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Science

How Farming Reshaped Our Genomes 144

sciencehabit writes "The earliest farmers may not have been built for the profession. They may have been unable to digest starch and milk, according to a new ancient DNA study of a nearly 8000-year-old human skeleton from Spain (a hunter-gatherer who had dark skin and blue eyes). But these pioneers did already possess immune defenses against some of the diseases that would later become the scourge of civilization. The findings are helping researchers understand what genetic and biological changes humans went through as they made the transition from hunting and gathering to farming."
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How Farming Reshaped Our Genomes

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  • Why is he unkempt? (Score:5, Insightful)

    by BobMcD ( 601576 ) on Monday January 27, 2014 @02:12PM (#46083583)

    http://news.sciencemag.org/sit... [sciencemag.org]

    Who says he let his hair and beard grow long? What evidence from the skeleton would have led to this conclusion?

    • by ackthpt ( 218170 )

      http://news.sciencemag.org/sit... [sciencemag.org]

      Who says he let his hair and beard grow long? What evidence from the skeleton would have led to this conclusion?

      Good ol' science, the kind where we immediately imagine things in our own image (he types as he strokes his luxuriant beard.)

    • by pesho ( 843750 ) on Monday January 27, 2014 @02:15PM (#46083617)
      The five blade flint stone razor blade has not been invented yet.
      • Re: (Score:2, Interesting)

        by Anonymous Coward

        You don't seem to realize a flint edge is actually much sharper than any metal blade -- that's why they use silica tips in atomic force microscopes; the tip is only a few atoms wide.

        People used to be very, very good at chipping flint blades.

        You may think a piece of plastic with one or metal blades will shave better, but you'd be wrong.

        • If you can demonstrate your assertion I would like to purchase one of your flint edged shaving razers. My face tears up metal blades in no time.

          • by Tablizer ( 95088 )

            If you can demonstrate your assertion I would like to purchase one of your flint edged shaving razers. My face tears up metal blades in no time.

            That's because you have farmer skin.

        • You're thinking of obsidian blades. Flint can be made quite sharp, but not as good as modern steel knives. Obsidian fracture edges can be one molecule thick.
      • While funny, a simple flake would be sharp enough. Or for that matter, the smoldering end of a burnt twig for beard and mustache shaping.
    • Re: (Score:2, Informative)

      by netsavior ( 627338 )
      Because shaving was all but impossible before metal tools that could be sharpened enough to actually shave... copper tools were some 3000 years after this fossil.
      • Maybe they used fire?
        • you try to burn your facial hair off, let me know how that works for you
          • by Arker ( 91948 ) on Monday January 27, 2014 @03:16PM (#46084373) Homepage

            There are actually a handful of tribes that had that custom, the Yahi in california come to mind immediately. Plucking is also useful. But as a couple of other posters pointed out, the point about no shaving was specious to begin with. A high quality flint scraper is actually sharper than the best metal razor and yes they work just fine for shaving, if you are inclined to that activity.

            We really have zero evidence as to what the custom was in the time/space coordinates where the skeleton originates, so his personal grooming style and habits are entirely conjectural. Someone just thought he would look good as a hairy wildman so that is how he was painted.

          • It's a real method that has been used for at least hundreds of years and is still practiced today. It's not a clean shaving method but it is one way to get rid of excess hair without the use of a tool.
          • That's probably how Greek woman removed there pubic hair.
          • As I pointed out elsewhere, use the smouldering end of a twig. Singing was routinely practiced until the early 1900's, even in the US. Worked fine apparently.
      • by E++99 ( 880734 ) on Monday January 27, 2014 @02:32PM (#46083811) Homepage

        Flynt is sharper than any copper knife.
        Obsidian is sharper than any copper knife.
        Tribal people shave with flint to this day.
        There is archaeological evidence of shaving going back 20,000 years.

      • obsidian and flint both are sharp enough to cut hair

      • by BobMcD ( 601576 )

        Even if this were true, and I rather doubt it is, I didn't ask why he wasn't bald.

