Meat-eating helped people take over the world: Study

Giving up our vegetarian ways and choosing to include meat into our diet is what helped humankind successfully populate the planet, according to a new study.

When early humans started eating meat and hunting, the higher quality diet meant women would wean their children earlier and give birth to more children and quicker, say researchers at Lund University in Sweden.

What's more, hunting required people to step up their communication skills, plan and use tools. These new developments required bigger brains, which our robust new diets helped us develop, according to the study, which compared 70 mammalian species and found clear patterns.

"This has been known for a long time. However, no one has previously shown the strong connection between meat-eating and the duration of breastfeeding, which is a crucial piece of the puzzle in this context. Eating meat enabled the breastfeeding periods and thereby the time between births, to be shortened. This must have had a crucial impact on human evolution," says Elia Psouni of Lund University in a press release.

The researchers reject another dominant theory - that breastfeeding duration is a social thing, and that new moms cut it short because of time constraints and family size.

The team created a mathematical model using data on brain size and diet of 70 mammals and found all species stop breastfeeding when their brains have reached a particular stage of development, which carnivores reach more quickly.

"That humans seem to be so similar to other animals can of course be taken as provocative. We like to think that culture makes us different as a species. But when it comes to breastfeeding and weaning, no social or cultural explanations are needed; for our species as a whole it is a question of simple biology. Social and cultural factors surely influence the variation between humans," Psouni said.