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Why believe that it takes thousands of years to select and enhance a gene? We have selectively bred animals in decades to exhibit traits that were useful, and

by douche 11y ago

Why believe that it takes thousands of years to select and enhance a gene? We have selectively bred animals in decades to exhibit traits that were useful, and long before we had any concept of genetics. We have evidence of the production of beer dating back before the Pyramids - and beer and wine were staples of pre-modern diets in the old world, that everyone drank, at least in the form of watered wine and small-beer, as the drinking water all-too-often would kill you. Why should we not expect to see genetic adaptation in such an environment?

sandworm101 11y ago
You are skipping through a few steps. The gene has to first appear. It has to be one of those many tiny little perturbations that appear every so often. It then has to give that organism some sort of advantage. For a gene controlling alcoholism, it would have to appear somewhere where alcoholism had some substantial impact on survivability ... and then spread out across europe, asia and africa giving some similar advantage to persons along the way else it die out. I might be open if the old world suffered from widespread alcoholism (to the point of impacting survivability across classes) for the last 20,000 years, but is just didn't. Producing alcohol takes proper effort and resources. You only get there one you aren't starving anymore. Egypt and a few other areas capable of sustaining intensive agriculture were not the norm.
- jerf 11y ago
  "For a gene controlling alcoholism, it would have to appear somewhere where alcoholism had some substantial impact on survivability" No, it doesn't. It needs to be a gene that has an impact on alcoholism, but the thing being selected for could be something else entirely. Consider sickle-cell anemia. If you just look at it as the "sickle-cell anemia gene" you'll boggle at how it spread as far as it did, but that's because it's also the "malaria-resistance gene". If alcohol is introduced into a population that did not have widespread, ready access to it for long time frames, there's no guessing in advance what could happen as it interacts with arbitrary other adaptations that have never "seen" alcohol before. I want to point out you keep boggling at how intrinsically impossible this all is, and I keep citing concrete examples of very similar things that happen. And I'll reiterate that my point is that it was a viable theory, until the facts contradicted it, not that it was certainly correct and certainly not that it's correct now. Simply that it was not a stupid theory. (Indeed, given that this is just one study I'd be glib even saying it's "disproved", it's merely one that we must Bayesian-update to a much smaller probability. But I wouldn't downgrade it to zero quite yet. We've got a lot of gene science left to learn. And as always happens, when we take a closer look, it always turns out to be more complicated than we thought...)

by douche 11y ago

sandworm101 11y ago

You are skipping through a few steps. The gene has to first appear. It has to be one of those many tiny little perturbations that appear every so often. It then has to give that organism some sort of advantage. For a gene controlling alcoholism, it would have to appear somewhere where alcoholism had some substantial impact on survivability ... and then spread out across europe, asia and africa giving some similar advantage to persons along the way else it die out. I might be open if the old world suffered from widespread alcoholism (to the point of impacting survivability across classes) for the last 20,000 years, but is just didn't. Producing alcohol takes proper effort and resources. You only get there one you aren't starving anymore. Egypt and a few other areas capable of sustaining intensive agriculture were not the norm.

jerf 11y ago
"For a gene controlling alcoholism, it would have to appear somewhere where alcoholism had some substantial impact on survivability" No, it doesn't. It needs to be a gene that has an impact on alcoholism, but the thing being selected for could be something else entirely. Consider sickle-cell anemia. If you just look at it as the "sickle-cell anemia gene" you'll boggle at how it spread as far as it did, but that's because it's also the "malaria-resistance gene". If alcohol is introduced into a population that did not have widespread, ready access to it for long time frames, there's no guessing in advance what could happen as it interacts with arbitrary other adaptations that have never "seen" alcohol before. I want to point out you keep boggling at how intrinsically impossible this all is, and I keep citing concrete examples of very similar things that happen. And I'll reiterate that my point is that it was a viable theory, until the facts contradicted it, not that it was certainly correct and certainly not that it's correct now. Simply that it was not a stupid theory. (Indeed, given that this is just one study I'd be glib even saying it's "disproved", it's merely one that we must Bayesian-update to a much smaller probability. But I wouldn't downgrade it to zero quite yet. We've got a lot of gene science left to learn. And as always happens, when we take a closer look, it always turns out to be more complicated than we thought...)