evolution
evolvingthoughts | April 3, 2007
Etiology is the study of the causes of things (usually diseases). In my own personal lexicon, etiobiology is the study of the causes and origins of biological processes. Usually, the search term is "origins of life", and recently some new papers have reinvigorated the field.
One is the rerunning of the Miller-Urey experiment done in the 1950s by Stanley Miller. Miller had assumed, based on the work of his advisory, Harold Urey, that the early earth had a reducing atmosphere, in which there is little or no oxygen. This is now thought to be wrong, so some (creationists, OK?) said that…
grrlscientist | March 31, 2007According to this creationist video, peanut butter, which has been subjected to high temperatures to render it sterile, disproves that life can come from non-life. The silliness of this argument reminds me of Kirk Cameron's 'banana proof' of creationism.
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tags: peanut butter, evolution, streaming video
clock | March 31, 2007A review of evo-devo (Jenner, R.A., Wills, M.A. (2007) The choice of model organisms in evo-devo. Nat Rev Genet. 8:311-314. Epub 2007 Mar 6.) is starting to make rounds on the blogs. I cannot access the paper (I'd like to have it if someone wants to e-mail me the PDF), but the press release (also found here) is very vague, so I had to wait for some blogger to at least post a summary.
This is what the press release says (there is more so click on the link):
The subject of evo-devo, which became established almost a decade ago, is particularly dependent on the six main model organisms that…
pharyngula | March 31, 2007I must disagree with Larry Moran, who accuses the field of evo-devo of animal chauvinism — not that it isn't more or less true that we do tend to focus on metazoans, but I disagree with an implication that this is a bad thing or that it is a barrier to respectability. Larry says we need to cover the other four kingdoms of life in greater breadth, which I agree is a fine idea. I would like to have a complete description of the genome of every species on earth, a thorough catalog of every epistatic interaction between those genes during development, a hundred labs working on each species, and a…
grrlscientist | March 30, 2007
120-million-year-old fossilized footprints made by a roadrunner-like bird, Shandongornipes muxiai, discovered in Shandong Province, China. (Track four).
In the past few years, China has become famous for the number and quality of bird fossils from the Early Cretaceous that have been discovered there. This week, another such discovery has been reported by an international team of Chinese, American and Japanese scientists. Their discovery of 120-million-year-old fossilized footprints made by a roadrunner-like bird in Shandong Province, China (see map), was published in the European journal,…
oracknows | March 30, 2007While looking for a birthday card for a relative a while back, I found this card and was intrigued enough to buy it, even though it wasn't appropriate for the person for whom I was seeking a card:
So far, it's just pretty standard Bush-chimp stuff, a staple of comedy ever since W. took office. But what got me was the inside of the card:
Two points:
It's rather amazing that the whole "intelligent design" debate has become so ubiquitous that it's showing up in birthday cards, of all things.
I haven't decided if this is the best birthday card ever or the worst birthday card ever. Opinions?
oracknows | March 30, 2007It is with some trepidation that I approach the latest target of Your Friday Dose of Woo.
No, it's not because the woo is so potent that it has actually struck the fear of You-Know-Who in me (I leave it up to readers to determine whether I was referring to God or Valdemort), although it is indeed potent woo. Nor is it that the woo is boring woo (there's a reason why "power of prayer" kind of woo usually doesn't make it into YFDoW unless there's a really entertaining angle to be targeted). No, it's because this particular woo seems to combine genetics with systems biology (I kid you not),…
evolgen | March 30, 2007Mammals did not rapidly radiate after the K/T boundary.
That's the punch line of a paper published in this week's issue of Nature. This has been all over the news, including the New York Times twice (#1 and #2). You see, there's this idea that when the dinosaurs (technically, the non-avian dinosaurs) disappeared, mammals quickly filled in the vacated niches. That means there should have been a rapid radiation of mammalian lineages following the dinosaur mass extinction -- marked by the boundary between the Cretaceous and Tertiary periods (known as the K/T boundary).
The new study reveals that…
voltagegate | March 30, 2007Mike over at the Questionable Authority has an excellent review of the Nature mammal evolution article I discussed so briefly yesterday.
evolvingthoughts | March 29, 2007
In the very first page to the Origin, Darwin writes:
WHEN on board H.M.S. 'Beagle,' as naturalist, I was much struck with certain facts in the distribution of the inhabitants of South America, and in the geological relations of the present to the past inhabitants of that continent. These facts seemed to me to throw some light on the origin of species - that mystery of mysteries, as it has been called by one of our greatest philosophers.
Who is this greatest philosopher, and what did he mean by that phrase?
