January 6, 2009

Rare Pink Iguana Missed By Darwin Offers Evolution Clues

A rare kind of pink iguana, unidentified by Charles Darwin in his now historic trips to the Galapagos Islands, could give evidence of species deviation earlier than Darwin's well-known finches, researchers announced Monday.

Rosada was failed to be spotted by Darwin in his 1835 investigations, but seems to have the earliest identified discrepancy in land animals in the archipelago.

This discovery also for the first time identifies the reptiles as a new species, announced Gabriele Gentile of the University Tor Vergata in Rome, who headed the investigation.

This also linked the comprehension of the evolution of species on the islands, which are pretty much the same as they were millions of years ago and spurred Darwin's theory of evolution.

Writing in Proceedings of the National Academy of Sciences (PNAS), the researchers indicate that rosada species separated from other iguanas 5.7 million years ago.

"Despite the attention given to them, the Galapagos have not yet finished offering evolutionary novelties," Gentile told BBC News. "So far, this species is the only evidence of ancient diversification along the Galapagos land iguana lineage and documents one of the oldest events of divergence ever recorded in the Galapagos.

Darwin's visits to the Galapagos Islands gave vital evidence, creating the foundation of the theory of evolution by natural selection, which he published in the 1859 book On the Origin of Species.

Animals like the finch and tortoise exhibited slight changes of shape from island to island, causing his theory that they evolved on diverse paths in dissimilar environments.

Darwin did not stopover in the area populated by the pink iguana and so did not see the species, whose continuation implies diversification in the Galapagos occurred five million years ago. This is earlier than accredited to other Galapagos animals like the finches, Gentile noted.

"We were not the first to see this form but we were the first to say what it is and that it is a new species," Gentile said.

The creatures appear to live only by a 350,000 year old volcano, which indicates that the reptiles had to increase their size and probably lived other places in the Galapagos, Gentile said.

Dr Gentile's team thinks the rosada's minute population is so small their survival is in jeopardy.

"Our studies would indicate that the population size is very small," he said. "We only collected 36 in two years; and last year a large research team hiked up Wolf and only found 10, and most of those were ones that we'd marked earlier."


Image Caption: The rosada is now only found in one location, on the slopes of Volcano Wolf.


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