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Thread: Punctuated Equilibrium? page 3

  1. #21
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    By the way, I know it's really hard to communicate properly via the internet. I'm not the least bit ticked-off, I'm enjoying this debate very much! I love brain-storming.


  2. #22
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    well in the interest of brain-storming. I doubt chimps eat grains, they certainly are not cultivating them. So even if they did eat them, collecting a few grass seed in the fall would not amount to a significant percentage of their diet over all. Even if they gorged on them when they were available.


    The thing with grass seeds are that they are pretty darn tough, they have been naturally selected to discourage eating and when they are to pass through animals digestive tract and grow where they were deposited (apparently some farmers use this method to plant new pasture land). These plants stood the test of time because the animals couldn't eat them. I think it is therefore logical to assume that we started out intolerant of grains. But with our big brains we learned how to defeat those defenses of the seed by soaking and fermenting and grinding and nixtamalization to make them edible.


    I also believe that our artificial selection of these grains has led to a situation where these defense mechanism have been increased. We have selected the grains that are the most disease resistant, meaning they have the best defenses. These defenses by design are damaging to our gut, the faster the seed pass, the more likely they are to grow. IBS and all these other, sort of sub-clinical ailments that are rampant in our society today, and probably have been for years, we just didn't have a name or TV commercials for them in the past.


    you might find this discussion interesting

    http://www.paleonu.com/panu-weblog/2...al-grains.html

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  3. #23
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    Getting a bit off-topic, but what the heck.....


    Since humans and chimpanzees have very similar DNA (more than 99%) I figured I may as well find out what chimpanzees eat. Here's the info from the Honolulu Zoo:


    Chimpanzee diets are composed mainly of ripe fruits but vary according to the time of the year and abundance of specific food items. They will spend many hours a day eating about 20 different species of plants and up to about 300 different species during a one year period. They do not store food and will eat it at the place they find it. They also enjoy eating young leaves particularly in the afternoon. In long dry seasons when fruit is scarce, tree seeds, flowers, soft pith, galls, resin and bark become an important part of their diet.


  4. #24
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    I also don't think that other modern primates would be applicable for comparison as we are not descended from them. Instead, we share a common ancestor and are more like "cousins;" therefore, differences in diet and digestive capabilities could be attributed to divergent evolution. Plus, I don't think any primates today eat grains.


    I am still intrigued by the ancient practices of soaking and fermenting certain grains in order to consume them. In a sense, haven't we also changed many other wild plants through domestication? For example, the broccoli we all love so much didn't exist in the wild; we virtually created the plant from wild kale through generations of cultivation. Does it stand to reason, then, that technically we did not evolve to consume broccoli, but instead that we altered the plant for our consumption? I realize that altering (or creating) a species through selective breeding is quite a different process than simply soaking or fermenting the current species. Nonetheless, can any parallel be drawn between the two? Can the intentional cultivation of modern vegetables be considered a method of processing?


  5. #25
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    Shine, some attribute cooking to be the a driver for the divergence of digestive tract of man and ape. Cooking allowed man to have a shorter, less active digestion than ape and allowed man to derive the energy from food more rapidly.


    I would guess that breeding is a processing technique, sort has the same goal -- get more out of the food.


    Dragon, you'll like this article. http://www.sciencedaily.com/releases...0810064914.htm

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  6. #26
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    I need to brush up on my anthropology; anybody know of a good website? I'd like to see a time-line for the advent of australopithecus, neanderthal, cro-magnon, use of fire, etc.


    I haven't covered this stuff since high school (30+ years ago!) so I'm a bit rusty.


    Shine, when people here talk about selective breeding, it's usually couched in negative terms. But wouldn't you think that that at least some of it is GOOD? The breeding of broccoli, for example, which is very nutrient dense and considered a super-food. Just saying "oh, such-and-such a food didn't exist before man developed it" (potatoes, for example) isn't really a valid argument for saying we shouldn't eat it.


  7. #27
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    Thanks for the link, Grandma. Yeah, that supports the idea that man HAS evolved greatly since discovering the use of fire. Wow, 1.9 million years ago? Seems like yesterday.


  8. #28
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    Here's an excerpt from that link which directly answers my initial question: How much time would it take for us humans to adapt to new food sources?


    "We strongly suspect hominids began using fire about 1.9 million years ago, when Homo erectus appeared," said Laden. "The evidence for fire this early is a bit tenuous, but once word got out about our idea, we were contacted by colleagues working in East Africa who are about to publish very strong evidence for human-controlled fire at a very early date. In any event, fire wouldn't have worked as a 'spark' to evolution if roots hadn't already been in the diet."


    According to Laden and his colleagues, both Lucy and Homo erectus ate tubers, but Lucy ate them raw. Thus, she and her australopithecine relatives had huge teeth and strong jaws. But with the advent of fire, hominids were able to cook tubers, which softened them, making chewing easier, and increased the amount of available nutrients. Teeth no longer had to be huge and suitable for constant chewing. Further, cooking allowed hominids to expand their diets. Many tubers are poisonous unless cooked, so cooking opened up new food sources. The use of tubers may have helped australopithecines expand their range from rainforest to savanna, where tubers were numerous.


  9. #29
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    Dragonmamma, check my latest post here: http://tinyurl.com/mnosy9

    “Every saint has a past and every sinner has a future.” -Oscar Wilde
    "The power of accurate observation is commonly called cynicism by those who have not got it." -George Bernard Shaw
    "The trouble with jogging is that the ice falls out of your glass." -Martin Mull

  10. #30
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    Ha, ha, I just did. (Tag! You're it.)


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