The Oxford specimen
still has soft tissue
Image courtesy Alan Cooper and Beth Shapiro
Dead it may be, but the dodo's DNA still has a story to
tell.
Researchers at the University of Oxford, UK, have taken
samples from a preserved specimen in an attempt to uncover
the extinct bird's family tree.
The DNA... is very damaged and broken
down into tiny pieces but little fragments remain
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Dr Alan Cooper
University of Oxford
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The Oxford team worked with the Natural History Museum to
collect and analyse genetic material from a preserved dodo,
from the similarly extinct solitaire bird, and from another
35 kinds of living pigeon and dove.
Their analysis shows the dodo and the solitaire to be close
relatives, with their nearest living relative the Nicobar
pigeon Caloenas nicobarica from the Nicobar Islands
and nearby south-east Asia.
Almost as closely related are the crowned pigeons of New
Guinea.
Scattered remains
The dodo was a flightless bird, bigger than a turkey, living
on Mauritius in the Indian Ocean. By 1681, it was extinct.
The solitaire, which looked a bit like a white dodo, went
the same way by the end of the following century.
All that remains of the dodo is a head and foot
at Oxford, a foot in the British Museum in London, a head
in Copenhagen, and a variety of bones strewn across museums
in Europe, the US and Mauritius.
The fragments at Oxford are unique in that they have some
soft tissue left, but in the end the researchers looked
inside a claw bone to extract short pieces of the bird's
DNA.
"The DNA survives," Alan Cooper, of the University of Oxford,
told the BBC. "It's very damaged and broken down into tiny
pieces, but little fragments remain in the cells preserved
in the old specimens."
Isolated development
By comparing these pieces with the DNA of living birds,
the scientists were able to deduce when the dodo evolved
away from its relatives into a separate entity.
They think that it separated from the solitaire about 25
million years ago, long before Mauritius became an island.
The dodo went on to develop its distinctive appearance
and features as a result of its geographical isolation,
they believe.
The dodo's odd shape has been the reason for the historical
confusion about its origins.
"It's very important that we get DNA from these birds because
they've changed so dramatically on the islands that it's
very difficult to work out what their evolutionary history
is," said Dr Cooper.
"The dodo and solitaire have been linked variously with
birds of prey, parrots, pigeons of course and even the ostrich
and emu," he added.
Details of the research appear in the journal Science.
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