ChicagoDarwin2009
pharyngula | October 31, 2009Man, philosophers sure take a long time to get to the point.
OK, his outline: 1) development and differential entrenchment in evolution. 2) application of these principles to culture. 3) what new phenomena this theory can capture.
Plunges into "thick, thin, and medium viscosity theories of culture". I have no idea what he's talking about: I hope he'll get into some specifics I can grapple with soon, because right now this is just a wall of words.
Any evolving system must meet Darwin's principles: variation, which is heritable, which has consequences on fitness. Wimsatt suggests two additional…
pharyngula | October 31, 2009Darwin didn't know the basic mechanisms of evolutionary change. Mechanism of inheritance was a black box. Darwin's last publication before his death was "on the dispersal of bivalves". Why are freshwater bivalves so homogeneous in morphology? Describes a beetle with a conch attached to its leg, which provided a mechanism of dispersal. Turns out the specimen was sent to Darwin by Crick's grandfather.
How is variation generated and maintained in natural populations? What genes matter? What will finding the genes tell us?
We find genes underlying phenotypic diversity by comparison of highly…
pharyngula | October 31, 2009How can I resist an opportunity to see Ruse gibbering on the stage? I'm curious to see whether he annoys or enlightens. It could go either way.
He's not going to talk about evo-devo! OK, I'm already annoyed.
Criticizes the infamous New Scientist cover, "Darwin Was Wrong"; received email from Paul Nelson (boo) claiming the edifice of darwinism is crumbling; Rudy Raff has written that evolution requires development to remain relevant. Are today's evolutionists genuinely Darwinian or not?
Plans to pick on something that was self-consciously in Darwin's thinking. Darwin became an evolutionist in…
pharyngula | October 31, 2009Shubin had a tough act to follow, coming after Kingsley's great talk. I'm sure it will be good, though — last night I got a tour of his lab, saw the original Tiktaalik specimens and some new ones, and some of his work in progress (which I won't tell you about until it's published), so I'm confident I'm going to have a happy hour.
Darwin pulled together diverse lines of evidence to document his ideas. The different lines all reinforce each other making the argument even stronger, and what we're seeing now is new syntheses, which is the theme of this talk: how do we use different lines of…
pharyngula | October 31, 2009Jerry Coyne has put up a few photos from the conference, including one of me hunched over my teeny-tiny note-taking laptop doing the exciting live-blogging thing. It doesn't look as glamorous as it actually is.
pharyngula | October 31, 2009This talk should put me back in my comfort zone—developmental biology, evolution, and fish, with the stickleback story, one of the really cool model systems that have emerged to study those subjects.
What is the molecular basis of evolutionary change in nature? How many genetic changes are required to produce new traits? Which genes are used? What types of mutations? Few or many changes required?
The dream experiment would be to cross a whale and a bat and figure out what their genetic differences are. That's impossible, so they searched for other organisms with a suite of differences that…
pharyngula | October 31, 2009Darwin had problems with the fossil record that he explained as a result of imperfections. Modern paleo has corrected some of that with the discovery of many intermediates. Jablonski is going to talk about the fossil record as a laboratory for testing evolutionary hypotheses. Marine bivalves are model systems with both modern forms and good fossil preservation for developing analysis techniques.
The fossil record gives access to raw rates of development, unique events, and long intervals, spatial dynamics, and morphological transitions in form.
Extinction in the fossil record is a problem.…
pharyngula | October 30, 2009A phylogeny is a statement about the evolutionary history of organisms. Cladograms give branching order only, but phylograms include branch lengths as well. They inform us about diversification of lineages, patterns and rates of trait evolution, and the ages of taxa and timing of radiations.
The tree is a model for the history of life at the macroevolutionary level. Darwin fully embraced the idea.Trees now being built with DNA sequence data, using improved phylogenetic algorithms and increased computational power. We now have many well-supported phylogenies backed up by multiple lines of…
pharyngula | October 30, 2009Lander began by saying he wasn't an evolutionist — an interestingly narrow definition of the term. He's a fan of the research, but considers himself a biomedical geneticist, as if that was something different.
Having entire genomes of many species available for quantitative analysis is going to lead to a qualitative change in the science we can do.
He gave a pocket summary of the human genome project. Mouse genome followed, then rat and dog, and now have sequence (to varying degrees of completeness) of 44 species, out of 4600 mammals. Within Homo, there's the hapmap project and the 1000…
pharyngula | October 30, 2009Earlier today, Jerry mentioned to me that he noticed my earlier blog posts on the meeting, and thought I wasn't being critical enough. So I think that means I'm supposed to let my inner beast out for this one. (Nah, actually, it's because I'm in note-taking transcription mode while listening to these talks. I have to digest them for a bit before I can do any synthesis.)
