evolution
oracknows | July 18, 2006Over the weekend, between bouts of rounding on patients and seeing consults (I was on call), I perused the Last 24 Hours channel on the ScienceBlogs homepage, when I came across a fellow SB'er discussing a recent paper in Science about evolution. It was a study of the finches of the Galapagos Islands by Princeton evolutionary biologists Peter and Rosemary Grant. Being a physician and not a hardcore evolutionary biologist, I must confess that I don't always get into the nitty-gritty of how biologists study evolution, but this was a compelling story that was fairly easy for me to understand. I…
pharyngula | July 18, 2006
Carl Zimmer wrote on evolution in jellyfish, with the fascinating conclusion that they bear greater molecular complexity than was previously thought. He cited a recent challenging review by Seipel and Schmid that discusses the evolution of triploblasty in the metazoa—it made me rethink some of my assumptions about germ layer phylogeny, anyway, so I thought I'd try to summarize it here. The story is clear, but I realized as I started to put it together that jeez, but we developmental biologists use a lot of jargon. If this is going to make any sense to anyone else, I'm going to have to step…
cmooney | July 17, 2006Dude, I fricken love that Chuck Darwin is on the ten pound note.
Also, I saw a fox this morning while jogging in Hyde Park. And these birds: Greylag Goose, Grey Heron, Blackbird, Black-headed Gull, Carrion Crow (probably), Tufted Duck (I think), Great Crested Grebe, Lesser Black Backed Gull (probably), Magpie, Mute Swan, Woodpigeon, and unidentified others. From a birding perspective, you might remark that I am really gathering the low-hanging fruit here. But since the last time I was in London was nearly ten years ago, and I was not then a birder, I never noted any of these suckers down…
purepedantry | July 17, 2006God is so tricky. New research reveals that the structure of a DNA replication molecule is similar across all three domains of life:
In two papers that will be concurrently published in the August edition of the journal Nature Structural and Molecular Biology (now available on-line), the researchers report the identification of a helical substructure within a superfamily of proteins, called AAA+, as the molecular "initiator" of DNA replication in a bacteria, Escherichia coli (E. coli), and in a eukaryote, Drosophila melanogaster, the fruit fly. Taken with earlier research that identified AAA…
jlynch | July 17, 2006This story in the Times of London (breathlessly titled "How man's best friend overcame laws of natural evolution"*) has been linked to by Dembski over at his blog and by a number of other creationists around the web. I guess they think it somehow disproves evolution or problematizes natural selection. It discusses an article in Genome Research which used mtDNA analysis to examine selection in dogs and wolves and notes (according to the article) that natural selction
was relaxed when dogs became domesticated. Living with people allowed harmful genetic variations to flourish that would never…
neurotopia | July 17, 2006A new website in the fight against the ID movement's attempted takeover of the Kansas state science standards. Check it out. Nick Matzke has more here.
jrosenhouse | July 17, 2006Mark Chu-Carroll joins the discussion with this interesting post.
But if you look at my writing on this blog, what I've mainly done is critiques of the IDists and creationists who attempt to argue against evolution. And here's the important thing: the math that they do - the kind of arguments coming from the people that Luskin claims are uniquely well suited to argue about evolution - are so utterly, appallingly horrible that it doesn't take a background in evolution to be able to tear them to ribbons.
To give an extreme example, remember the infamous Woodmorappe paper about Noah's ark?…
loom | July 17, 2006If our genes are wired like circuits, does that mean nature is an electrician?
One of the most important sorts of jobs that genes do is to switch other genes on or off. The classic example comes from Escherichia coli, and how it eats milk. (I'm afraid Escherichia coli will be progressively infecting this blog in the months to come, as I finish my new book on this remarkable bug.) Escherichia coli can make the enzymes necessary for digesting lactose, the sugar in milk. But it normally doesn't, because it makes proteins that clamp onto its DNA next to these genes and prevent gene-reading…
clock | July 17, 2006This post about the origin, evolution and adaptive fucntion of biological clocks originated as a paper for a class, in 1999 I believe. I reprinted it here in December 2004, as a third part of a four-part post. Later, I reposted it here.
III. Whence Clocks?
Origin, Evolution, and Adaptive Function of Biological Clocks
The old saw about the early bird just goes to show that the worm should have stayed in bed. (Heinlein 1973)
Now darkness falls.
Quail chirps.
What use Hawk eyes?
(Basho)
Local/temporary and global/universal environments. In the study of adaptive functions, usually the question…
pharyngula | July 17, 2006
Do vertebrate embryos exhibit significant variation in their early development? Yes, they do—in particular, the earliest stages show distinct differences that mainly reflect differences in maternal investment and that cause significant distortions of early morphology during gastrulation. However, these earliest patterns represent workarounds, strategies to accommodate one variable (the amount of yolk in the egg), and the animals subsequently reorganize to put tissues into a canonical arrangement. Observations of gene expression during gastrulation are revealing deeper similarities that are…
clock | July 16, 2006Do you read Darren Naish's blog Tetrapod Zoology? If not, you should start now. Just check out some of the most recent posts, for example this two-parter on sea snakes: 'A miniature plesiosaur without flippers': surreal morphologies and surprising behaviours in sea snakes and Sea kraits: radical intraspecific diversity, reproductive isolation, and site fidelity.
