Mixed Blood

[Sully]

Here is an interesting question. What if you are half Eskimo, and half of a tribe from south America? Their diets differ allot. It would be interesting figuring out what works for you. 50 plants 50 Raf etc.

[boxcarguy07]

Isn't this the premise of metabolic typing?

[Sully]

I don't know what that means.

[Kristelle]

I personally believe that no matter your ancestry, ALL humans are best served by a diet composed mostly (if not exclusively) of meat and animal fat.

 

[Sully]

I personally believe that no matter your ancestry, ALL humans are best served by a diet composed mostly (if not exclusively) of meat and animal fat.

 

If there is enough time for physical changes on the outside. There is enough time for internal changes too. Correct? Enough time for humans to get diverse on the outside, but not on the inside? That doesn't make sense.

[Sully]

I personally eat mostly meat and fat. That may not be the best thing for everyone.  I could be wrong though. If something works well for you, it doesn't mean it will work well for others.

[Kristelle]

Outside changes have been minor and other than some races having adapted to lactose, there haven't been enough for some race to be well-adapted to eating a diet other than that composed mostly of meat. We can all eat veggies, fruits and even grain and survive but long-term, complications will always arise. We are omnivores because it was important to be able to subsist on other foods in those moments where meat was less abundant. But, given the choice, meat was preferred.

My 2 cents, of course...

[Squall]

This is something that I have wondered about, too. I do think that some changes are possible, however slight. I don't believe that any large changes have had a chance to occur, though.

If there is enough time for physical changes on the outside. There is enough time for internal changes too. Correct? Enough time for humans to get diverse on the outside, but not on the inside? That doesn't make sense.

I understand the temptation of equating these two types of changes: digestive and appearance. One change involves elements of the metabolic system: stomach, intestines, etc. The other involves skin. We are talking about organs, but we can't necessarily say that if one organ can change over short periods of time, then other (all) organs can do the same. This might be the case, and it might not, but making an external change and an internal change interchangeable (pun intended) because they sound the same is a logical fallacy. IMO, much more research needs to be done in this arena. If people are susceptible to different genetic tolerances of food, then that's something we would all be better off knowing about.

There are, however, some decent arguments regarding short-term digestive changes. Like Kristelle pointed out, some people can digest lactose. She also alluded to chronic disease being the result of these kinds of dietary changes. One argument along these lines is that early in the Neolithic period, the massive dietary shift away from carnivorism and toward grain eating might have resulted in a large number of deaths of people who absolutely could not handle the new foods. As long as they died before reaching the age of reproduction (ie. problematic birth, childhood issues, etc.) then they would not have had a chance to pass this massive food intolerance on to future generations. Those that did survive to reach reproductive age would have been our ancestors, and thus, most people tend to have some measurable tolerance to "unnatural" foods, at least for awhile. I guess you could call this Artificial Selection. Note, however, that chronic diseases that can kill you at the age of thirty (due to sub-par nutrition) would not have been bred out, and would have been passed down as most people tend to reproduce when they're young (and apparently) healthy. Tolerance might have been passed down but complete adaptation would probably take far longer to achieve.

And as far as skin goes: remember that its the organ that takes the most beating on a consistent basis. Unlike the digestive system which could depend on the same foods for millions of years long ago, the skin was always and is always exposed to vastly different environments. It seems logical that if anything were going to change in the short term, it would be the skin, eyes, hair, etc.

[Raw Kyle]

If there is enough time for physical changes on the outside. There is enough time for internal changes too. Correct? Enough time for humans to get diverse on the outside, but not on the inside? That doesn't make sense.

You can easily measure it by looking at people's digestive enzyme expression but I've never heard of research on this topic. I agree with Kristelle in that outside changes are much less significant and can happen much more quickly.

I read in basic biology about an insect in London that changed from almost entirely light colored to almost entirely dark colored in less than 100 years because of the pollution from the industrial revolution coating trees. A complete digestive change could never take place in this amount of time because unlike looks on the outside, if something goes wrong inside you're not just deformed, you're dead. If your enzymes to digest your main food supply don't translate from your genes you are dead on arrival in this world, and if you for some reason have a mutation allowing you to digest a different food you would have to eat it (for seemingly no reason) to find out, and also the food would have to have no toxins in it and be available etc etc.

[Sully]

Take a look at the pygmies. They have a natural characteristic of a protruding belly.(not undernourished) Similar to the chimps, I remember reading that the chimps belly protrude because they need a larger stomach for digesting all of the fibrous vegetation they eat.

Perhaps we are similar to cats, you see all these different kinds of cats... lions, tigers, cheetahs, snow leopard. Different on the outside. But their diet differs only slightly. Their diet all has one thing in common, animal flesh.

Another interesting thing. Would humans have ever eaten big prey if they never developed tools to kill them? But the same is with the chimp's tiny stick and the termites. No stick, no termits. Perhaps tools have helped drive our evolution.

[Sully]

It seems logical that if anything were going to change in the short term, it would be the skin, eyes, hair, etc.

I agree.

[Raw Kyle]

Take a look at the pygmies. They have a natural characteristic of a protruding belly.(not undernourished) Similar to the chimps, I remember reading that the chimps belly protrude because they need a larger stomach for digesting all of the fibrous vegetation they eat.

Perhaps we are similar to cats, you see all these different kinds of cats... lions, tigers, cheetahs, snow leopard. Different on the outside. But their diet differs only slightly. Their diet all has one thing in common, animal flesh.

Another interesting thing. Would humans have ever eaten big prey if they never developed tools to kill them? But the same is with the chimp's tiny stick and the termites. No stick, no termits. Perhaps tools have helped drive our evolution.

The thing about evolution is that it needs a reason to happen. If your civilization is reproducing on your diet then there is no reason for evolution to take place in that area. If you took eskimos and dropped them in another part of the world where they would have to eat something different, and they were still able to reproduce generation after generation, they would not "adapt" to another diet just because they're eating it. Just because you can eat something or have done so for thousands of years (grain for example) doesn't mean you are well adapted to it.

In order for serious genetic change to happen there has to be the consequence of dying before being able to produce healthy offspring. Any mutations that don't substantially help individuals accomplish this will not become wide spread in the population.

In other words modern people can continue to eat their grain based diet or whatever they're eating for as long as they want but unless life becomes much harder and the diet stays the same (causing some to not survive if they have stronger adverse reactions to the diet) then we will never progress towards adapting to it.

The fact that there are so few allergies to meat (never heard of them myself) and that everyone that tries it tends to do well on raw paleo leads me to believe that dietary adaptations in the various human races have diverged us a very minimal distance from each other. The most notable adaptation is increased lactase production in milk eating populations, but I haven't seen data on this and it might not even be significant.