evolution
purepedantry | August 17, 2006LTP activated genes are clustered on chromosomes -- or so says some work by Park et al in JBC.
LTP -- or long-term potentiation -- is a process by which synaptic strength -- the ability of one neuron to talk to the next neuron -- is increased by activity. It involves the combination of several processes with different time courses, but some of the best characterized aspects of LTP are genes who transcription is activated by a protein called CREB. CREB is activated during LTP, and CREB activated genes are go on to consolidate LTP at the activated synapse.
There are temporally distinguished…
cmooney | August 17, 2006Well, I just started reading The Politically Incorrect Guide to Darwinism and Intelligent Design. All in all, I find Wells fairly lucid at the beginning of this book and I agree with most of the definitions he offers about what "evolution" is, what "creation" is, and so forth. In short, Wells starts out a lot better than Tom Bethell, his fellow author in the Regnery Politically Incorrect Guides series.
However, I don't agree with the following from Wells' page 8:
...since intelligent design relies upon scientific evidence rather than on Scripture or religious doctrines, it is not biblical…
sporte | August 17, 2006When can a really bad virus be used to do something good?
When we can use it to learn.
The human immunodeficiency virus, cause of AIDS, scourge of countries, and recent focus of ScienceBlogs; like humans, evolves. As one of my fellow ScienceBloggers noted, few biological systems demonstrate evolution as clearly as HIV. In this series, I'm going to guide you through some experiments on HIV evolution that you can do yourself. You won't even have to put on any special clothing (unless you want to), wash glassware or find an autoclave. And, you don't need to any UNIX commands or borrow a…
pharyngula | August 17, 2006Palaeos is gone! There is a brief note about being unable to support it any longer, and then poof, it's offline. Martin Brazeau has a comment on it's value; you can still see fragments of this great resource in google's cache, but even that will fade too soon.
This is troubling, and it's one of the worrisome aspects of using the net—there's no sense of permanence. It would be good if someone were to step forward and at least archive all of the pages, but the essential feature of the Palaeos site was that it was continually maintained and updated to reflect current information, and that's not…
evolvingthoughts | August 16, 2006Razib at Gene Expression has called for a followup to the "evolution in ten words or less" post he previously had and which I responded to (linked in his post above) with a call for "ten assertions about evolution". So I just saw this, and of course I rise to the challenge...
1. All progress in evolution is local. Any longer term trends are either responses to long term environmental changes or stochastic.
2. Natural selection is not evolution (as Fisher said in his Genetical Theory in 1930. Evolution also covers taxonomic diversity, random processes, sexual selection, and so forth.
3.…
clock | August 16, 2006Have you heard about the stupid German study that uses evo-psych Just-So-Stories about, supposedly, women losing interest in sex shortly after marriage?
I wanted to dissect it when it first came out but Real Life and time-constraints prevented me. In the meantime, Dr.Petra, Shakespeare's Sister, Amanda and Echidne ably debunked and destroyed the study and the media reporting on it, so I don't have to do anything but link to them.
cmooney | August 16, 2006Well, summer has been fun, but it's time to get back in business. So I just agreed to debate anti-evolutionist Jonathan Wells on the Alan Colmes Show on Fox Radio, next Tuesday, August 22, from 11:00 to 11:30 ET. Wells, you may or may not know, is author of Icons of Evolution, and now he's got a new one out with Regnery Press (publisher of Tom Bethell) entitled The Politically Incorrect Guide to Darwinism and Intelligent Design. I will be reading his book soon and posting some of its arguments for your reactions...in the meantime, here's where all of you get to tell me I'm crazy for agreeing…
pharyngula | August 16, 2006
Next time you're cutting up a fresh bird, try looking for the lungs. They're about where you'd expect them to be, but they're nestled up dorsally against the ribs and vertebrae, and they're surprisingly small. If you think about it, the the thorax of a bird is a fairly rigid box, with that large sternal keel up front and short ribs—it's a wonder that they are able to get enough air from those tiny organs with relatively little capability for expanding and contracting the chest.
How they do it is an amazing story. Birds have a radically effective respiratory system that works rather…
loom | August 16, 2006The textbook explanation of DNA goes something like this: enzymes in our cells read a stretch of DNA and convert its code into a single-stranded RNA molecule, which is then used by ribosomes as a template for building a protein. That stretch of DNA biologists call a gene. The protein it encodes drifts off to do some job--building cell membranes, maybe, or switching off other genes, and so on.
