5 ms·

I can think of another reason why European explorers didn't see any maimed, weak, diseased or decrepit hunter-gatherers: they died. Do I know if that's how it

I can think of another reason why European explorers didn't see any maimed, weak, diseased or decrepit hunter-gatherers: they died. Do I know if that's how it happened or not? No. But neither does the author. Also, to say that "We are not designed for these (post-hunter-gatherer) foods" is to ignore any changes that may have occurred in the last 10 000 years or so.

Scriptor 17y ago
It's a valid idea. It would be nice to see some population figures and see if they are any lower than any other groups of people who lived under similar conditions.
philwelch 17y ago
Hominids have been around for millions of years. Agriculture started 10,000 years ago but it wasn't until millennia after that until most of the human race lived in civilizations. So really, the effects of civilization on our biological evolution is negligible compared to the effects of hunting and gathering, isn't it? Evolution leaves a lot of cruft behind. It never refactors. Humans have fantastic pectoral muscles because we evolved from brachiating primates, for instance. It's no coincidence that human children hang from monkey bars or that we can stretch our arms far overhead and support ourselves hanging from them.
- barry-cotter 17y ago
  Not wrong but misleading. Agriculture lead to a massive increase in effective population size and in selection parameters, some of which were very strong and sustained. The higher population means more mutations which means more raw material to work with in terms of potential beneficial mutations. As for recently selected alleles the canonical example is probaaly lactose tolerance. You can make a good case its behind the spread of the I-E language family. As another example alcohol tolerance, better tolerance for high starch diet and lower levels of ADD in populations with long histories of agriculture. Contrast recent hunter-gatherers like Oz aboriginies or 'nesians with Europeans or Chinese. Diabetes, alcoholism, poor educational outcomes because of the ADD and other things. AFAIK ADD is practically unknown among East Asians, subsistence rice farming and more than a millenium of civil service exams as social mobility would both select against it.
  - Retric 17y ago
    10,000 years is a blink in the eye in terms of human evolution. The problem is the time it takes people to have children. Assuming the average parent is 20, and you go back 20 generations (1000 years) you only have 1 million ancestors which is still a small subset of the population. Thinking in the other direction useful mutations only spread as they help people survive longer / have more children so the change is normally vary slow. If anything the shift to agriculture has reduced genetic diversity as stuff that had little impact on hunter gatherers are culled from a civilized society. PS: Alcoholism is actually the default, populations with a long history of alcohol use have far less Alcoholism. However, it's far from eliminated in society's that have been using Alcohol for thousands of years.
    - barry-cotter 17y ago
      Re:alcoholism, yes that was whajt I was trying to say, apologies if I was unclear. But as for fast genetic change 99% or so of Danes are lactose tolerant. Among Chinese less than 5. Agricultural populations will only have less variation than h-gs due to population bottlenecks or if a h-g variant is selected against in an agricultural environment. For a small effect gene assume a 1% higher survival rate. I'm not really up on the maths but with 10k years with 25 year generation time we have 400 generations. I think that's plenty of time to reach fixation. If I was at a computer instead of doing this at my phone I'd do it properly, but if you google the Hardy-Weinberg equation something useful should come up. As a thought experiment consider the polynesian migrations. Assume that given the longer distance between islands each migration event between islands culls thd weakest 20% so each new founder population has a higher mean muscle mass. That's a one generation selection a lot higher than 1%. With 5 such events it wouldn't surprise me if you moved 1or 2 standard deviations in the mean. Look at the difference in physiogonomx between native Taiwaneese and Maori. Less than 1000 years in those migrations, IIRC.
  - philwelch 17y ago
    ADD is pretty much the deepest evolutionary change that would have happened to humans post-agriculture. I'm not sure if lactose tolerance is genetic, or if it is the result of acidophilus symbiosis (or both?) Here's a couple other nitpicks: 1. Lots of white people have ADD 2. Lots of East Asians are descended from the Mongols, who were hunter-gatherers well into medieval times.

Scriptor 17y ago

It's a valid idea. It would be nice to see some population figures and see if they are any lower than any other groups of people who lived under similar conditions.

philwelch 17y ago

Hominids have been around for millions of years. Agriculture started 10,000 years ago but it wasn't until millennia after that until most of the human race lived in civilizations. So really, the effects of civilization on our biological evolution is negligible compared to the effects of hunting and gathering, isn't it? Evolution leaves a lot of cruft behind. It never refactors. Humans have fantastic pectoral muscles because we evolved from brachiating primates, for instance. It's no coincidence that human children hang from monkey bars or that we can stretch our arms far overhead and support ourselves hanging from them.

barry-cotter 17y ago
Not wrong but misleading. Agriculture lead to a massive increase in effective population size and in selection parameters, some of which were very strong and sustained. The higher population means more mutations which means more raw material to work with in terms of potential beneficial mutations. As for recently selected alleles the canonical example is probaaly lactose tolerance. You can make a good case its behind the spread of the I-E language family. As another example alcohol tolerance, better tolerance for high starch diet and lower levels of ADD in populations with long histories of agriculture. Contrast recent hunter-gatherers like Oz aboriginies or 'nesians with Europeans or Chinese. Diabetes, alcoholism, poor educational outcomes because of the ADD and other things. AFAIK ADD is practically unknown among East Asians, subsistence rice farming and more than a millenium of civil service exams as social mobility would both select against it.
- Retric 17y ago
  10,000 years is a blink in the eye in terms of human evolution. The problem is the time it takes people to have children. Assuming the average parent is 20, and you go back 20 generations (1000 years) you only have 1 million ancestors which is still a small subset of the population. Thinking in the other direction useful mutations only spread as they help people survive longer / have more children so the change is normally vary slow. If anything the shift to agriculture has reduced genetic diversity as stuff that had little impact on hunter gatherers are culled from a civilized society. PS: Alcoholism is actually the default, populations with a long history of alcohol use have far less Alcoholism. However, it's far from eliminated in society's that have been using Alcohol for thousands of years.
  - barry-cotter 17y ago
    Re:alcoholism, yes that was whajt I was trying to say, apologies if I was unclear. But as for fast genetic change 99% or so of Danes are lactose tolerant. Among Chinese less than 5. Agricultural populations will only have less variation than h-gs due to population bottlenecks or if a h-g variant is selected against in an agricultural environment. For a small effect gene assume a 1% higher survival rate. I'm not really up on the maths but with 10k years with 25 year generation time we have 400 generations. I think that's plenty of time to reach fixation. If I was at a computer instead of doing this at my phone I'd do it properly, but if you google the Hardy-Weinberg equation something useful should come up. As a thought experiment consider the polynesian migrations. Assume that given the longer distance between islands each migration event between islands culls thd weakest 20% so each new founder population has a higher mean muscle mass. That's a one generation selection a lot higher than 1%. With 5 such events it wouldn't surprise me if you moved 1or 2 standard deviations in the mean. Look at the difference in physiogonomx between native Taiwaneese and Maori. Less than 1000 years in those migrations, IIRC.
- philwelch 17y ago
  ADD is pretty much the deepest evolutionary change that would have happened to humans post-agriculture. I'm not sure if lactose tolerance is genetic, or if it is the result of acidophilus symbiosis (or both?) Here's a couple other nitpicks: 1. Lots of white people have ADD 2. Lots of East Asians are descended from the Mongols, who were hunter-gatherers well into medieval times.