Phylogenetics

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Category archives for Phylogenetics

Family Values

I’m sure by now you’ve heard of the ginormous spider web that was spun in Texas. The thing was huge — 200 yards long — and it was spun by multiple different species. That interspecific collaboration got Bill Poser thinking, so he blogged about it at Language Log: The web covers hundreds of square meters.…

Remember when I said that the near future of eukaryotic genome sequence would involve sequencing EST libraries (collections of mRNA, or transcribed genes) rather than de novo sequencing of whole genomes? Well, I did, even if you don’t remember. Anyway, a new paper in PLoS ONE puts that approach to the test for the purpose…

Phylogeny Friday – 06 July 2007

This week’s phylogeny takes a look at the green portion of the eukaryotic tree. These are the eukaryotes capable of photosynthesis. Eukaryotes first obtained the ability to perform photosynthesis when a eukaryotic cell absorbed a photosynthetic cyanobacterium. This was followed by a few subsequent horizontal transmissions of the endosymbiont between unrelated eukaryotic lineages. Although eukaryotic…

Phylogeny Friday – 27 April 2007

This week’s phylogeny comes from this paper on molecular dating of speciation events. I won’t be addressing molecular dating per se, but I will be dealing with what molecular clocks tell us. Like, do they actually reveal the speciation time of a pair of species?

Phylogeny Friday – 13 April 2006

Today’s password is coevolution.

Phylogeny Friday – 30 March 2007

Mammals 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…

Phylogeny Friday — 16 March 2007

New Terms in Phylogenetics I’m a cladist, and as a cladist I want all of my taxa monophyletic. That means anything given a name (animals, plants, vertebrates, insects, etc.) should include all the organisms that descend from the most recent common ancestor (MRCA) shared by the organisms you claim are in that group. Confused? Well,…

The five nurses and one doctor (the Tripoli Six) accused of infecting hundreds of patients with HIV in Libya are awaiting the verdict of their trial, expected to be handed down on December 19. The second trial concluded on November 4 — the original guilty verdict was overturned. I previously mentioned that the molecular evidence…

Phylogeny Friday – 1 December 2006

What if some phylogenies were simply irresolvable? That is, what if, no matter how much data we collected, it would be impossible to reconstruct, with a high level of certainty, an accurate representation of the tree of life? That would suck. A lot. I have mentioned how this can result from long branch attraction or…

Are There Three Domains of Life?

Like a lot of evolutionary biologists not studying the root of the tree of life, I assumed the three domain hypothesis was fairly well supported by the research community. This model posits that the tree of life can be broken up into three taxa at its most basal level: eukaryotes, bacteria, and archaea. It’s the…