Why are southerners shorter than northerners?

The height difference between southerners and northerners is caused by geographical environment.

1, German biologist Karl Bergman's "Bergman's Law" holds that for the same warm-blooded animal, the bigger its individual is in a cold place, the shorter its appendages and appendages are in a cold place.

2. Because human skin has a great heat dissipation function, people live in the tropics, and the cold zone has less heat dissipation, which will help warm-blooded animals regulate their body temperature.

The ancestors of northerners are mainly nomadic people. They travel by horse and eat beef, mutton, dairy products and coarse grains. The ancestors of southerners engaged in agricultural production, often shouldered, with developed arms and short legs. The diet is mainly vegetables and rice.

4. Secondly, northerners eat a lot, and southerners go to northern restaurants to order a dish, but one person can't finish it; It is not enough for northerners to order a dish in the South Hotel.

5. However, the height difference between north and south is not absolute.