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August 19, 2010
Posted by invictus under Anthropology
| Tags: Biology
, human genome
, mitochondrial eve
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Image via Wikipedia
The most robust statistical examination to date of our species’ genetic links to “mitochondrial Eve” the maternal ancestor of all living humans confirms that she lived about 200,000 years ago.
|The Rice University study was based on a side by side comparison of 10 human genetic models that each aim to determine when Eve lived using a very different set of assumptions about the way humans migrated, expanded and spread across Earth. (more…)
August 6, 2010
Iceman, the Neolithic mummy found accidentally in the Eastern
Alps by German hikers in 1991, has offered researchers all sorts of clues to
life 5,200 years ago, from his goat-hide coat to the meat and unleavened bread
in his stomach to the arrow wound in his shoulder.
Now, scientists stand poised to find out a whole lot more
about Iceman, who also goes by Ötzi, Frozen Fritz and Similaun Man.
They recently finished sequencing the Iceman’s genome,
which took about three months – a feat made possible by whole genome sequencing
technology. With that map of his genes in hand, researchers are moving onto to
a whole new array of questions, according to Albert Zink, head of the European
Institute for Mummies and the Iceman at the European Academy of Bozen/Bolzano
(EURAC) in Italy.
“Some are very simple, like so ‘What was really the eye color of
the Iceman? What was really his hair color?'” Zink said. There are more
complicated questions, too. Zink and others are curious about any genetic
evidence of disease in the Iceman and the composition of his immune system.
And there’s the big one, he told LiveScience: “Are
there any living relatives of the Iceman still around?”
Scientists have already taken a stab at this question when
they analyzed DNA from Iceman’s
mitochondria – energy-producing centers of cells – and compared the results
with groups of living individuals. They did not find any matches, suggesting his
maternal lineage is either very rare or died out. (Mitochondrial DNA is passed
down from mothers to their children and so would only provide relatives on
Iceman’s mom’s side of the family.)
“We have to take into account this is only the maternal
lineage,” he said, referring to the mitochondrial study. “And not all
people are tested.”
Until now, scientists hadn’t mapped the DNA within the
nuclei of his cells. For humans, nuclear DNA contains 6 billion base pairs,
while mitochondrial DNA only includes 15,000 to 17,000, according to Zink.
Read more at www.livescience.com