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 that lived approximately 22.000 years ago during the Last Glacial Maximum. Europe at that time was a bitterly cold place with average temperatures dipping 7 degrees Celcius below those in 2019. Under such circumstances a large-bodied individual probably has a better chance at survival since they’re able to retain their heat better than smaller males. This taller and larger people would have a better chance to foster offspring. In warmer climates people tend to be smaller because of the need to dissipate heat efficiently. Today’s rising temperatures have turned greater mass from an advantage into a disadvantage, making the large body frame of the I-M170 redundant. Is airconditioning keeping us tall?