Or, this two-part post about the importance of the shape of the birds' bills: The war on parasites: a pigeon's eye view and The war on parasites: an oviraptorosaur's eye view.
Or an amazing four-part story about Angloposeidon, a…
jrosenhouse | July 15, 2006In Part One of this essay I discussed my answer to the question of whether mathematicians were qualified to discuss evolution. The inspiration for these musings was this post, from Discovery Institute blogger Casey Luskin.
We now pick up the action in the second paragraph of Luskin's post:
The truth is that mathematics has a strong tradition of giving cogent critique of evolutionary biology. After all, Darwin's theory of evolution by natural selection is fundamentally based upon an algorithm which uses a mathematically describable trial and error process to attempt to produce complexity.…
neurotopia | July 15, 2006Kent, the gift that keeps on giving. Man, is anybody affiliated with Hovind NOT a crook?
neurotopia | July 14, 2006Last weekend there was an article in the Wichita Eagle on the situation with the Kansas BoE. Since creationists can't get their tripe published in real science journals, but instead have to rely on popularity contests elections in order to pass their shit off as reality to our kids, I thought I'd dig up one of my old posts.
Here's the a grand example of why science is not determined by consensus.
If you live in Kansas, The TruthTM which your children are taught in school is decided based upon the ideology of the current Board of Elections. This coming year, for example, Intelligent Design…
jrosenhouse | July 14, 2006Via Gene Expression I came across this post, at the Discovery Institute's blog, from erstwhile ID lackey Casey Luskin. It's title: Mathematicians and Evolution. Hmmmm. Sounds like something I should read.
Luskin writes:
As recently highlighted here, mathematics is an academic locale where scientific skepticism of Neo-Darwinism can survive the current political climate! Discovery Institute recently received an e-mail from someone commenting on the Scientific Dissent from Darwinism List where over 600 Ph.D. scientists from various fields agree that they are “skeptical of claims for the…
hrynyshyn | July 14, 2006Anyone want to take a run at anticipating the reaction from creationists to the news that "Finches on Galapagos Islands [are] Evolving" (Associated Press, July 14)? I'm thinking they will latch onto the story's first paragraph, which ever so slightly introduces a microscopic degree of uncertainty into the most powerful unifying principle in biology.
I don't fault reporter Randolph E. Schmid or his editors. They're writing for the general public, so it makes sense to lead off a story on evolution thusly:
WASHINGTON -- Finches on the Galapagos Islands that inspired Charles Darwin to develop the…
purepedantry | July 14, 2006Apparently today will be poetry day. I found this poem in a book I was reading. It is by a man named Mortimer Collins (1860):
Life and the Universe show spontaneity:
Down with ridiculous notions of Deity!
Churches and creeds are all lost in the mists;
Truth must be sought with the Positivists.
Wise are their teachers beyond all comparison,
Comte, Huxley, Tyndall, Morley and Harrison.
Who will venture to enter the lists
With such a squandron of Positivists?
There was an ape in the days that were earlier;
Centuries passed and his hair became curlier;
Centuries more gave a thumb to his wrist…
pharyngula | July 13, 2006Yesterday, I reposted an article on homology within the neck and shoulder, which describes an interesting technique of using patterns of gene expression to identify homologous cellular pools; the idea is that we can discern homology more clearly by looking more closely at the molecular mechanisms, rather than focusing on final morphology and tissue derivation. Trust me, if you don't want to read it all—it's cool stuff, and one of the interesting points they make is that they've traced the fate of a particular bone not found in us mammals, but common in our pre-synapsid ancestors, the…
loom | July 13, 2006Randy Olson visited the Loom a few months ago in connection with his movie about our national fun and games with evolution and intelligent design, Flock of Dodos. He provoked a lot of discussion with his main point, that biologists were doing a poor job of reaching out to the public. Some skeptics wondered whether accepting Olson's argument would lead to dumbing science down and engaging in the same bogus PR as creationists. This morning Randy dropped me an email note to point out what he considers a depressing confirmation of his thesis.
Kansas--where the science standards have been…
scientificactivist | July 13, 2006This week's Nature features a news article and editorial about Francis Collins--director of the US National Human Genome Research Institute--whose new book The Language of God advocates reconciliation between science and religion. Although the status of science in America could be improved by lessening religious anti-science hostility, and we're generally much better off in general when we all get along, the argument advanced by Collins is less than compelling.
To his credit, Collins' religious views are relatively progressive, and he disagrees strongly with creationism and intelligent…