        We're assuming he was primitive and savage. Do we have science behind that or no?

    • by Moheeheeko ( 1682914 ) on Monday January 27, 2014 @02:31PM (#46083801)
      Prehistoric spain was fucking cold, why would he remove a natural head covering?
    • Because he had shaggy hair and a beard before it was cool.

    • Re: (Score:2, Funny)

      by Anonymous Coward

      http://news.sciencemag.org/sit... [sciencemag.org]

      Who says he let his hair and beard grow long? What evidence from the skeleton would have led to this conclusion?

      Look, they found him with a "Cobal Programming in UNIX for Dummies" book. What more evidence do you need?

    • by jellomizer ( 103300 ) on Monday January 27, 2014 @03:27PM (#46084521)

      Beards were rather popular in Ancient culture. A sign of manhood and variability. It took Alexander the Great to change that trend, pointing out that a beard could be grabbed in battle, so he ordered his troops to shave them off.
      However, it is a good way to protect your face, while hiding in bushes, and keeps your face warmer in the winter. It makes sense to assume that Hunters (Males) would have beards.

      • by BobMcD ( 601576 )

        I still think he may have fashioned/cut his hair and or beard in some way, rather that just letting it go wild.

    • Why is he unkempt?

      No more unkempt than a Unix programmer of yore. I wonder if he wore sandals with socks?

    • by ignavus ( 213578 )

      http://news.sciencemag.org/sit... [sciencemag.org]

      Who says he let his hair and beard grow long? What evidence from the skeleton would have led to this conclusion?

      They found a selfie on a nearby fossilized cellphone.

  • by ackthpt ( 218170 ) on Monday January 27, 2014 @02:13PM (#46083599) Homepage Journal

    It means not being too choosy what you om-nom-nom on when the going is lean. Which likely means eating things which may have various parasites, mold spore, other fungi, even partially decomposed. "What luck! A partially decomposed squirrel with red rashes all over its body! Num!" That which didn't kill them, indeed make them stronger (those which survived, that is.)

    In today's scrubby, scrub scrubbed world of clean, inspected and otherwise near perfect world of meat, dairy and produce, we're not challenging our bodies very much. Further, we appear to be adapting to eating sugary, fried or other highly processed food, which means we say "Ewww!" when presented with ethnic foods we haven't seen before, which include the globby or wiggly bits of animals we don't see in the meat case at the market (which traditionally were the best parts, unlike the muscle which was often left behind.)

    Somewhat disconcerting how we haven't turned into beings which are entirely fed by capsule, a la the Jetsons "Oh, dear, I've overcooked the steak and potatoes pill."

    Fortunately, infants keep picking up dead bugs off the carpet and chewing on them, which gives them some bit of a test in developing their immune systems.

    • And for people like you there's the Road Kill Grill http://johnmullsmeats.com/road... [johnmullsmeats.com]

      I, on the other hand, am ok with taking antihistamines (and the advances of science generally) instead of intestinal parasites to keep my allergies under control.

    • by m00sh ( 2538182 )

      It means not being too choosy what you om-nom-nom on when the going is lean. Which likely means eating things which may have various parasites, mold spore, other fungi, even partially decomposed. "What luck! A partially decomposed squirrel with red rashes all over its body! Num!" That which didn't kill them, indeed make them stronger (those which survived, that is.)

      In today's scrubby, scrub scrubbed world of clean, inspected and otherwise near perfect world of meat, dairy and produce, we're not challenging our bodies very much. Further, we appear to be adapting to eating sugary, fried or other highly processed food, which means we say "Ewww!" when presented with ethnic foods we haven't seen before, which include the globby or wiggly bits of animals we don't see in the meat case at the market (which traditionally were the best parts, unlike the muscle which was often left behind.)

      Somewhat disconcerting how we haven't turned into beings which are entirely fed by capsule, a la the Jetsons "Oh, dear, I've overcooked the steak and potatoes pill."

      Fortunately, infants keep picking up dead bugs off the carpet and chewing on them, which gives them some bit of a test in developing their immune systems.

