al, and some species, like the mandrills, can live in groups with up to 800 members, said co-author Jessica Lynch Alfaro, an adjunct assistant professor in the UCLA Department of Anthropology and UCLA's Institute for Society and Genetics. At the other extreme are solitary species, like the orangutans. In most orangutan populations, adult males travel and sleep alone, and females are accompanied only by their young, she said. Some primates, like chimpanzees, have "fissionfusion societies," where they break up into small sub-groups and come together occasionally in very large communities. Others, like the hamadryas baboons, have tiered societies with harems, clans, bands and troops, she said.
"Our research suggests increasing group size puts more pressure on the evolution of coloration across different sub-regions of the face," Michael Alfaro said.
This allows members of a species to have "more communication avenues, a greater repertoire of facial vocabulary, which is advantageous if you're interacting with many members of your species," he said.
The research, federally funded by the National Science Foundation and supported through a postdoctoral fellowship from the UCLA Institute for Society and Genetics, was published Nov. 11 in the journal Nature Communications.
Lead study author Sharlene Santana used photographs of primate faces for her analysis and devised a new method to quantify the complex patterns of primate faces. She divided each face into several regions; classified the color of each part of the face, including the hair and skin; and assigned a score based on the total number of different colors across the facial regions. This numerical score is called the "facial complexity" score. The life scientists then studied how the complexity scores of primate faces were related to primates' social systems.
The habitat where species live presents many potential pressures that could have influenced the ePage: 1 2 3 4 5 Related biology news :1
. IU biologists offer clearer picture of how protein machine systems tweak gene expression2
. Microbiologists can now measure extremely slow life3
. American Society of Plant Biologists honors early career women scientists4
. Penn biologists identify a key enzyme involved in protecting nerves from degeneration5
. University of Toronto biologists predict extinction for organisms with poor quality genes6
. Biologists turn back the clock to understand evolution of sex differences7
. Double the pain: RUB biologists find the cause of pain in the treatment of fair skin cancer8
. UCLA biologists reveal potential fatal flaw in iconic sexual selection study9
. New book on stereology by Mark West is essential reading for neurobiologists10
. SF State biologists tag zombees to track their flight11
. Biologists unlocking the secrets of plant defenses, 1 piece at a time