ecorona writes: This google maps mashup http://geneworld.stanford.edu/hgdp was published in Science this week. Paywall warning: http://www.sciencemag.org/content/334/6056/583.full. It shows genetic risk for multiple diseases distributed across the globe. It's easy to follow the migration path and see which diseases increase/decrease in risk along human migration paths. Click on the populations to see the relative risk of the selected disease for each population. You can pick your a disease and see which populations are more susceptible. The article is behind a paywall, but the website is free to use.