Rana Saad from the Privman lab came first place in Hive usage in 2015! She used 698,830 CPU hours, out of a total of 1,135,463 CPU hours used on the cluster in 2015.All this computer power went into estimation of a huge number of parameters in sophisticated probabilistic models of sequence evolution. The result: detection of episodes of adaptive evolution in the superfamily of genes coding for olfactory receptors in ants. That is, the genes responsible of the sense of smell in ants, which allow them to react to a wide range of odors. These odors include the many pheromones used for communication in ant societies.
Rana analyzed a huge set of 2793 genes from nine different species and tested each and every branch in this huge phylogeny (gene tree) for evidence of positive selection, i.e. natural selection pressures that led to changes in the sequence of the genes, indicating adaptive evolution of new olfactory functions. In total, Rana tested 3326 branches, out of which 293 showed significant evidence for positive selection. These genes are promising candidate genes that may be involved in the evolution of social communication in ants.
