Evolution of Flight and Immunity
A juvenile male Pteropus alecto (black flying fox) spreading its wings (for adults, average wing span: ~1 meter; average weight range: 500 to 1000 grams). Bats, the only mammals capable of sustained flight, are among the world's most diverse mammals and are host to numerous deadly viruses. Comparative genome analyses have shed new light on the evolution of bat-specific traits, including flight and immunity. See page 456. Photo: Martin Asser Hansen/ 
Bats are the only mammals capable of sustained flight and are notorious reservoir hosts for some of the world's most highly pathogenic viruses, including Nipah, Hendra, Ebola, and severe acute respiratory syndrome (SARS). To identify genetic changes associated with the development of bat-specific traits, we performed whole-genome sequencing and comparative analyses of two distantly related species, fruit bat Pteropus alecto and insectivorous bat Myotis davidii. We discovered an unexpected concentration of positively selected genes in the DNA damage checkpoint and nuclear factor κB pathways that may be related to the origin of flight, as well as expansion and contraction of important gene families. Comparison of bat genomes with other mammalian species has provided new insights into bat biology and evolution.  

ScienceVol. 339 no. 6118 pp. 456-460