What is the biogeography of speciation? Can one species split into two while splitting into two? Allopatric speciation: no gene exchange; Parapatric: limited exchange; Sympatric: free gene exchange. Allopatric is sort of the…
pharyngula | October 30, 2009There are two parallel sessions going on here at the Chicago Darwin meetings, so I can only attend half…and I'm focusing on the biology sessions. There's a whole 'nother track of philosophy and history talks that I've been neglecting! Science Life is hitting up those, as is Skip Evans of Wisconsin Citizens for Science.
pharyngula | October 30, 2009How do we distinguish bacterial species? Cohan shows us some nice diagrams of phenotypic and molecular clusters, and they show groups separated by gaps — therefore, species. Unfortunately the species defined thereby are big and contain considerable diversity within them. Darwin defined species as divergent forms between which one finds morphological gaps. Mayr: cohesive set of organisms whose divergence is constrained by genetic exchange. Speciation requires a breakdown of that exchange.
Mallet has developed a version of Darwin's species definition that includes molecular characters. Under…
pharyngula | October 30, 2009Oops, missed the first part of this talk due to the distractions of Lunch. Walked in as he was talking about tree vs. ladder thinking (people have a hard time conceptualizing trees) and history as a chronicle — barebones description of events — or a narrative — events linked by causal explanations.
It took a century for biologists to use systematics to make testable hypotheses about evolution. Darwin himself talked at length about all kinds of evidence for evolution, but strangely neglected fossils and dinosaurs altogether. Sereno blames this on rivalry with Richard Owen, who was the big…
pharyngula | October 30, 2009How do different varieties become species? Darwin credited selection. What are the details of this process? Speciation is a booming topic in the science literature, with 25,000 titles last year. Need to define a species to begin. Uses Mayr's biological species concept, which focuses on the importance of reproductive isolating factors.
Darwin on speciation: recommends Stauffer's compilation of Darwin's notes as much more thorough and specific than the Origin. Darwin explained speciation as a consequence of selection, divergence, and extinction. Mayr thought Darwin considered geographic…
pharyngula | October 30, 2009How do we explain the diversity of species in the world? The core process is speciation, a splitting of a lineage into two divergent lines that at the end, cannot interbreed. What do we know about speciation in Darwin's finches?
They evolved from a common ancestor in 2-3 million years into 14 different species, filling different ecological niches in the Galapagos, largely free of human interference. Showed us photos of four different species with very different beaks.
Developed predictions of population density from things like available biomass, and worked out relationship of expected…
pharyngula | October 30, 2009I have wireless access in the lecture hall today, so I'm going to try liveblogging these talks. This may get choppy! What it will lack in editing will be compensated for by more timely and regular updates. I hope. At least I'll be able to dump something to the site every 40-60 minutes.
He summarizes the idea that there is a wealth of genetic diversity in populations to allow for effective selection. Lack of mutations should not limit a straightforward selection response. This raises a paradox, however: organisms have phylogenetic niche conservatism. Many species are evolutionarily…
pharyngula | October 30, 2009Whoa. This was a data-rich talk, and my ability to transcribe it was over-whelmed by all the stuff Hauser was tossing out. Unfortunately, I think the talk also suffered from excess and a lack of a good overview of the material. But it was thought-provoking anyway.
One of the themes was how people resolve moral dilemmas. He began with a real world example, the story of an overweight woman in South Africa who insisted on joining a tour exploring a cave, and got stuck in the exit tunnel, trapping 22 people behind her. Do you sacrifice one to save many? One of the trapped people was a diabetic…
pharyngula | October 30, 2009
Yes. Yes we are.
(Photo by August Berkshire; if you squint, you might notice Ron Numbers caught in the background between me and Neil Shubin, too.)
pharyngula | October 29, 2009Ron Numbers gave a brief history of creationism, reminding us that perhaps a majority of the people in the world reject Darwin, and he also emphasized a few facts in that history that many would find surprising.
There was no organized opposition to evolution until the 1920s, when it was marshalled by William Jennings Bryan, who was most concerned about the ethical implications of evolution. He made the point that the popular movie about the Scopes trial, Inherit the Wind, was historically inaccurate. One of the most memorable moments in the movie was when Darrow pinned Bryan down on the date…
pharyngula | October 29, 2009It was a fine evening here in Chicago, with all these superstars of evolutionary biology in attendance. It was also an information-dense evening — I tried to keep up on my little laptop, but I know I missed a lot. Fortunately, I'm not alone: Rob Mitchum and Jeremy Manier were also covering the event, and have a play-by-play available. I'll just dump what I've got here tonight. I do have wi-fi passwords so I can get things up a little more promptly tomorrow and Saturday.
Richard Lewontin opened up with a few deprecatory comments about the religiosity of our surroundings (the talks were given…