Why we can see better than Lemuridae
What miracle of evolution gave humans the ability
to see details just inches away? Snakes, says an anthropologist who has spent
years trying to answer that question.
What miracle of evolution gave humans the ability to see details just inches away?
Snakes, says an anthropologist who has spent years trying to answer that question.
Especially venomous snakes that forced our distant relatives to improve their vision or perish.
Isbell’s theory, published in a recent issue of the Journal of Human Evolution, flies in the face of conventional wisdom and will require much more research to be verified. The current thinking holds that primates developed near-vision capabilities to help them capture bugs, or at least reach out and grab a piece of fruit.
But Isbell points out that when snakes began to eat primates, it made sense for the monkeys and apes of Africa to develop better eyesight. A snake, after all, is pretty harmless unless it’s close by. It’s not likely to romp across the lawn to attack a human, or even a smaller mammal.
But if it’s close, you better be able to see it.
Isbell says primates in Africa, who have had to fuss with snakes the longest, have the best eyesight. And South American primates, which fall between those two extremes of exposure to predation, fall between them in terms of vision.
And lemurs in Madagascar have never suffered predation by venomous snakes. They have the worst vision of primates.
Isbell says, “Primates have the best vision of all mammals,” she says. “And we have the best vision of all primates.”
Because of snakes, you can read this.
Posted: Thu - August 31, 2006 at 12:19 PM