Colder Climates Meant Bigger Bodies For Ancient Humans

https://www.npr.org/2021/07/08/ [login to see] /colder-climates-meant-bigger-bodies-for-ancient-humans
Big bodies are good for cold places.

That's the gist of a foundational rule in ecology that has been around since the mid-1800s: Animals that live in colder places tend to have larger bodies, especially birds and mammals that need to regulate their body temperatures. For example, some of the largest whale and bear species have evolved in the coldest reaches of the planet.

The rule applies broadly to modern humans too. Populations that evolved in colder places generally have bigger bodies.

That's also true of human ancestors, a new study finds. The research offers conclusive evidence that human body size and climate are historically connected.

In general, our ancient relatives got much larger as they evolved. "Over the last million years, you see that body size changes by about 50% and brain size actually triples, which is a lot," explains Andrea Manica, an evolutionary ecologist at the University of Cambridge. "And there have been all sorts of theories about what might have underpinned those two big changes in size."