This is a fairly accurate picture--for less than two percent of the human genome. The rest of our DNA does not encode proteins. Much of it may be made up of genetic material from viruses and disabled…
pharyngula | August 16, 2006Zimmer has a summary of the latest discoveries in the evolution of the baleen whales. It's beautiful stuff, with the lineage showing their origin from toothed whales, through a phase where they had both teeth and baleen, to their current condition lacking teeth and having only baleen.
evolgen | August 16, 2006There is a good biography of Ernst Mayr in the upcoming issue of Theoretical Population Biology. The author, Eviatar Nevo, provides both a summary of Mayr's work and distills his contributions into categories. I especially like how he explains Mayr's understanding of evolution (which he calls Darwinism, much to my chagrin) into five sub-theories:
For Mayr, a full understanding of the autonomy of biology is impossible without an analysis of Darwinism. Modern biology is conceptually Darwinian to a large extent. Mayr summarized this conceptual insight by showing that Darwinism basically embraces…
evolvingthoughts | August 15, 2006The Christian Science Monitor has a reasonable review of David Quammen's latest book, The Reluctant Mr Darwin, but there are a couple of interesting tells.
One of my pet hates is this sort of journalistic boilerplate:
Centuries before, Copernicus removed the Earth from the center of the universe; now Darwin had removed man as "God's chosen" among life forms.
First of all, Copernicus did not dethrone the Earth from the center of the universe. He elevated it to the same high status of the heavens, which was what people objected to. Prior to that, the Earth was the universe's garbage dump, where…
evolvingthoughts | August 15, 2006Occasionally one comes across odd stories in the late medieval literature on natural history, and one is inclined to dismiss them as fablous stories born of credulous superstition. But they illustrate a much more important phenomenon - the shift from seeing nature as a source of moral lessons to seeing nature as something worth studying for its own sake. One such is the tale of the Barnacle Goose.
The Barnacle Goose, Branta leucopsis, is a small (less than 2kg) black and white goose of the order Anseriformes. It lives during the winter months in the Atlantic coasts of Scotland and Ireland,…
loom | August 15, 2006Whales are beautifully ridiculous. They are majestic divers, in some cases plunging nearly two miles underwater. And yet sooner or later they must rise back to the surface to breathe air. They breathe through a rather ridiculous-looking hole on top of their head. Unlike fish, which often reproduce by spraying millions of eggs and swimming away, whales give birth to one calf at a time, which they proceed to nurse for months. Some whales are like underwater bats, shrieking through their blowholes and listening to the echoes. And perhaps most ridiculous of all are whales that turn themselves…
scientificactivist | August 15, 2006Since I've been on the road so much lately, I haven't really had a chance to follow up on some of the more interesting links forwarded to me lately. Each probably deserves its own post... but I'm going to dump them all into this post anyway. Besides, there seems to be a common thread running through all of them.
First up is an interview with climate scientist Ben Santer in Environmental Science & Technology. Santer was a lead author on the president's recent Climate Change Science Program (CCSP) and has been a target of anti-environmental groups since he was a lead author on a 1995…
clock | August 15, 2006Archy is on top of the story, as usual when the story is about people trying to resurrect mammoths!
evolgen | August 14, 2006Razib wants us to come up with 10 assertions of 10 words or less which we believe that the public should know about evolutionary science. He also wants us to come up with our list before looking at his list, which means we're left to figure out what the hell he means without seeing any examples. My stab at this is below the fold, but you should come up with your own list before reading Razib's or mine (according to Razib).
10 Assertions about Evolution, in no particular order:
Common ancestry is supported by multiple, independent lines of evidence.
Evolution is not an entirely random…
razib | August 14, 2006My post asking to define evolution in less than 10 words elicited a lot of response (some of it outside the parameters I set in regards to length). So I figured I'd give this sort of thing another shot, again, with parameters which all are welcome to violate, but which I set for myself to prune my tendency toward qualifying verbosity. Below the fold are "10 assertions of 10 words or less" which I believe that the public should know about evolutionary science. I did this in 3.5 minutes, typing out what came to mind and checking word count in M$ Word. Obviously the assertions reflect my…
evolvingthoughts | August 13, 2006Just saw this link at The Unofficial Stephen Jay Gould archive. Eldredge was Gould's collaborator on punctuated equilibrium theory, and is a deep thinker about matters evolutionary. It contains discussions of many topics - go check it out.
razib | August 13, 2006Dienekes points me to a new paper in Science which purports to add an archaeological layer of data to the "Out of Africa" paradigm which initially burst onto to the scene in the 1980s due to the molecular clock & mtDNA (though Chris Stringer and others long argued for a form of "Out of Africa" based purely on fossil morphology). The Independent has a good summary of the major points. The short of it is that this paper seems to suggest
a) One major Out of Africa event via the "Southern Route" (i.e., along the coast of southern Eurasia out of East Africa)
b) Subsequent radiations from…