How the leopard got its spots...

I pass on this interesting bit from the Nov. 5 Science Magazine's 'Editor's Choice" section describing work by Allen et al. :

The evolution of color patterns in animal coats has long been of interest to evolutionary biologists. From stripes on tigers to leopard spots and even the lion's plain coat, members of the cat family (Felidae) display some of the most striking patterns and variation in the degree of patterning across species. Camouflaging may be especially important in felids due to their stalking predatory behavior; however, the degree to which this shapes patterning across the family is unresolved. Allen et al. now compare mathematical model–generated categories of pattern complexity and variation to the phylogenetic history of the family and find that coat patterning is a highly changeable trait, which is largely related to felids' ecology. For instance, spots occur in species that live in closed environments, such as forests, and particularly complex patterns are found in arboreal and nocturnal species. In contrast, most species that live in open habitats, such as savannahs and mountains, have plain coats. These findings imply that spots provide camouflage in the spotted light found in forest canopies, whereas nonpatterned animals do better in the flat light of an open habitat. Thus, strong selection for background matching has rapidly generated tremendous diversity in coat patterning among felids.