This month's Nature Genetics has a meeting report on the Human Genome Variation 2006 conference. This little bit caught my eye:

Andrew Clark and Neil Risch provided some exciting first glimpses into these large data sets, including some remarkable findings in population genetics. For instance, Andrew Clark examined global FST in different regions of the US and noted clear evidence of a gradient of allele frequencies that could partially be explained by the demographic history. He also noted some striking differences in heterozygosity and patterns of linkage disequilibrium between HapMap Caucasians and Ashkenazi subjects from an ongoing study.

Remember that natural selection can be inferred from linkage disequilibrium patterns. Andy Clark was never too keen on the selection for Ashkenazi intelligence thing; I wonder where these LD data are taking him.