from that species is the one that was preserved? Just as all primates now look remarkably similar overall, but one may be the common ancestor of a group in…
razib | May 19, 2009You'll be seeing a lot of media hype about a new paper, Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology. Here's some perspective, A Discovery That Will Change Everything (!!!) ... Or Not and There is no missing link. Bora has just about every commentary on this paper in his link list....
pharyngula | May 19, 2009This is an important new fossil, a 47 million year old primate nicknamed Ida. She's a female juvenile who was probably caught in a toxic gas cloud from a volcanic lake, and her body settled into the soft sediments of the lake, where she was buried undisturbed.
What's so cool about it?
Age. It's 47 million years old. That's interestingly old…it puts us deep into the primate family tree.
Preservation. This is an awesome fossil: it's almost perfectly complete, with all the bones in place, preserved in its death posture. There is a halo of darkly stained material around it; this is a remnant of…
clock | May 19, 2009Another super-cool day at PLoS (one of those days when I wish I was not telecommuting, but sharing in the excitement with the colleagues at the Mothership) - the publication of a very exciting article describing a rarely well-preserved fossil of a prehistoric primate in a lineage to which we all belong as well:
Complete Primate Skeleton from the Middle Eocene of Messel in Germany: Morphology and Paleobiology by Jens L. Franzen, Philip D. Gingerich, Jörg Habersetzer, Jørn H. Hurum, Wighart von Koenigswald and B. Holly Smith
The fossil, named Ida (the scientific name is Darwinius masillae, a…
evolvingthoughts | May 18, 2009One of the problems that many people have with evolution is not religious, but philosophical. If evolution is true, they think, then we are at sea - nothing is fixed, nothing is determinate, all coherence is gone, as Donne famously lamented of the death of the two-sphere universe and physics. This is, I believe, a valid worry. But it is not new or due to evolution: Heraclitus worried about it, as did Parmenides, and the solutions given by Plato and Aristotle against the atomists were in effect ways to deny that what really counted was changing. They called change "degeneration" or "corruption…
evolvingthoughts | May 18, 2009The wonderful Project Gutenberg has just released a fully HTMLised version of R. C. Punnett's (he of the famous "square") 1911 book Mendelism, which shows how quickly the implications of Mendelian genetics, rediscovered 11 years earlier, were worked through. It's a wonderful read, and anyone with a slight knowledge of biology and the interest to work through the examples can understand it, something one cannot say of texts on science for very much longer after this. I was particularly interested in the following passage, from page 150:
One last question with regard to evolution. How far does…
razib | May 18, 2009Ed Yong has an excellent review of new research which casts substantial doubt on the trivia chestnut that Komodo dragons kill their prey with their extremely pathogen rich saliva. The more prosaic answer seems to be that they utilize poison, not particularly surprising or trivia worthy for a reptile. But the truth is not always sexy.
ddobbs | May 18, 2009
A ring-tailed lemur, via Afarensis
Here's one that'll grab you. Via Discover's 80beats science news blog:
A small, lemur-like creature may have been an early ancestor of monkeys, apes, and humans. A magnificently preserved fossil dating from 47 million years ago reveals an animal that had, among other things, opposable thumbs, similar to humans', and unlike those found on other modern mammals. It has fingernails instead of claws. And scientists say they believe there is evidence it was able to walk on its hind legs [ABC News].
This from a study to be published in PLoS ONE tomorrow, and which…
pharyngula | May 18, 2009I've been reading a new book by Jack Horner and James Gorman, How to Build a Dinosaur: Extinction Doesn't Have to Be Forever(amzn/b&n/abe/pwll), and I was pleasantly surprised. It's a book that gives a taste of the joys of geology and paleontology, talks at some length about a recent scientific controversy, acknowledges the importance of evo-devo, and will easily tap into the vast mad scientist market.
It is a little scattered, in that it seems to be the loosely assembled concatenation of a couple of books, but that's part of the appeal; read the chapters like you would a collection of…
grrlscientist | May 17, 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…
jstemwedel | May 16, 2009Dear Natural Selection,
Can we have a chat about weeds?
Don't get me wrong, I am duly impressed with the variety of plants that have evolved under your pressure. I'm all about the plants, and I try to be respectful of the growing conditions you impose in our zone.
But would it kill you to make more of the plants that grow like gangbusters without us tasty? Why can't they all be like mint and lemon balm?
Sure, yeah, if the weeds were tasty, it would be hard for them to defend themselves against being eaten. But I promise we're not drinking mojitos every night at Casa Free-Ride. And if the…
evolvingthoughts | May 16, 2009Chris Nedin has another post of great interest (even if it is for a late period, the Pleistocene) which goes into my file of "the older naturalists were great observers", as he shows how modern chemistry supports Richard Owens' diagnosis of Thylacoleo as a carnivore, even though it is in a clade of herbivores.
grrlscientist | May 15, 2009tags: evolutionary biology, AMNH, American Museum of Natural History, New York City, mammals, biodiversity
Because I write for ScienceBlogs, I have been invited to a special sneak preview of the "Extreme Mammals" exhibit hosted by the American Museum of Natural History, where I was a postdoctoral fellow for two years. This exhibit features the biggest, smallest, most amazing and generally the weirdest mammals to ever swim, fly or walk the face of this earth. "Extreme Mammals" opens to the public on Saturday, 16 May, but my goal is to take a lot of photographs to share with you here this…
jrosenhouse | May 13, 2009Jerry Coyne has a post up on the subject of whether a highly-intelligent, self-aware species is the inevitable end result of the evolutionary process. He begins:
Over at that hilarious goldmine of accommodationism, Francis Collins's BioLogos website (generously supported by The Templeton Foundation), they have posted an answer to the question, “Did evolution have to result in human beings?” Now if you know anything about this history of faith/science accommodationism, you know that the answer has to be “yes”, at least if you construe the question to mean “Did evolution have to result in a…
awild | May 13, 2009One of the most vociferous debates in taxonomy is over a catchy-sounding concept called DNA barcoding. Since nearly all organisms carry a version of the COI gene in the mitochondrion, the idea is that the DNA sequence of the gene can serve as a standard identification marker. A barcode, of sorts. Of course, the practice only works if species have unique COI sequences. Which they do, much of the time, and the barcoders consequently have been successful in garnering research money and churning out publications.
So what's the problem?
There are two major objections. The first is…
edyong | May 12, 2009In Mexico's Cueva del Azufre (the Sulphur Caves), a small fish called the shortfin molly (Poecilia mexicana) is on the way to becoming two separate species. Those that live in the dark interior of the caves are very different to their relatives that swim in the bright, surface waters. They have lighter colours and live more solitary lives. Their eyes are smaller, less sensitive and have lower levels of light-sensitive pigment. Instead, they rely instead on a hypersensitive pressure detector - the lateral line - to sense disturbances in the water.
Their differences aren't just skin deep…