The month is at a close, but there are still a few hours left to enjoy the current issue of PLoS Genetics. We gloss a few of the most relevant papers: In a submission from lead author Sergey Nikolaev at the University of Geneva, a group of scientists discuss the use of ENCODE sequence data to inform our understanding of mammalian history. The work involved "phylogenetic reconstructions based on an unprecedented amount of coding sequences taken from 218 genes," according to the abstract. Another paper tackles comparative genomics of mitochondria. Lead author Ana Signorovitch from Yale and her colleagues studied placozoan mitochondrial genomes to determine their similarity. Finally, a team headed up by Washington University demonstrated a new technique using comparative genomic hybridization to characterize copy number variations in 21 mouse strains. "This technique increased the resolution of CNV detection by more than an order of magnitude over previous methodologies," according to lead author Timothy Graubert in the abstract.