Mammoth DNA decoded in part

[Brian Baldwin]

http://news.bbc.co.uk/1/hi/sci/tech/4535190.stm

Part of the article...

Scientists have pieced together part of the genetic recipe of the extinct woolly mammoth.

The 5,000 DNA letters spell out the genetic code of its mitochondria, the structures in the cell that generate energy.
The research, published in the online edition of Nature, gives an insight into the elephant family tree.
It shows that the mammoth was most closely related to the Asian rather than the African elephant.
The three groups split from a common ancestor about six million years ago, with Asian elephants and mammoths diverging about half a million years later. "We have finally resolved the phylogeny of the mammoth which has been controversial for the last 10 years," lead author Michael Hofreiter of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, told the BBC News website.

Brian

[American Patriot]

Mammoth blood protein 'resurrected' by scientists

By Paul Rincon Science reporter, BBC News

The mutation may have helped mammoths survive in the Ice Age

Scientists have discovered genetic mutations that allowed woolly mammoths to survive freezing temperatures.

Nature Genetics reports that scientists "resurrected" a mammoth blood protein to come to their finding.



This protein, known as haemoglobin, is found in red blood cells, where it binds to and carries oxygen.



The team found that mammoths possessed a genetic adaptation allowing their haemoglobin to release oxygen into the body even at low temperatures.



The ability of haemoglobin to release oxygen to the body's tissues is generally inhibited by the cold.

The resulting haemoglobin molecules are no different than 'going back in time' and taking a blood sample from a real mammoth Kevin Campbell University of Manitoba

The researchers sequenced haemoglobin genes from the DNA of three Siberian mammoths, tens of thousands of years old, which were preserved in the permafrost.



The mammoth DNA sequences were converted into RNA (a molecule similar to DNA which is central to the production of proteins) and inserted into E. coli bacteria.



The bacteria faithfully manufactured the mammoth protein.



"The resulting haemoglobin molecules are no different than 'going back in time' and taking a blood sample from a real mammoth," said co-author Kevin Campbell, from the University of Manitoba in Canada.



Scientists then tested the "revived" mammoth proteins and found three distinctive changes in the haemoglobin sequence allowed mammoth blood to deliver oxygen to cells even at very low temperatures.



This is something the haemoglobin in living elephants cannot do.



"It has been remarkable to bring a complex protein from an extinct species back to life and discover important changes not found in any living species," said co-author Alan Cooper, director of the Australian Centre for Ancient DNA at the University of Adelaide.



Without their genetic adaptation, mammoths would have lost more energy in winter, forcing them to replace that energy by eating more.



The ancestors of woolly mammoths and modern-day elephants originated in equatorial Africa.



But between 1.2 and 2.0 million years ago, members of the mammoth lineage migrated to higher latitudes.



Writing in Nature Genetics, the scientists say that this genetic specialisation may have been crucial in allowing the ancestors of mammoths to exploit new, colder environments during Pleistocene times.
Paul.Rincon-INTERNET@bbc.co.uk

[American Patriot]

Mammoths survived late in Britain

By Paul Rincon Science reporter, BBC News

Mammoths were in Britain 6,000 years longer than had been suspected

Woolly mammoths lived in Britain as recently as 14,000 years ago, according to new radiocarbon dating evidence.

Dr Adrian Lister obtained new dates for mammoth bones unearthed in the English county of Shropshire in 1986.



His study in the Geological Journal shows the great beasts remained part of Britain's wildlife for much longer than had previously been supposed.



Mammoths may finally have died out when forests encroached on the grassland habitats they favoured for grazing.



The radiocarbon results from the adult male and four juvenile mammoths from Condover, Shropshire, reveal that the great beasts were in Britain more than 6,000 years longer than had previously been thought.

It's not the climate - in the main - that affects these animals. The climate affects the vegetation and the vegetation affects them Dr Adrian Lister, Natural History Museum

Researchers had supposed that mammoths disappeared from North-West Europe between 21,000 and 19,000 years ago, during a climatic freeze known as the last glacial maximum (LGM).
Britain's mammoth populations may indeed have vanished with this big chill.



But according to the new study, they were not gone forever. Instead, they returned when conditions eased and clung on in southern England until 14,000 years ago.



"What this usually means is that (mammoths) die out locally and then re-emigrate from refugia somewhere else," Dr Lister told BBC News.



Purification method

The specimens have been radiocarbon dated before. But the Natural History Museum researcher used a relatively new method of radiocarbon dating to get very accurate ages for the Condover fossils.



"The big issue with all radiocarbon dating is contamination from different sources. You have to be sure the sample you extracted from the fossil is absolutely pure," said Dr Lister.



"There have to be methods for purifying the sample that is extracted from the bone. In the last few years, a new method of purification has been developed at Oxford University called ultra-filtration."

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"Various bone specimens that were dated before they developed this new purification method have been shown to be out by a significant amount. Not always, but often. What they do is re-run the sample using the new method and obtain a more accurate date. That's what we did here."



Other large mammals that disappeared as the last Ice Age relented include woolly rhino, bison and giant deer.



At the same time as these species were vanishing from the Earth, human populations were expanding.



Similar die-outs of so-called "megafauna" occurred around the world at similar times, prompting some scientists to ask whether climate or human hunting played the dominant role in their extinction.





Human question

No traces of human occupation were found at the Shropshire site. But it is entirely possible that humans could have been in Britain at the same time as these last mammoths.



Dr Lister said that humans might have finished off some of the last remaining pockets of mammoths in Siberia. But he did not think people were the main cause of megafaunal extinctions at the end of the last Ice Age.



During the Ice Age, grasslands were commonplace in Europe because conditions were too cold for trees.



But as the climate warmed up, forests began to spread north, squeezing out the grassland habitats favoured by the majestic beasts.



"It's driven by climate change, but it's not the climate - in the main - that affects these animals. The climate affects the vegetation and the vegetation affects them," said Dr Lister.



"These were grass-eating animals."



Mammoths first appeared in the Pliocene Epoch, about 4.8 million years ago.
One population lived on in isolation on Russia's remote Wrangel Island until about 5,000 years ago, making them the most recent surviving population known to science.



Paul.Rincon-INTERNET@bbc.co.uk