      Nobody knows what was going on then. Everyone (the Paleo community included) stop saying how you know humans lived so and so many years ago.

      For all we know, they had an organic food paradise. Fresh fruits and vegetables right off the plants and fresh just-slaughtered grass fed meat to eat.

      • Actually, that *is* how they lived. You just neglected the part about the rest of the world trying to kill them during acquisition.
      • by ackthpt ( 218170 ) on Monday January 27, 2014 @04:21PM (#46085193) Homepage Journal

        Nobody knows what was going on then. Everyone (the Paleo community included) stop saying how you know humans lived so and so many years ago.

        For all we know, they had an organic food paradise. Fresh fruits and vegetables right off the plants and fresh just-slaughtered grass fed meat to eat.

        Rather like you can read the life of a tree by its rings, you can tell a lot about the diets of people by the condition of their teeth at death, build of their bones and some of the elemental composition. Science is more scientific than ever, which is cursed on a regular basis by those who won't credit it.

      • by cusco ( 717999 )

        Nobody knows what was going on then.

        We know exactly what they ate and how it was prepared. We have their copralites, their fossilized crap. We have their homes. We have their garbage dumps. We have their skeletons. It's not deep dark mystery, basic scientific analysis of human remains can let us know how far they traveled from their birthplace (isotopic analysis of bone growth), how often they experienced food shortages (bone density), what type of diet they had (trash midden excavation), what intesti

      • actually, we know man and his ancestors were cooking for 250,000 at least

    • ...we appear to be adapting to eating sugary, fried or other highly processed food...

      I wouldn't consider epidemic rates of diabetes, cancer, heart disease and obesity "adaptation".

      • Those are major now prevalent in our culture because we've basically done away with the things that typically killed you first. Things that killed you more horribly and with greater percentages of the population, by the way.

        It's not epidemic, it's disclosure.
      • by ackthpt ( 218170 )

        ...we appear to be adapting to eating sugary, fried or other highly processed food...

        I wouldn't consider epidemic rates of diabetes, cancer, heart disease and obesity "adaptation".

        Yet some people eat horribly unhealthy and live to their 80s or 90s, while others religiously dine on healthy foods and die of cancer, contract diabetes or other such maladies. Don't imagine there isn't some evolution at work here. Those who can adapt, will and when their food of choice vanishes they suffer terribly.

        • How does evolution shape a species when almost everyone makes it past the age of raising children? No matter what life style you choose, apart from some very destructive ones, you are most likely going to live to at least 50. By that time your kids are pretty much grown. Any bad genes you had have already been transferred to your offspring.
    • Further, we appear to be adapting to eating sugary, fried or other highly processed food, which means we say "Ewww!" when presented with ethnic foods we haven't seen before

      Who is this "we" you are talking about?

    • by hey! ( 33014 )

      I don't think this is entirely right. You'd see this scavenging behavior in modern hunter gatherer societies.

      I think we tend to conflate a lot of things that nature of course does not, e.g. health and longevity with local carrying capacity. Paleolithic humans were evidently a very healthy bunch, judging from the skeletons they left behind. They were slightly taller than humans are today, and had a life expectancy that was unequalled until the 20th Century. This is indicative of a very high quality diet

  • by zooblethorpe ( 686757 ) on Monday January 27, 2014 @02:16PM (#46083631)

    What is this silliness, that "humans" in the broad, blanket sense could not digest starch? Feh.

    We already know from analysis of Neanderthal remains that they could digest starch, and did in fact eat things like starchy tubers and grains. [google.com] By 8000 years ago, it's generally accepted that the Neanderthals were no more, at least as a distinct population, and that any remaining Neanderthal-specific genes had been absorbed by the wider Cro Magnon population. (Interestingly, it sounds like the Neanderthal genes might give their descendants, i.e. non-sub-Saharan-Africa humans, extra resistance to viral infection. [discovermagazine.com])

    This study, where evidence from one individual is extrapolated to the entire human population, sounds silly in the extreme. "One Size Fits All!" never really does.

