Monthly Archives: September 2011

How do we do it? Volume!

Posted on September 29, 2011 by gcochran9

In current MRI studies, the correlation of brain volume and IQ is about 0.4 – and a good thing, too.  If there was no significant correlation, we would have to conclude that natural selection didn’t work.   Here’s why. Brain tissue … Continue reading →

Posted in Uncategorized | 29 Comments

How Sweeps Get Soft

Posted on September 29, 2011 by harpend

A puzzling finding from the search for selection in humans is the large number of apparently selected variants versus the apparent absence of high frequency selected regions and regions that have become fixed in our species. If there is indeed … Continue reading →

Posted in Uncategorized | 2 Comments

Move Along, Nothing to See Here, No Selection After All

Posted on September 27, 2011 by harpend

In August of 2010 Ann Gibbons wrote a perceptive column in Science about the literature finding evidence for positive selection in the human genome. She described the burst of papers in the late 2000s on the topic and how they … Continue reading →

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All One Species

Posted on September 26, 2011 by gcochran9

We now know that anatomically modern humans with interfertile with Neanderthals and Denisovans. It seems likely that AMH was interfertile with a very divergent African group whose genes show up today in Bushmen and Pygmies. Almost certainly, Neanderthals and Denisovans … Continue reading →

Posted in Uncategorized | 4 Comments

Tea Leaves

Posted on September 25, 2011 by gcochran9

The new paper in Science about an Australian genome (An Aboriginal Australian Genome Reveals Separate Human Dispersals into Asia) hints at something new.  Comments in the supplement (and by Ann Gibbon) suggest that the Denisovans may stem from Homo erectus, … Continue reading →

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Archaic admixture – what is it good for ?

Posted on September 10, 2011 by gcochran9

It now looks as if everyone outside of sub-Saharan African has two or three percent Neanderthal ancestry. Australoids have, in addition,  somewhat more Denisovan admixture, while Pygmies and Bushmen  have a couple percent admixture from an unknown, very divergent African … Continue reading →

Posted in Archaic humans, Denisovans, Mangani, Neanderthals, Uncategorized | 2 Comments

The Jermyn Program (Part II)

Posted on September 6, 2011 by gcochran9

The general idea of the Jermyn Program is that existing races recapitulate the hominid subspecies circa 100 thousand years ago.  Back then, we had anatomically modern humans (AMH) in some fraction of subSaharan Africa and the Levant,  another unknown but … Continue reading →

Posted in Archaic humans, Denisovans, Mangani, Neanderthals | 1 Comment

The Jermyn Program (Part I)

Posted on September 5, 2011 by gcochran9

( originally in Gene Expression) The Jermyn Program Posted by gcochran on May 11, 2010 With the detection of Neanderthal admixture in Eurasians (Green et al), evidence for two admixture events in an upcoming paper from Jeffrey Long’s group (probably … Continue reading →

Posted in Archaic humans, Denisovans, Mangani, Neanderthals | 1 Comment

Stupid Penguins

Posted on September 2, 2011 by gcochran9

I said this about Bush a few years ago: If the President had decided (because of a stroke with truly interesting side effects) that we could no longer stand idly by in the eternal conflict between penguins and skuas ( … Continue reading →

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Eebers and robbers

Posted on September 2, 2011 by harpend

A year or so ago I was on a review committee for a department of biology. It was a pleasant and productive department, but it soon became apparent to us that it was in effect two departments sharing the same … Continue reading →

Posted in Uncategorized | Tagged , | 3 Comments