March 10th
Gene Duplication


In genetics, the dN/dS, is the ratio of the number of non-synonymous substitutions (dN) to the number of synonymous substitutions (dS), which can be used as an indicator of selective pressure acting on a protein-coding gene. In general, a dN/dS ratio greater than one implies positive darwinian selection. Of course, it gets more complicated than that. We're counting on Mischka and Jeff to bring us up to speed but if you're not familiar with this basic concept you may want to review before reading the research article.

Mira V. Han, Jeffery P. Demuth, Casey L. McGrath, Claudio Casola, and Matthew W. Hahn (2009) Adaptive evolution of young gene duplicates in mammals. Genome Res. 19: 859-867.

for a broader perspective read the review:

Jeffery P. Demuth, Matthew W. Hahn (2009) he life and death of gene families. BioEssays 31:29–39,

This review article disucesses the magnitude, rate, and distribution of changes in gene family size, as well as by
1) briefly discussing how gene families are defined operationally and computationally.
2) reviewing estimates of the rate of gene birth and death as well as the experimental evidence for adaptive expansions and contractions in the life of gene families.
3) discussing mechanisms resulting in the origin of new families and the circumstances that result in gene family death. Finally,
4) looking at the obstacles to improving our understanding of gene family evolution



who's who contributed by: Mikey and Morgan

I'm curious to see what they come up with other than Hahn whom I covered the first week.

Snacks contributed by: Sean and Andrea