evolution
razib | July 20, 2007Update: John Hawks weighs in. Here is the abstract.
Several people have asked about a new paper coming out that uses the diversity in skulls to "prove" the Out of Africa hypothesis. The paper is going to be out in Nature yesterday. Yes, you read that right, it was supposed to be on the site on the 19th, but it still seems embargoed. But here is the headline from ScienceDaily, New Research Proves Single Origin Of Humans In Africa. Press releases are generally a little inflated, so no worries.
The basic gist is that the authors used the variation in skulls to trace population bottlenecks…
scientificactivist | July 19, 2007Yesterday, I mentioned the Atlas of Creation a book by Islamic creationist Adnan Oktar (a.k.a. Harun Yahya) sent unsolicited to scientists around the world. My boss also received a copy a few months ago, and yesterday he dug up the enormous volume for me. My first impression was that it was even larger and more glorious than I remembered. With hundreds of pages of full-color photos, this book must have been incredibly expensive to produce and distribute.
My second impression, though, was that it was also even crazier than I remembered. In the "to the reader" note at the beginning, Oktar…
evolvingthoughts | July 18, 2007
In recent years it has becoming increasingly obvious that there is a considerable amount of lateral, or cross phylogenetic, transfer of genetic material. In bacteria, this happens by several mechanisms, such as uptake of gene fragments from cells that have disintegrated, or by mechanisms such as conjugation ("bacterial sex"). Sometimes genetic material has transferred this way from bacteria into mammal cells. How important this turns out to be for the novelty of evolutionary processes remains to be seen.
But until recently there has been little evidence of lateral transfer (apart from sex…
grrlscientist | July 18, 2007tags: researchblogging.org, flight speed, birds, ornithology, aerodynamics, evolution
Not Bad, But Not Perfect
A peregrine falcon keeps a close eye as she circles her nest in St. Louis.
A new survey of 138 species of birds finds that closely-related birds fly at roughly the same speeds and that no birds are perfect flying specimens.
Image: Tom Gannam (AP) [larger]
When it comes to flight speeds, human-made contraptions, such as airplanes, conform to basic aerodynamic scaling rules, which generate predictions based on how much an object weighs and how large its wings are. However, those…
mikethemadbiologist | July 18, 2007Since I haven't discussed antibiotic resistance for a while, I want to put that health problem in context. The CDC estimates that every year, over 60,000 U.S. residents die from a hospital-acquired bacterial infection that is resistant to one or more commonly used antibiotics. Roughly 25,000 per year die from bacterial infections resistant to three or more antibiotics (e.g., MRSA). And that's just the infections you catch in the hospital. For a little perspective, HIV/AIDS kills under 18,000 U.S. residents per year. Antibiotic resistance is a serious, albeit neglected, problem.
Onto the…
scientificactivist | July 18, 2007A few months ago, my boss (a professor of structural biology at the University of Oxford) received a strange package in the mail, unsolicited. It contained a rather large and colorful book that was quite stunning in appearance. Inside, though, spread across hundreds of color-illustrated pages, was one man's case for creationism: an absurd, unconvincing, misguided, and fundamentally unscientific argument. We passed the book around in the lab, admired its aesthetic values (and the unimaginable expense surely incurred in producing it), and then forgot about it. My boss is out of the lab for…
oracknows | July 18, 2007I really shouldn't do it.
I really shouldn't go perusing the blog of the house organ of the Discovery Institute's propaganda arm, Evolution News & Views, as I did yesterday. I'm not as young as I used to be, have a family history of cardiovascular disease, and am not in the greatest of shape. Reading idiocy such as what regularly appears there surely cannot be good for my blood pressure or my general health, nor can it be good for my mind. Still, for you I nonetheless delve deeply into the muck of logical fallacies, half-truths, distortions, and misinformation that spews forth from the…
clock | July 17, 2007A very interesting new paper was published today in PLoS Biology:
Flight Speeds among Bird Species: Allometric and Phylogenetic Effects by Thomas Alerstam, Mikael Rosen, Johan Backman, Per G. P. Ericson and Olof Hellgren:
Analysing the variation in flight speed among bird species is important in understanding flight. We tested if the cruising speed of different migrating bird species in flapping flight scales with body mass and wing loading according to predictions from aerodynamic theory and to what extent phylogeny provides an additional explanation for variation in speed. Flight speeds…
grrlscientist | July 17, 2007tags: researchblogging.org, birds, ornithology, evolution, radiation, Chernobyl
Normal Barn Swallow (a),
while the other pictures show signs of albinism (white feathers; b & c),
unusually colored feathers (d), deformed beaks (e & f), deformed air sacs (g),
and bent tail feathers (h & i).
Images: Tim Mousseau.
