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[lalaloo73]

I'm taking an online nutrition class.  our current topic of the week is "are you a vegetarian?".  someone in the class posted a response with a really crappy attitude and incorrect information.  (read below)

"Humans are predators.  That is how our bodies are built, from the shape of our teeth to the placement of our eyes.  I for one completely

Comments

[shaydlip]

First, evolutionary psychology has identified several behavioral adaptations--including much of our hand-eye coordination skills--as probably being derived from and for hunting. This may be traits maintained and modified from our insectivorous ancenstry, but we have maintained them pretty well.

Our closes insectivorous ancestor would have been about 60 mya, so probably not. Also, ususally indigenous populations hunt not by spears but by tracking and "running" down animals over long periods of time. Humans have a much better ability for longevity than quadrupedal animals.

Also, many of our gender differences unrelated to sexual selection and reproduction appear to be tied to a hunting vs. "gathering" dichotomy...

I highly doubt this as well. The majority of sex differences in terms of the body are due to females needing to bear children more than anything else. It's significantly more difficult for human females to bear children than other species, except for maybe ungulates (horses)

But I agree with most else, but a new idea coming up is that humans evolved the way we did to eat underground storage organs (potatos, yams, etc), but the research is just just coming out on this so we'll have to see. However, while I think the majority of our caloric intake came from these vegetative sources, that does not mean we didn't need meat. We might have just had a lower threshold for our meat needs.

Yeah our teeth pretty much suck for meat. Have you ever tried to cut through uncooked meat?? It's REALLY tough. You want high shearing crests for that.

[caerbannogbunny]

"Our closes insectivorous ancestor would have been about 60 mya, so probably not. Also, ususally indigenous populations hunt not by spears but by tracking and "running" down animals over long periods of time. Humans have a much better ability for longevity than quadrupedal animals."

Right...

...but I'm talking about skills manifesting from neuromechanisms/design and not the more morphological and physiological differences from running. Humans have been tool users for a very long time and--assuming the insectivore descent is correct--tracking moving objects and making them connect in a three dimensional world for a very, very long time. That tends to be a more predatory skill than an herbivorous skill. Generally speaking, all a herbivore has to do is locae the plant--which stays still--and procure the parts it wants to eat. An argument for evading predators... making sure things do NOT connect in a three dimensional world could be had except those are more proactive skills than predictive.

"I highly doubt this as well. The majority of sex differences in terms of the body are due to females needing to bear children more than anything else. It's significantly more difficult for human females to bear children than other species, except for maybe ungulates (horses)"

Ummm... -->"Also, many of our gender differences unrelated to sexual selection and reproduction appear to be tied to a hunting vs. "gathering" dichotomy..."

*smirk*

[shaydlip]

What do you consider are gender differences unrelated to sexual selection and reproduction?

...but I'm talking about skills manifesting from neuromechanisms/design and not the more morphological and physiological differences from running. Humans have been tool users for a very long time and--assuming the insectivore descent is correct--tracking moving objects and making them connect in a three dimensional world for a very, very long time. That tends to be a more predatory skill than an herbivorous skill. Generally speaking, all a herbivore has to do is locae the plant--which stays still--and procure the parts it wants to eat. An argument for evading predators... making sure things do NOT connect in a three dimensional world could be had except those are more proactive skills than predictive.

What are you considering the insectivorous ancestor? Chimpanzees?

I also do not appreciate your smirk, what could you hope to gain from it? You have lj-put me down?

[caerbannogbunny]

No insulting... I smirk a lot.

As far as insectivorous ancestors, I mean those that led to the primates before climbing into the trees...

Gender differences unrelated to sexual selection and reproduction may include things like how each gender tend to remember places, differences in discrimination of color and smell, and other traits which are not part of either the common repertoire or specifically sexually oriented.

[sollersuk]

We don't need meat for the caloric intake as much as for the protein and minerals - particularly minerals: for example, it's far easier for the body to absorb iron from meat than from vegetables, and more of the iron in vegetables can be absorbed if they are eaten at the same time as meat.

And the caloric intake thing seems to be a vicious circle: people needed to consume more calories to do more work to grow more plants to provide them with the calories to do more work...

[insert_nanotech]

Yeah our teeth pretty much suck for meat. Have you ever tried to cut through uncooked meat?? It's REALLY tough. You want high shearing crests for that.

Could this imply that our omnivorousness is connected not merely to hunting, but to tool-using? Did hominids lose their sharp teeth (or fail to develop them) because they already had tools to cut the meat with? Does anyone have data on rhe dates involved?

[shaydlip]

You know, I don't remember the details of chimpanzee teeth, but I'm pretty sure they are similar to ours and ALSO suck at eating meat. They just do it anyways.

Also, humans aren't the only ones who use tools- lots of primates do. We just started to figure out how to sculpt stone tools, and I suspect this is an offshoot of humans just getting smarter, for other reasons than needing stone tools.

But that is speculation ;)