    Cheers,

    • by geekoid ( 135745 )

      Yes, but this evidence points to that may be wrong.

      • This is the equivalent of me saying all humans cannot process lactose or gluten because I cant. Everyone is different.
    • by goombah99 ( 560566 ) on Monday January 27, 2014 @02:34PM (#46083849)

      All mammals are, by definition, born with the ability to digest milk, therefore they have the genes to do that. It can happen that those genes are epi-genitically turned off in adults that are not exposed to milk. However, the genes would be still there.

      Thus I'm extremely doubtful that any genetic studies could have revealed the lack of milk digesting genes. And since I don't see how they could assess any epi-genetic state of a long dead individual I really wonder about how they arrived at that conclusion.

      • by Baloroth ( 2370816 ) on Monday January 27, 2014 @02:53PM (#46084053)

        All mammals are, by definition, born with the ability to digest milk, therefore they have the genes to do that. It can happen that those genes are epi-genitically turned off in adults that are not exposed to milk. However, the genes would be still there.

        The genes for digestion are still there, yes, but they shut off after childhood unless you have a specific genetic mutation that allows lifelong production of lactase. Source 1 [nih.gov], source 2 [nih.gov].

        • by Tablizer ( 95088 )

          Mine shut off at about 35 years of age (European descent). Odd.

        • This would make sense though since only a baby typically would drink fresh milk unless you refrigerate it. If you leave fresh milk out the bacteria and enzymes in the milk and environment quickly digest the sugars (on the order of hours) and ferment the milk which also helps preserve it.

    • by m00sh ( 2538182 )

      What is this silliness, that "humans" in the broad, blanket sense could not digest starch? Feh.

      We already know from analysis of Neanderthal remains that they could digest starch, and did in fact eat things like starchy tubers and grains. [google.com] By 8000 years ago, it's generally accepted that the Neanderthals were no more, at least as a distinct population, and that any remaining Neanderthal-specific genes had been absorbed by the wider Cro Magnon population. (Interestingly, it sounds like the Neanderthal genes might give their descendants, i.e. non-sub-Saharan-Africa humans, extra resistance to viral infection. [discovermagazine.com])

      This study, where evidence from one individual is extrapolated to the entire human population, sounds silly in the extreme. "One Size Fits All!" never really does.

      Cheers,

      Or they could have been using something starchy as a toothbrush.

  • by kruach aum ( 1934852 ) on Monday January 27, 2014 @02:21PM (#46083673)

    makes breasts a curious adaptation.

    • You're confusing the milk from other animals with human breast milk.

      Humans can - and have, historically - use that as their sole food source up to 5 years old.

      The problem arises from using milk from other creatures.

      • No, the ambiguity lies in the summary (and possibly TFA). I posted to point out the absurdity.

      • You're confusing the milk from other animals with human breast milk.

        Humans can - and have, historically - use that as their sole food source up to 5 years old.

        The problem arises from using milk from other creatures.

        THe article says they could not process lactose, the major carbohydrate in all milk, human and otherwise. So no this is not about processing the species specific milk, but milk in general. That's too surprising to be credible without further explanation-- mammal infants live on milk.

    • by Anonymous Coward

      TFA says lactose. AFAIK human milk carbs are mainly lactose but the "hind milk" (that comes after feeding a little while) includes the lactase enzyme needed to digest it.

    • by alvinrod ( 889928 ) on Monday January 27, 2014 @02:52PM (#46084037)
      The composition of the milks are different. Cow milk contains more protein in general, and some proteins that are not found in human milk. Some people are unable to process those proteins. Also, intolerance to milk of any kind generally occurs later in life. If an individual were not able to digest it in infancy they would die and their genes would not be passed on. Perhaps with modern medical science, they would live, but this would not have been the case thousands of years ago.
      • by orient ( 535927 )
        My friend's kid is intolerant to some component in the milk found in North American stores - at least Canada and US. However, he has no issue drinking milk originating from Central and Eastern Europe.
    • by Valdrax ( 32670 ) on Monday January 27, 2014 @03:15PM (#46084361)

      Humans, like most mammals, can universally digest lactose in childhood. Also, like most mammals, the gene for producing lactase largely shuts down in adulthood, since in nature, it's largely unneeded and a waste of energy resources. People descended from milk-drinking cultures (mostly Europeans) have variations of a gene that prevent lactase production from turning off in adulthood.

