How Sliced Meat May Have Driven Human Evolution (sciencemag.org)

sciencehabit writes: The most tedious part of a chimpanzee's life is chewing. Our primate cousins spend six hours a day gnashing fruits and the occasional monkey carcass — all made possible by the same type of big teeth and large jaws our early ancestors had. So why are our own teeth and jaws so much smaller? A new study credits the advent of simple stone tools to slice meat and pound root vegetables, which could have dramatically reduced the time and force needed to chew, thus allowing our more immediate ancestors to evolve the physical features required for speech. The abstract for the (paywalled) article is more informative than many.

Comments

Tooth longevity

[Anonymous Coward]

Surprised they didn't mention that a longer lasting tooth would have been a huge advantage as well:

"Slicing, whether with a knife or a sharp stone flake, changes all that. Suddenly, hominins could cut up the elastic muscles of a carcass into smaller bits before putting them in their mouths, making them chewable and easier to digest. Pounding has a similar effect on tough, fibrous root vegetables. “What we found is that by simply slicing meat and pounding vegetables, a hominin would be able to reduce the number of chews they use by about 17%,” Zink says. “That equates to 2-and-a-half million fewer chews per year.”

Imagine a 17% less worn tooth. Tooth loss is a huge disadvantage in the wild, just look at how desperate large predators get when they cannot hunt effectively.

An individual living 17% longer would be able to learn and pass on their knowledge and build a more effective society, perhaps even helping invent fire along the way.

Re:Tooth longevity

[Opportunist]

Wolves and lions with bad teeth simply die.

Also, these animals are a rather poor example of why living longer than one generation needs to procreate has a benefit. They do not tend to live in multi-generation packs. We do. Even today having parents to rely on when you have offspring is a huge advantage compared to those who cannot drop their young on their own parents to go out and earn a living. Consider how much higher the chances for your pack were when you went out hunting while your young were protected by your own parents who not only provide protection but can also aid you with their experience in rearing offspring.

IIRC the life expectancy of an early human who survived the first 5 years of his life was in the area of 35 years. 17% only means about 5-7 extra years, but it can make a huge difference for the chance of your kids' survival if your parents are around an extra 5-7 years. Considering that a woman can bear children about roughly once a year, this can mean an extra 5 offspring surviving.

Re:Beef Jerky is Devolution

[srmalloy]

Putting it in the bottom of a bowl before filling it with lobscouse will render it edible by the time you're down to it. Or you can pound it back to flour, mix it with suet and some leavening, and bake it again to make duff, or bag the dough and boil it to make pudding duff.

Fire

[wisnoskij]

Knives don't really replace chewing, fire does that.

Re:Beef Jerky is Devolution

[ColdWetDog]

I always thought they were for building emergency shelters....