http://cnews.canoe.ca/CNEWS/Science/.../15151061.html
Scientists observing a small group of Australian lizards very closely, believe they may be watching evolution happen right before their eyes.
A variety of Australian skink - like snake but with four tiny legs - is slowly starting abandon egg laying and beginning to give birth to live offspring like a mammal does.
Skinks in the mountainous region of New South Wales have almost entirely moved to live birth. But the same species living in the lowlands along the coast are far more likely to lay eggs containing their young.
According to a 1999 study that looked at the transition that some lizards are known to make from egg-laying to live-birth, the evolutionary step only travels in one direction. Once a species begins giving live births, it never goes back to egg-laying.
Researchers speculate this could be because it's easier to keep offspring protected from the elements and predators if they are inside the mother's body, even if that means a more taxing draw of nutrients and energy from the mother.
Scientists observing a small group of Australian lizards very closely, believe they may be watching evolution happen right before their eyes.
A variety of Australian skink - like snake but with four tiny legs - is slowly starting abandon egg laying and beginning to give birth to live offspring like a mammal does.
Skinks in the mountainous region of New South Wales have almost entirely moved to live birth. But the same species living in the lowlands along the coast are far more likely to lay eggs containing their young.
According to a 1999 study that looked at the transition that some lizards are known to make from egg-laying to live-birth, the evolutionary step only travels in one direction. Once a species begins giving live births, it never goes back to egg-laying.
Researchers speculate this could be because it's easier to keep offspring protected from the elements and predators if they are inside the mother's body, even if that means a more taxing draw of nutrients and energy from the mother.
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