      Of course, this has little to nothing to do with breasts, since humans are the only primates that have visible breasts when not nursing their newborn young, and even then they are much, much smaller than in humans. It's most likely they exist purely for sexual signalling (like a peacock's tail), since their size is mostly irrelevant to their function in child-rearing.

      • since humans are the only primates that have visible breasts when not nursing their newborn young, and even then they are much, much smaller than in humans. It's most likely they exist purely for sexual signalling

        Though it must also be pointed out that other primates have mouths that stick out while human's have theirs set back below their noses, and therefore humans need something to stick out in order to suck on it. Of course, breasts are way to big for that to be the sole driving factor in their development, and I would blame sexual signalling for getting them to the size that they are.

      • It is possible that humans just have more babies than other primates. Size definitely does matter for milk production. We might have ridiculously enlarged breasts for primates, but we have tiny breasts compared to some other mammals.
        Possibly we are just more fertile, or more likely to use wet-nurse babysitters throughout history?
        And we have to remember, not all cultures have any interest at all in breasts. If it is not even close to universal today, we have no reason to believe that they were sexualised at

        • Size definitely does matter for milk production

          Nope. The size (when not breastfeeding) is from the amount of fatty tissue, which is unrelated to the amount of milk-producing glandular tissue. It's possible to have not enough glandular tissue but it's very rare and takes insignificant space (enough glandular tissue to nurse exists in flat chested women).

          Higher fertility wouldn't explain things because 97% of the time, humans have only one child at a time. And humans make enough milk for twins anyway, even conveniently having two breasts for simultaneo

          • "97% of the time, humans have only one child at a time."
            Depends. Did the average human 100,000 years ago breastfeed until 12 years old, or until 6 months old. I doubt that we have any idea.

            • by Valdrax ( 32670 )

              Did the average human 100,000 years ago breastfeed until 12 years old, or until 6 months old. I doubt that we have any idea.

              Hunter-gatherer populations are a good proximate for human behavior that long ago. It varies by culture, but the average seems to be 3-5 years of age. Inuit are kind of an outlier at 7 years of age, but it makes sense given their environment. That's also about the same age at which most non-agricultural societies considered it safe to raise another child. Infanticide is common as a means of birth control until that age.

              It is interesting though that we didn't evolve a means of controlling fertility until

      • This doesn't necessarily mean humans didn't drink milk. If you leave milk out for any period of time it naturally ferments into yogurt (or something similar). This process the bacteria converts the lactose into lactic acid. This acid then denatures the proteins which is why yogurt is more of a gel. Many people that can't drink milk have no problem eating fully fermented milk products.

  • Far too many think that evolution is a relatively simple thing. A bit of radiation, some changes, and then genetic selection occurs. Nothing could be further from the truth. Our DNA is designed to solve the radiation issues (otherwise, you get cancer and die quickly). Instead, there are a large number of unknown virus that move from eukaryote to eukaryote. It will take a sequence of genes from one species, to another. Basically, animals that are in close contact will get genes from the other.

    One of the i
    • Unless of course the new colony is in an environment filled with new wildlife that also uses DNA. If that happened to be the case then we could possibly see evolution in progress.

  • I can't get the "dark skin and blue eyes" link to work.
  • by Irate Engineer ( 2814313 ) on Monday January 27, 2014 @04:32PM (#46085327)
    Remains have been found of the first known lactose-intolerant celiac! Research is continuing, but he may have died of starvation as he had to send all his restaurant dishes back to the kitchen for including allergens. A compounding factor was all of his friends wouldn't eat out with him anymore because it was such a picky eater.
  • That must be the "Old MacDonald had a Farm" genome ...or Mr. Green Genes.

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