`Blind snakes moved to Madagascar from India 100mn yrs ago`

Last Updated: Wednesday, March 31, 2010 - 18:21

Washington: Blind snakes, the small
worm-like creatures found on southern continents and tropical
islands, have an Indian link, as a new study claims the
organisms hitched a ride aboard the giant slabs of Earth when
Madagascar broke off from India about 100 million years ago.

The blurry-eyed wrigglers, which feel their way through
underground homes by sensing chemicals through their skin,
comprise about 260 different species and form the largest
group of the world`s worm-like snakes -- scolecophidians.

Most organisms living on the southern continents that
were once Gondwana didn`t appear until after the continent
split apart, according to the new genetic research, appeared
in the journal Biology Letters.

"We`ve identified living organisms (the blind snakes)
that trace back to an ancient continent that split apart and
then carried these snakes with them," Blair Hedges, lead
researcher at Penn State University, told LiveScience.

According to the scientists, some 150 years ago, Gondwana
divided into East Gondwana (the landmasses of Antarctica,
India, Madagascar, and Australia) and West Gondwana (the
landmasses of South America and Africa).

Later, East Gondwana further divided into a new
paleolandmass -- called by the researchers "Indigascar" (India
plus Madagascar) -- and another comprised of Australia and
Antarctica.

"That mini-continent (India) moved northward after it
split from Madagascar, carrying blind snakes with it and
eventually colliding with Asia (causing the Himalayas),
roughly 50 million years ago," Hedges said.

"Then some of resident blind snakes left and dispersed
over land to other areas in southern Asia."

The creatures in other parts of the world must have
rafted across oceans aboard floating flotsam at least once
during their evolutionary history, the scientists said.
The small burrowing animals spend most of their lives in
the soil underground, eating the eggs and larvae of ants and
termites.

"These blind snakes eat very small things, and they eat a
lot of them," Hedges said. "They`ll go into a termite mound
and just gobble up dozens and dozens of eggs and larvae."

In fact, they have specialised jaws that work like a
conveyor belt, pulling in larvae and eggs into their mouths as
if at a checkout counter, he said.
However, scientists are perplexed over the underground
lifestyle of the creatures as they found nothing barring some
mysterious underground passages. There are almost no fossils
of blind snakes known so far that makes it difficult to
understand their evolution.

To find out how the blind snakes managed to spread from
continent to continent, Hedges and his colleagues analysed 96
blind snake species for five genes, particularly looking at
mutations in those genes.

By counting up the mutations, which is not a simple
process and so involved special computer software, the team
could figure out how long ago the species lived.

The results were then calibrated with fossils and
geological evidence to firm up the timing. The team found that
splits between species were as old as 150 million years ago,
when Gondwana was first breaking apart.
The blind snake species in Madagascar and India were
traced back to about 100 million years ago, when Indigascar
was breaking up.

PTI



First Published: Wednesday, March 31, 2010 - 18:21

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