Fig. 4
From: Bone-associated gene evolution and the origin of flight in birds
Venn diagrams of positively-selected bone-associated genes. a Intersection between positively-selected genes shared in different combinations among mammals and birds, with the datasets including only terrestrial mammals and flying birds. b Intersection between positively-selected genes in terrestrial mammals, flying birds and those genes showing a different evolutionary rate in bats. c Intersection between positively-selected genes in terrestrial mammals, branch of flightless birds and flying birds. Asterisks (*) represent genes where the foreground branch was slower than background