Last month scientist discovered a new species of
Galapagos tortoise. These are the giants that helped inspire Darwin’s theory of
evolution. This new species of Galapagos tortoise lives in eastern Santa Cruz,
also known as Cerro Fatal or Deadly Hill, due to its arid and lava-laced
environment. This is confirmed as the 14th Galapagos tortoise. The
new species goes by the name, Chelonoisis donfaustoi, after Fausto Llerena
Sanchez who just retired after forty-three years of helping to save the
endangered tortoises.
The species evidently has more in common genetically
with species of tortoise on other islands and less in common with Santa Cruz’s
main tortoise. Although it is not common for separate species to breed with
each other, the genetic evidence shows that the two Santa Cruz species have
mated. The genetic analysis that compared Cerro Fatal DNA with DNA from all
known species showed that the Reserva specimen contained traces of Cerro Fatal
DNA, which indicated that the two species can actually interbreed but have a
tendency not to. Cerro Fatal has about two-hundred and fifty tortoises, while
La Reserva, a moister and elevated part of Santa Cruz has about two-thousand
tortoises. Reserva tortoises have been in existence for one and three-quarter
million years, unlike the Cerro Fatal tortoises which have only existed for
less than half a million years.
Although the two tortoise types shared an island,
genetic analysis revealed that the closest relatives the two species have in
common are from San Cristolbal which is the most eastern Galapagos island. This
analysis also revealed that they are not each other’s sister species and that
the Cerro Fatal tortoises evolved much more recently. Tortoise expert, Peter
Paul van Dijk stated that the “results suggest that Cerro Fatal tortoise probably
drifted to Santa Cruz during a once-in-a-decade or once-in-a-century extreme
weather event.”
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