Pharyngula

Archives for October, 2009

Because we’re all geeks and nerds.

A 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…

Lander 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…

Earlier 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…

More coverage elsewhere

There 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.

How 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…

Oops, 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…

How 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…

How 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…

I 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…