Week of January 14th

This week, Dr. Miller and I discussed an article that I read over break, "Whole-genome analyses resolve early branches in the tree of life of modern birds" (published in Science, December 2014). We could only meet for 45 minutes because Dr. Miller had to catch his plane, but I still got a pretty thorough understanding of recent evolutionary biology research.

This paper discusses the findings of a mammoth research project in which scientists performed a genome-scale phylogenetic analysis of 48 bird species. These 48 genomes were computationally aligned and evaluated to create the most reliable avian evolutionary tree yet produced. Previous research efforts only analyzed selected genes, but this project analyzed whole genomes, which is why it is so accurate.

Most bird species became extinct soon after dinosaurs underwent their large-scale extinction, and as a result, the branches of the avian evolutionary tree were extremely muddled. By choosing species that represented the broadest possible diversity of birds, and by using whole-genome data, these scientists created an accurate picture of avian "family history." The paper also reveals why avian genomes tend to be small compared to those of other vertebrates: because they have lost a lot of genes and have far fewer repeat sequences. 

Here is an example of one of the several figures in the paper:

Reading and discussing this paper gave me a good understanding of the current evolutionary biology research occurring. The researchers who led this project applied the same techniques that I've been learning this year, and I think learning about this research and the methods they used will help me when I start the project with the San Diego Zoo this semester.