Evolution: Do Island Lizards Prove Evolutionary Paths are Inevitable?
(Photo : REUTERS/RC)
If you could rewind time to an earlier point in evolutionary history, there's no telling what you'd get in a second go-round.
At least that's what biologists who believe evolutionary change is erratic and unrepeatable have long held.
But a new study of Caribbean lizards indicates the natural process may utterly predictable -- at least in certain circumstances, Live Science reports.
Lizards have evolved to fill similar niches in remarkably similar ways -- even on islands separated for eons by vast gulfs of water.
Anoles lizards in Jamaica, Peurto Rico, Hispaniola and Cuba look so similar you'd swear they were the same species, but they're actualy unrelated.
It's evidence that evolution has repeated itself four different times, NBC News reports. Different species independently evolved longer legs, stickier toes or thinner tails to conquer every habitat available on each island.
Some lizards developed mottled brown hides to blend in with tree bark, while others that hang out on twigs became more slender.
"What's great about these islands is that they're a natural experiment," ecologist and study leader Jonathan Losos told NBC News. "You're not restarting the clock, but you're starting it four times."
Losos added: "If you drop a lizard on one of these islands millions of years ago, you would get a very similar outcome every time you did it."
That experiment would take some time to run. National geographic points out these lizards have been separated for more than 40 million years.