evolution
razib | October 28, 2009There's something cool about Canada, I just found out that Alberta is the only large region of permanently inhabited human territory which lacks brown rats. One thing you have to remember is that the brown rat only began spreading within the last 1,000 years (in the process displacing the black rat), and it seems to have arrived in the British Isles only within the last two to three centuries. North America did not have the rat until Europeans arrived, and it didn't show up in Alberta until 1950. At that point the government attempted an eradication program. Apparently this can work because…
sb admin | October 28, 2009
Oliver Morton wrote a delightful book all about photosynthesis called Eating the Sun: How Plants Power the Planet, which I reviewed earlier this year for Search Magazine (R.I.P.) under the title "A Song for the Heartless". One of my favorite passages in the book beautifully explains the difference between art and science:
Discoveries feel determined. They are there to be made, and if one person doesn't, another will. This doesn't lessen the achievement; indeed it can give it spice. The thought that 'this is the way the world is--and I am the first to see it as such' is an intoxicating…
pharyngula | October 28, 2009I'm liking these CreatureCast videos from Casey Dunn — I showed the first in this series, now here's the second. It uses very simple animation to illustrate basic concepts…like the evolution of multicellularity in this one.
CreatureCast Episode 2 from Casey Dunn on Vimeo.
laelaps | October 28, 2009
Skeletons of the early horse-relative Eohippus (left) and modern Equus (right). From Animals of the Past by Lucas.
During the early 20th century many biologists were considering a variety of mechanisms other than natural selection as the primary cause of evolutionary change. The trouble was that many of those researchers were often vague when it came to the details of how such alternative processes might work. Such was the case with paleontologist Frederic Augustus Lucas, who apparently preferred to think of evolution as variations stimulated by the environment building upon themselves…
razib | October 27, 2009Dr. Thomas Mailund has posted a YouTube interview of Svante Paabo. Looks like the previous post was off-base, though I'm not really totally sure.
pharyngula | October 27, 2009Why? Because Jerry Coyne can mention this amazing conference, I can take a look at the luminaries speaking at it, and decide at the drop of a hat that I'm going. So this weekend, I'll be spending my Halloween at a major conference on evolution. Yay!
Look forward to lots of liveblogging (I hope…if they have wi-fi in the conference halls. If not, there will be some massive data dumps in the evenings.)
razib | October 27, 2009My co-blogger at Gene Expression Classic, David, has completed a very interesting series today.
1: The Pattern of Evolution
2: Mechanisms of Evolution
3: Heredity
4: Speciation
5: Gradualism (A)
6: Gradualism (B)
7: Levels of Selection
laelaps | October 27, 2009
An American mastodon, Mammut americanum, from F.A. Lucas' Animals Before Man in North America.
Throughout high school and college I was taught the same thing about the history of science. Young earth creationists had a stranglehold on explanations for life's origins until the fateful year of 1859 when Charles Darwin convinced all but the most ardent fundamentalists that evolution by means of natural selection was a reality. It is a neat and tidy story, a tale in which one book changes the world forever, and it is completely wrong.
As I started to dig deeper into the history of science I…
razib | October 26, 2009Neanderthals 'had sex' with modern man:
Professor Svante Paabo, director of genetics at the renowned Max Planck Institute for Evolutionary Anthropology in Leipzig, will shortly publish his analysis of the entire Neanderthal genome, using DNA retrieved from fossils. He aims to compare it with the genomes of modern humans and chimpanzees to work out the ancestry of all three species.
...
Paabo recently told a conference at the Cold Spring Harbor Laboratory near New York that he was now sure the two species had had sex - but a question remained about how "productive" it had been.
"What I'm…
edyong | October 25, 2009The most incredible eyes in the animal world can be found under the sea, on the head of the mantis shrimps. Each eye can move independently and can focus on object with three different areas, giving the mantis shrimp "trinocular vision". While we see in three colours, they see in twelve, and they can tune individual light-sensitive cells depending on local light levels. They can even see a special type of light - 'circularly polarised light' - that no other animal can.
But Nicholas Roberts from the University of Bristol has found a new twist to the mantis shrimp's eye. It contains a…
grrlscientist | October 25, 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…
awild | October 22, 2009
A sampling of face patterns in Polistes fuscatus paper wasps
Polistes fuscatus paper wasps sport a bewildering array of facial markings. Why is this?