Twenty years after the Chernobyl reactor disaster, which released clouds of radioactive particles in April 1986, the uninhabited forests within the 19 mile (30 kilometer) "exclusion zone" around the disaster site are lush and teeming with wildlife, giving the appearance…
pharyngula | July 17, 2007Why 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
I am so not the right person to review this book—it's like asking Satan to review The Secret. The two aren't even on the same wavelength, and the discombobulated reviewer is going to sit there wondering whether this…
mikethemadbiologist | July 17, 2007Inspired by Quixote's excellent post about ascidians--my firstest study organism EVAH--I've decided to delve into the archives and repost something of my own about ascidians.
I used to study botrylloid ascidians (Botrylloides diegensis to be exact). Ascidians are one of our closest invertebrate relatives. In their larval stage, they look like little tadpoles and even have a notochord (picture taken from here):
Within a few hours, the tadpole settles on a flat surface, and resorbs its tail, and essentially turns itself into a giant pair of vocal chords that are wrapped in mucus. The whole…
voltagegate | July 17, 2007Last time we delved into some of the smallest components of spiders and insects, exploring their differences based on deviations in their genetic code through molecular homology.
But there is one particular unifying element to these creatures and their overall make up. They share a series of genes - sequences of DNA that code for an organism's traits - that determine the exact body plan of an arthropod. These genes, called Hox genes,* have become helpful in describing just how evolution by natural selection constructs each different organism from detailed blueprints within our DNA.
More on…
voltagegate | July 17, 2007Found this in ScienceDaily this morning:
A team of John Innes centre scientists lead by Professor Nick Harberd have discovered how plants evolved the ability to adapt to changes in climate and environment. Plants adapt their growth, including key steps in their life cycle such as germination and flowering, to take advantage of environmental conditions. They can also repress growth when their environment is not favourable. This involves many complex signalling pathways which are integrated by the plant growth hormone gibberellin.
Publishing in the journal Current Biology, the researchers…
grrlscientist | July 16, 2007
A male Blue Moon or Great Eggfly butterfly, Hypolimnas bolina.
A butterfly-killing bacteria that is only lethal to males has given rise to skewed sex ratios in populations of this species on two islands in the South Pacific, but researchers have found that male butterflies on one island have bounced back, thanks to the rise of a suppressor gene. [larger].
In a dramatic demonstration of how quickly evolution can occur, a butterfly species that is found on two adjacent islands in the South Pacific Ocean has rapidly evolved genetic defenses against a bacterial parasite that is lethal only…
grrlscientist | July 16, 2007tags: Attenborough's long-beaked echidna, Zaglossus attenboroughi, monotreme, endangered animals, New Guinea, Irian Jaya, Cyclops mountain range
Attenborough's long-beaked echidna, Zaglossus attenboroughi,
the only specimen known to exist in museum collections.
Prepared as a shmoo (a flat skin lacking most bones).
Image: Natural Museum of Natural History in the Netherlands (NMNH) [larger]
In May of this year, a team of experts from the Zoological Society of London (ZSL) went on a one-month preliminary research expedition to the Cyclops mountain range in Papua on the island of New Guinea.…
razib | July 16, 2007You might not be able to do controlled experiments on humans for evolutionary biological purposes (not only is it unethical, the leisurely rate of human reproduction doesn't make it viable for cranking out Ph.D.s), but you can analyze our pedigrees! Scientific American has a long article, What Finnish Grandmothers Reveal about Human Evolution, about Virpi Lummaa's research program. It's a "sexy" one, I've blogged her research several times, it has pretty deep appeal, focusing on humans & evolution. For you religion haters out there, I do have to point out that it is enabled by the…
voltagegate | July 16, 2007In the last post of this series, we established that spiders descended from marine arthropods called the eurypterids, distinct and separate from insects, appearing in the fossil record in the late Silurian/early Devonian, about 425 million years ago.
The cladogram we used to analyze the spider's history was based on the organism's morphological characteristics, that is, visible structures like chelicerae and book lungs that can be tied to other organisms that possess the same structures. Limulus (the extant horseshoe crab) has both of these structures and predates the spiders, placing them…
evolvingthoughts | July 14, 2007
There has been a bit of a resurgence of science versus religion posts and chatter in various forums* that I inhabit when I'm not working lately. It occurred to me that it might be time to do one of my sermons.
There are basically two popular views of the relation between science and religion. One is the All-Or-Nothing view: science is either entirely subsumed under religion, or totally excluded from it. The other is the view that each has their own special role - Stephen Gould called it the Non-Overlapping Magisterial Authority (NOMA) view. Both are, in my opinion, quite wrong, both…
evolvingthoughts | July 14, 2007
A religious body or faith community that speaks only with only exclamation points but no question marks misses the complexity of creation and the beauty of evolution.
Rabbi Kendall in Stuart, Florida
razib | July 13, 2007Ethiopia unveils new find of ancient fossils:
Ethiopian scientists said on Tuesday they have discovered hominid fossil fragments dating from between 3.5 million and 3.8 million years ago in what could fill a crucial gap in the understanding of human evolution.