I was moved to follow this up when I was challenged on my claim in a forum that…
pharyngula | March 29, 2007I strongly recommend Larry Moran's analysis of the paper on mammalian macroevolution that I briefly described earlier today.
grrlscientist | March 29, 2007
Andrewsarchus was the largest carnivorous land mammal that ever lived.
It lived about 32-60 million years ago. (Image: BBC Walking With Beasts)
Contrary to popular belief, a new study shows that the rise of mammals was not connected to the extinction of dinosaurs that occurred 65 million years ago. The evidence challenging this connection comes from the most complete family tree ever compiled for mammals. This supertree, comprised of genetic and fossil data reveals the relationships between mammals such as primates, rodents and hoofed mammals, including when they evolved into separate…
pharyngula | March 29, 2007The mammalian tree is rooted deeply and branched early!
(click for larger image)All orders are labelled and major lineages are coloured as follows: black, Monotremata; orange, Marsupialia; blue, Afrotheria; yellow, Xenarthra; green, Laurasiatheria; and red, Euarchontoglires. Families that were reconstructed as non-monophyletic are represented multiple times and numbered accordingly. Branch lengths are proportional to time, with the K/T boundary indicated by a black, dashed circle. The scale indicates Myr.
That's the message of a new paper in Nature that compiled sequence data from 4,510…
oracknows | March 29, 2007Apparently the guys over at Denialism.com have irritated Bill Dembski and his band of merry sycophants over at Uncommon Descent. All I can say is: Uncommon Descent, meet the Galileo Gambit. Oh, you've already met the Galileo Gambit, I see.
That must be the explanation for why you do the Galileo Gambit whine so well...
voltagegate | March 29, 2007The tale of our furry ancestors will have to be retold:
U.S. and European researchers are challenging the idea that the mass extinction of dinosaurs played a major role in the evolution of mammals.
The report, published in the journal Nature, contains a new evolutionary tree for mammals that puts the major diversification of today's mammals long after a die-off of the dinosaurs some 65 million years ago.
"We have found that when you fuse all of the molecular trees with the fossil evidence, the timing does not work," University of Georgia Institute of Ecology Director John Gittleman said in a…
mikethemadbiologist | March 29, 2007In response to us foul-mouthed evolutionists, Casey Luskin asks, "Yet for all their numbers and name-calling, not a single one has answered Egnor's question: How does [sic] Darwinian mechanisms produce new biological information?" I've never liked the whole "biological information" concept.
As far as I can tell, the creationists started bandying the term about after this George Gilder article in Wired was published:
Just as physicists discovered that the atom was not a massy particle, as Newton believed, but a baffling quantum arena accessible only through mathematics, so too are biologists…
oracknows | March 29, 2007I was going to try to be a good boy. Really, I was. I had been planning on answering a question about the early detection of tumors. It was an opportune time to do so, given the recent news of cancer recurrence in Elizabeth Edwards and Tony Snow, coupled with a couple of papers I saw just yesterday and the announcement of new screening guidelines for breast MRI. However, I was finding that writing the piece would be fairly complex (because it's a complex topic) and that it might even require a multi-post approach. There was no way to do it justice today; doing it over the weekend would make a…
evolvingthoughts | March 28, 2007
Many ideas in the history of biology get going for reasons that have to do with agendas, ideologies, and plain old bad scholarship rather than the results of research. In particular, myths regarding the motivations of historical figures. I well remember Erik Erikson's execrable attempt to psychoanalyse Luther from a distance of 500 years, culminating in the claim that he was anal retentive (and, therefore, so was his theology).
There are plenty of these myths in the history of biology. One of the longer lasting ones, although it turns out to be a late arrival, is the myth that Darwin didn'…
jlynch | March 28, 2007I don't have time to comment at the moment (perhaps over the weekend), but this looks interesting:
The big dinosaur extinction of 65 million years ago didn't produce a flurry of new species in the ancestry of modern mammals after all, says a huge study that challenges a long-standing theory.
Scientists who constructed a massive evolutionary family tree for mammals found no sign of such a burst of new species at that time among the ancestors of present-day animals...
Instead, they showed an initial burst between 100 million about 85 million years ago, with another between about 55 million and…
razib | March 28, 2007Study Re-evaluates Evolution of Mammals:
Until now, however, most paleontologists had favored a "short-fuse" model in which mammals came into their own almost immediately after the dominant reptiles vacated their habitats. Before the extinctions, most mammals were small nocturnal creatures.
The new study confirmed and elaborated on earlier research by molecular biologists indicating that many of today's mammalian orders originated from 100 million to 85 million years ago. The reasons for this evolutionary burst are not clear.
Drawing on both molecular and fossil data, the researchers said…