Yesterday I saw a lizard that could move each eye independantly. I want to know why we have not evolved that way yet.
2007-04-27 16:13:16 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Zoology
With two synchronized eyes, that is binocular vision, humans are able to see in three dimensions and possess interposition of objects. As a predatorial species we need that to survive, let alone drive a car. Where as lizards need only to see motion to attack their prey.
2007-04-27 16:22:13 · answer #1 · answered by Anonymous · 1⤊ 0⤋
As mentioned both eyes focused on the same object gives depth perception. Predators need this to judge the distance of prey. However, our comes from a prior time when our ancestors were arboreal (tree dwelling). Arboreal species that are extremely active need this more than even predators. The chameleon you saw had depth perception. However, he first had to take the time to focus both eyes on the same object to get it. This takes a moment. Our binocular vision is much faster.
Most animals use the peripheral (side) vision out of each eye to look for food or danger and then instantly focus on what they want to see. This is a faster more efficent way for an animal that moves fast. If you poke along like the chameleon however you can take you time.
BTW Chameleons also do not worry much about spotting predators because they can not outrun them anyway. Instead they are colored the same as the tree or leaves (many species actually change color) and mimic a branch or leaf blowing in the wind.
2007-04-27 23:37:30 · answer #2 · answered by Jeff Sadler 7 · 0⤊ 0⤋
It is beneficial to the lizard in his environment, or past environments. An expensive " gadget " to have; independently moving eyes. We have possible a predatory past. ( one of the early primate evolutionary scenarios ) Predators have forward facing eyes. Many primates are insectivores. Perhaps, some like that were our ancestors.
PS sideways facing eyes are " prey " eyes.
2007-04-27 23:21:49 · answer #3 · answered by Anonymous · 0⤊ 0⤋
You need both eyes for depth perception. If your eyes moved in oppisate directions, it'd be harder to gauge distance.
2007-04-27 23:22:44 · answer #4 · answered by Apple 2 · 0⤊ 0⤋
That gives binocular vision which is good for estimating how far away food and threats are.
2007-04-27 23:46:32 · answer #5 · answered by Rich Z 7 · 0⤊ 0⤋
I'm not sure but some people can move their eyes different derections
2007-04-28 01:01:11 · answer #6 · answered by Anonymous · 0⤊ 0⤋