Humans are the only animals with this body part — and no one knows why

[applegrove]

http://www.businessinsider.com/humans-are-the-only-animals-with-this-body-part-2016-1

Ed Yong, The Atlantic and Business Insider

"SNIP.............


The thing is: Pigs don't have chins. Nor do any animals, except for us.

The lower jaw of a chimpanzee or gorilla slopes backwards from the front teeth. So did the jaw of other hominids like Homo erectus.

Even Neanderthal jaws ended in a flat vertical plane. Only in modern humans does the lower jaw end in a protruding strut of bone. A sticky-outy bit. A chin.

“It's really strange that only humans have chins,” says James Pampush from Duke University. “When we're looking at things that are uniquely human, we can't look to big brains or bipedalism because our extinct relatives had those. But they didn't have chins.


.............SNIP"

[applegrove]

1. Maybe a chin was a handle that allowed humans to rest their heads

Last edited Wed Feb 24, 2016, 01:21 AM - Edit history (2)

on their hands if they were lying down on their stomachs, or sitting, allowing for bigger heads. And thinner necks. Fewer neck muscles at the back.Surely early humans lay down in a group and rested their heads on their hands. So they could pay attention to each other. I used to lay down like that a lot as a kid. And look up. And watch and listen and talk. Maybe with fire, culture and storytelling became things that were more important and you had to be able to rest your body while still awake into the night. And you had to be looking up.

[applegrove]

3. I guess they mean something that sticks out beyond the lips and edge of the mouth.

[DhhD]

5. It could be the evolution of running while breathing through the best nasal apparatus available

with a jaw that allows for mouth breathing and throat cooling of the blood going to the brain as in a unique human thermo-regulation during long hunts and fast travel. And with canals and vesicle that make the position of the head well known and balanced during running, hunting and survival endeavors.

http://www.slate.com/articles/health_and_science/new_scientist/2013/06/daniel_lieberman_long_distance_running_we_evolved_endurance_and_dislike.html

http://www.nature.com/news/2004/041115/full/news041115-9.html

[alfredo]

6. The chin is a good anchor for lip muscles.

[Judi Lynn]

7. An outstanding DU'er pointed put years ago Republicans tend to be light on chins, themselves.

[center]



Nathan Sproul, campaign organizer









ETC.[/center]

[applegrove]

8. He he he. Funny.