After 150 years of thought to be extinct, a kind of giant Galapagos tortoises will come back "alive", the scientists reported on Monday (01/09/2012).
The researchers found the missing species-called elephantopus chelonoidis-by analyzing the genomes of other closely related species, Chelonoidis becki. This second type of life on the island of Isabela, the largest island in the Galapagos Islands, Pacific Ocean. The island is located about 322 kilometers from the island of Floreana, where Chelonoidis elephantopus last seen before disappearing, presumably due to hunting by whalers, about 150 years ago.
Both species of giant tortoises that live on the Galapagos Islands that has a shell that looks different. C shell on the island of Floreana elephantopus saddle-shaped, while the tortoise on other islands, including C. becki, has a dome-shaped shell. This giant turtle can reach weights almost 408 pounds and a length of almost 1.8 meters.
The discovery of mixed ancestry
In 2008 the researchers found that some C becki tortoise has a shell shaped more like a saddle than a dome. They believe that this is a mixed ancestry (hybrid) of a marriage between two different species. They then took samples for genetic analysis of the 1669 large tortoise from the island, or about 20 percent of the total population. The result, found some pieces of the genomes of C. elephantopus in the population.
Using a special computer model, they analyze when these genes into the population. Clearly, the mixing of genes that occurs when a C elephantopus mating with C. becki-and this is indirect evidence that at that time still exist tortoise type C elephantopus living.
They found, 84 of the tortoise has a genetic indicator that one of them is C elephantopus parent, and 30 of them aged less than 15 years. Given the age of turtles can reach 100 years, the researchers said the most likely parent of the opposite C elephantopus still alive.
"This is the first species of living things are found again in a way that left genetic traces in the genome of their mixed ancestry," said Ryan Garrick researchers from Yale University, and is now an assistant professor at the University of Mississippi. "These findings give a new breath of life to conservation efforts for these animals."
Based on genetic differences between the tortoise mulatto, the researchers estimate that at least 38 C elephantopus tail left half-breed in the Galapagos Islands, and some may still be alive.
Turning an extinct
If researchers can find these populations, they could capture some to be a parent in a breeding program so that the species is "alive" again. In a paper published January 9, 2012 in the journal Current Biology, the researchers write even the possibility of "raising" of pieces of genetic species found in freshwater kuran type C becki.
"If we can find these animals, we can restore them to their native island. This is important because the animals are the key species that play an important role in maintaining ecological integrity in there," said researcher Gisella Caccone from Yale University.
In an interesting discussion, the researchers are still wondering how a giant tortoise can move from the island of Floreana to Isabela. They suspect the animals may be brought to Isabela as food and then thrown overboard or left on the beach.
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