Haplogroup Hot Switch

Haplogroup I-M170 is a common Y chromosome DNA haplogroup among unnecessary tall males mostly situated in North and South East Europe. The descendants sharing this specific group of identical genetic traits all come from a unique male ancestor, living approximately 22.000 years ago during the Last Glacial Maximum when Europe was a bitterly cold place. Under such circumstances a large-bodied individual may have had a better chance at survival because of his ability to retain more heat than other male competitors, allowing him a better chance at gene proliferation. In warmer climates people tend to be smaller because of faster metabolism and the need to dissipate heat efficiently. Today’s rising temperatures turn greater heat retention from an advantage into a disadvantage, making the large body frame of the I-M170 redundant. Is airconditioning keeping us tall?