This study claims that colour vision in primates developed in order to detect blushing in the butts of other apes.
Some things never change... http://abcnews.go.com/US/wireStory?id=1680841 All the better to see you blush, my dear... Reuters WASHINGTON - Primates may have evolved color vision not to find the ripest, tastiest fruit but to detect that tell-tale blush on someone else's rump, U.S. researchers reported on Thursday. The cone structures in the eye that help detect color seem exquisitely tuned to skin tones, the team at the California Institute of Technology reports. "For a hundred years, we've thought that color vision was for finding the right fruit to eat when it was ripe," Mark Changizi, a theoretical neurobiologist and postdoctoral researcher at Caltech who led the study, said in a statement. "But if you look at the variety of diets of all the primates having trichromat (three-color) vision, the evidence is not overwhelming." Instead, Changizi and colleagues report in the current issue of the journal Biology Letters, the system seems adapted especially to find the colors prevalent in primate skins -- notably changes due to how much oxygenated hemoglobin is in the blood. In contrast, bees have four color cones that are evenly spread across the visible spectrum, with the high-frequency end extending into the ultraviolet. Birds have three color cones that are also evenly distributed in the visible spectrum. And the three-cone system can help a primate tell not only if a potential partner is having a rush of emotion in anticipation of mating, but also if an enemy's blood has drained out of his face due to fear. "Also, ecologically, when you're more oxygenated, you're in better shape," Changizi said. That may be why humans value rosy cheeks, he said. The clincher -- Changizi said old-world primates that have the three-cone vision are also all bare-faced and bare-butted. "There's no sense in being able to see the slight color variations in skin if you can't see the skin," Changizi said. "This could connect up with why we're the 'naked ape,"' he added. Copyright 2006 Reuters News Service. All rights reserved. -- Your representative owes you, not his industry only, but his judgment; and he betrays instead of serving you if he sacrifices it to your opinion. Edmond Burke ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~| Message: http://www.houseoffusion.com/lists.cfm/link=i:5:198702 Archives: http://www.houseoffusion.com/cf_lists/threads.cfm/5 Subscription: http://www.houseoffusion.com/lists.cfm/link=s:5 Unsubscribe: http://www.houseoffusion.com/cf_lists/unsubscribe.cfm?user=11502.10531.5 Donations & Support: http://www.houseoffusion.com/tiny.cfm/54
