A protein called hdac4 promotes good eyesight.
Reduced levels of this protein causes the death of retinal cells
Thursday 19 February 2009
Saturday 14 February 2009
The 10,000 year explosion;How civilization accelerated himan evolution
The authors found evidence of 4,000 `selective sweeps' with the help of the human genome project,`selective sweeps' which toot place 40-80,000 years ago
African genetics
Pygmies have a single origin, so a study suggests.
The study suggests pygmies originated 90,000 or 54,000 years ago.
Until about 800BC, the pygmies were one interbreeding population, when the expansion of non-pygmy population caused genetic divergance.
Pygmies have a genetic mutation that causes them to be small in statue.
khoisan and pygmy populations appear to have same ancestry.
71% of american african ancestry appears to be Niger-Kordofanian.
Khoisan mtdna and y chromosome analysis indicates divergance about 35,000 years ago.
It is suggested that modern human migrated from a point near Angolan/namibian border.
Out of africa waypoint supposely at red sea midpoint
The study suggests pygmies originated 90,000 or 54,000 years ago.
Until about 800BC, the pygmies were one interbreeding population, when the expansion of non-pygmy population caused genetic divergance.
Pygmies have a genetic mutation that causes them to be small in statue.
khoisan and pygmy populations appear to have same ancestry.
71% of american african ancestry appears to be Niger-Kordofanian.
Khoisan mtdna and y chromosome analysis indicates divergance about 35,000 years ago.
It is suggested that modern human migrated from a point near Angolan/namibian border.
Out of africa waypoint supposely at red sea midpoint
Friday 13 February 2009
genes linked to taste
Africans may be better able to taste PTC(phenylthiocarbamide)
Whereas asians and europeans have only two versions of TAS2R38, the gene that lets us taste PTC,africans have several different variants.
Tas1R3 has been linked to the taste of sweetness,most europeans have both of the two version of the gene.
Variants of this gene are less prevalent in asian amd middle eastern people, and least prevalent in africans.
In the pamir mountains of northeastern afghanistan 37% of people are `supertasters', a bit of dark chocolate would taste bitter,only 7-15% of europeans are `supertasters'.
There are 25 T2R genes of which there can be several versions.
A variation of the T2R16 bitter taste receptor present in central africa metabolizes glycosides in the stomach releasing toxic cyanide,believed that this variation persists because it offers resistance against malaria.
Those with T2R38 cannot taste PTC
Whereas asians and europeans have only two versions of TAS2R38, the gene that lets us taste PTC,africans have several different variants.
Tas1R3 has been linked to the taste of sweetness,most europeans have both of the two version of the gene.
Variants of this gene are less prevalent in asian amd middle eastern people, and least prevalent in africans.
In the pamir mountains of northeastern afghanistan 37% of people are `supertasters', a bit of dark chocolate would taste bitter,only 7-15% of europeans are `supertasters'.
There are 25 T2R genes of which there can be several versions.
A variation of the T2R16 bitter taste receptor present in central africa metabolizes glycosides in the stomach releasing toxic cyanide,believed that this variation persists because it offers resistance against malaria.
Those with T2R38 cannot taste PTC
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