Well, people don't eat enough Vitamin K2. Vitamin K2 (MK-4) comes from the following sources:
Butter, Eggs, Marrow, Brains ...
K2 (MK-7) comes from these things: Natto, Aged Cheese, etc
The human body can convert K1 (Spinach, Kale etc) to K2, but not very efficiently.
Among many other things, the human body uses K2 to build enamel on teeth, strong jaws etc. It's also responsible from keeping bone healthy.
Hope that made you curious. PM me for a good link on K2
ok, of the four, three would probably be in early man's diet.
The human body can convert K1 (Spinach, Kale etc) to K2, but not very efficiently.
so, early man, who had stronger, more enameled teeth, might be more likely to have been a milenia-generational brain, egg and bone-cracking marrow eater, consuming a lot of K2 sources, before become more of a veggie/nut eater? Is that possible?