A new paper by Michael Sheehan and Elizabeth Tibbetts in the journal Evolution suggests natural selection may favor rare patterns, leading to a proliferation of diversity. Sheehan & Tibbetts performed an elegant experiment on 18 groups of 4 foundress queens, painting three wasps with one pattern and the remaining one with a different pattern. Regardless of the details of the actual face markings, the rare pattern consistently…
edyong | October 22, 2009By directing the evolution of a worm, scientists have confirmed answers to the age-old question: "What is the point of having sex with someone else?" For most people, that would hardly be a tricky query but it's no reflection on the lives of evolutionary scientists that sex has been one of biology's oldest puzzles.
The problem is this: many creatures can reproduce by fertilising themselves instead of getting someone else to do it, and at first glance they should do much better individuals that cross-fertilise. For a start, they'd ensure that all of their genes reach the next generation,…
razib | October 22, 2009If you have more than a marginal interest in evolutionary biology you will no doubt have stumbled upon the conundrum of sex & sexes. Matt Ridley's most prominent work, The Red Queen: Sex and the Evolution of Human Nature, covered both the theoretical framework and applied implications of the subject. Ridley leaned heavily upon William D. Hamilton's scientific work, which extended upon Leigh Van Valen's concept of the book's titular Red Queen. The complex interplay between pathogens & multicelluar organisms across the eons is a topic of such breadth and depth that a substantial…
laelaps | October 21, 2009
The restored lower jaw of Afradapis. From the Nature paper.
This past May a 47 million year old fossil primate named Darwinius masillae, better known as "Ida", burst onto the public scene. The lemur-like creature was proclaimed to be the "missing link" and the "ancestor of us all", but the actual science behind Ida was drowned by a tide of media sensationalism. Press releases and documentaries proclaimed that Ida would "CHANGE EVERYTHING", but despite such promises the sky remained blue, my cats continued to wake me up at 5:30 AM, and the primate evolutionary tree did not suddenly…
edyong | October 21, 2009Cast your mind back to June, when a stunning fossil animal called Darwinius (alternatively Ida or "The Link") was unveiled to the world to tremendous pomp and circumstance. Hyperbolic ads declared the day of Ida's discovery as the most important for 47 million years. A press release promised that she would "change everything", headlines proclaimed her a "missing link in evolution" and the scientists behind the discovery billed her as "the closest thing we can get to a direct ancestor".
And according to a new study, none of that is true. Mere months later, Erik Seiffert from Stony Brook…
ejohnson | October 21, 2009On October 1, 2009 paleontologists announced the discovery of the oldest known primitive hominid fossil, Ardipithecus ramidus dubbed "Ardi," after 17 years of quietly studying its significance. Nearly a month after its grand unveiling to the media, biologists, paleontologists, and evolutionary anthropologists are still atwitter as scores of articles continue to be published around Ardi. ScienceBloggers are no exception this week, beginning with Razib Khan's compelling conversation on Ardi with John Hawks on Bloggingheads.tv, as seen on Gene Expression. On The Primate Diaries, Eric Michael…
razib | October 21, 2009One of the banes of modern life is the stack of papers in one's "to-read" list. I guess that goes to show how cushy modern life is, as what sort of complaint is that? In any case, I began to consider this after reading Joe Thornton's magisterial response to Michael Behe's giddy excitement over his most recent paper, An epistatic ratchet constrains the direction of glucocorticoid receptor evolution. Thornton dispatches Behe's muddled misconceptions with economy and precision, but after reading the paper, as opposed to cogent summaries such as Carl Zimmer's in The New York Times I'm even more…
edyong | October 20, 2009In the forests of South Africa lurks an arachnophobe's nightmare - Nephila kowaci, the largest web-spinning spider in the world. The females of this newly discovered species have bodies that are 3-4 centimetres in length (1.5 inches) and legs that are each around 7.5cm long (3 inches).
This new species is the largest of an already massive family. There are 15 species of Nephila - the golden orb weavers - and at least 10 of them have bodies that are over an inch long. Many spin webs that are over a metre in diameter.
The first of these giants was discovered by Linnaeus himself in 1767 and…
pharyngula | October 20, 2009Yesterday, I got a brief mention of a botch of a radio show on NPR that nattered on about a "deep rift" in atheism, but this morning on MPR you could have heard Richard Dawkins talking about evolution. He got the better gig.
This interview does make clear one difference in strategy between Dawkins and myself. The interviewer tries to hammer him on being less than respectful to religious believers, and Dawkins is always polite and tries his best to downplay the conflict. In a similar situation, I'd simply say, "Yes, I am openly contemptuous of religious belief. You want to make something of it…