How raw meat — and our ancestors’ inability to chew it — changed the course of human evolution
A new study suggests that neither we nor our ancestors were capable of eating raw meat without some form of processing. (Randy Leffingwell / Los Angeles Times)
Paleoanthropologist Daniel Lieberman chewed raw goat meat for the sake of science, so he knows from experience that it’s a challenge.
“It’s a little salty, and it’s very tough,” the Harvard University professor said. “You put it in your mouth and you chew and you chew and you chew and you chew, and nothing happens.”
As Lieberman discovered first hand, modern human teeth are not suited to breaking chunks of raw meat into pieces that are small enough to swallow.
Effective raw-meat eaters like wolves and lions have teeth that are designed for slicing through elastic muscle, almost like a pair of scissors. Humans, on the other hand, have teeth that act like a mortar and pestle. Our pearly whites are designed for crushing, not slicing. When we chew on raw meat, the meat does not break apart.
“It stays like a wad in your mouth,” Lieberman said. “It’s almost like a piece of chewing gum.”
Still, the fossil record suggests that ancient human ancestors with teeth very similar to our own were regularly consuming meat 2.5 million years ago. That meat was presumably raw because they were eating it roughly 2 million years before cooking food was a common occurrence.
Yet oddly, these meat-eating hominims had smaller teeth compared to their mostly vegetarian predecessors, as well as reduced chewing muscles and a weakened bite force, anthropologists say.