Humans have migrated across the globe for more than 100,000 years, evolving in response to the changing environment. This history of adaptation is written in our genes, with different populations carrying genetic variations affecting everything from skin colour to disease risk. These maps show how genes linked to the risk of two diseases – type 2 diabetes and biliary liver cirrhosis (a type of autoimmune disease) – vary across the world. People with gene variations putting them at the greatest risk are marked by red spots, those with a middling risk are yellow and the lowest risk are green. It shows that the risk of type 2 diabetes has gone down as people migrated out of Africa into Asia and America, while their risk of this form of liver cirrhosis has gone up. Tracking these global patterns helps researchers understand how our genes interact with our environment and lifestyle to cause disease.
Written by Kat Arney
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.