By developing methods to integrate information across several algorithms and diverse data sources, we provide a validated haplotype map of 38|[thinsp]|million single nucleotide polymorphisms, 1.4|[thinsp]|million short insertions and deletions, and more than 14,000 larger deletions. We show that individuals from different populations carry different profiles of rare and common variants, and that low-frequency variants show substantial geographic differentiation, which is further increased by the action of purifying selection.
That's really the tip of the iceberg. A study published in May 2012 found one genetic variant in every 17 genetic letters.
The scientists discovered one genetic variant every 17 bases, which was a dramatically higher rate than they expected, said Novembre, a population geneticist who is a member of UCLA's interdepartmental program in bioinformatics.
Most of the time, only one person has the genetic variant and the other 14,001 do not.
To put that in perspective, we've got 2.9 billion bases. That suggests perhaps 170 million genetic variants, most waiting to be found. This makes identifying which ones are functionally significant much harder. It also makes humans more genetically different from each other than we heard when the first human genome was sequenced back in the 1990s.
Since genome sequencing costs are still dropping we are going to see the number of genomes fully sequenced go up by orders of magnitude into the tens of millions and beyond. While the impact of rarer genetic variants will be harder to figure out we will see a huge flood of discoveries on the meaning of more common genetic variants.
We are not many years away from the point where pre-implantation genetic testing of embryos starts to make sense. Once the functional purposes of enough genetic variants become known I expect millions will choose among several embryos to get the best choice of genetic variants for their offspring. Human evolution will start to accelerate at that point.
|Share |||Randall Parker, 2012 October 31 09:54 PM|