Human Evolution Enters an Exciting New Phase • Hacker News Board

Re: Human Evolution Enters an Exciting New Phase

#61

Post by hasenj » Fri, Nov 30, 2012, 5:26 AM UTC

> Akey specializes in what’s known as rare variation, or changes in DNA that are found in perhaps one in 100 people, or even fewer.

This classification of variations into "rare variations" and "common variation" is interesting (and new to me).

Any one knows resources that explain more about this?

Popular science depictions of "mutations" make them sound like "one lucky shot" kind of thing. This model never made sense to me. I figured these variations must be occurring constantly across the population.

It's interesting to me that even the variations which are considered "rare" actually occur at a rate that's around 1 in 100. Hell, even if it was 1 in a 1000, that's still quite a lot.

I need more resources about this topic!

Re: Human Evolution Enters an Exciting New Phase

#62

Post by baddox » Fri, Nov 30, 2012, 7:21 AM UTC

lotharbot wrote: post #54

baddox wrote: post #49

Earlier quoted context omitted.

> Natural selection only works if unfit individuals are killed off prior to breeding. That's not true. Even in the hypothetical scenario that all humans reproduced exactly enough to replace themselves then died immediately (i.e. a completely constant human population), there would almost certainly be gradual change in the inheritable traits of the human population (i.e. evolution). If sexual partners are chosen, and…

If genes change in proportion because they make people more or less likely to reproduce, that's "natural selection". If the genes change in proportion just due to randomness (they're all equally fit, but some were passed on more times than others as a fluke), we call it "genetic drift" [0]. Evolution involves mutation and gene flow [1] adding new genes to a population, and natural selection and genetic drift changing…

I didn't mention any changes due to random sampling. I was careful to qualify that the choice of mate is influenced by genes. Wouldn't that qualify as natural selection more than genetic drift? Although, now that I think of it, the two are probably more like directions on a continuum, since choice of mate would be influenced by both genes and random sampling. Is that accurate?

Re: Human Evolution Enters an Exciting New Phase

#63

Post by kristofferR » Fri, Nov 30, 2012, 8:58 AM UTC

maratd wrote: post #25

tmh88j wrote: post #21

Earlier quoted context omitted.

>It doesn't matter how hot, strong, or brilliant you are, if you have zero kids, from an evolutionary perspective ... it's the same as if you were killed and eaten by some wild animal. I don't agree with that 100% (the same as just dying part), solely because of the technology and globalization that we currently live with. Even if you don't have children, by simply starting a business where you employ many people, yo…

Experiments, both on humans and other animals, have repeatedly shown that there is no such thing as pure-as-white-snow altruism. Whatever appears to be altruistic is either a misfire (essentially error, in biological terms) or is found to be long-term self-interested behavior. That billionaire is giving his wealth away because he wants better social standing, etc. In the end, evolution doesn't favor altruism and we h…

Please don't spread the myth of Mother Teresa as an altruistic person, she was anything but.

She cared a lot about her missionary work, but not about the poor. In fact she believed that the suffering of the poor was a good thing and denied painkillers to be administered for that reason (while she was always receiving painkillers for her own medical issues). Sure, she funded a lot of what she called "houses of the dying" where people were left to die instead of often easily treated with antibiotics, but she only really cared about her missionary work.

Re: Human Evolution Enters an Exciting New Phase

#64

Post by lotharbot » Fri, Nov 30, 2012, 5:47 PM UTC

baddox wrote: post #62

lotharbot wrote: post #54

Earlier quoted context omitted.

If genes change in proportion because they make people more or less likely to reproduce, that's "natural selection". If the genes change in proportion just due to randomness (they're all equally fit, but some were passed on more times than others as a fluke), we call it "genetic drift" [0]. Evolution involves mutation and gene flow [1] adding new genes to a population, and natural selection and genetic drift changing…

I didn't mention any changes due to random sampling. I was careful to qualify that the choice of mate is influenced by genes. Wouldn't that qualify as natural selection more than genetic drift? Although, now that I think of it, the two are probably more like directions on a continuum, since choice of mate would be influenced by both genes and random sampling. Is that accurate?

If choice of mate is influenced by genes, and there's a difference in fitness level due to those genes, then it would be natural selection. That is, if Alice-Bob have more kids than Claire-Dave for genetic reasons, natural selection is favoring AB over CD.

If choice of mate is influenced by genes, but there's no difference in fitness level, then you're looking at a natural drift scenario. That is, if Alice-Bob have more kids than Claire-Dave due to some random effect like happening to meet much earlier in life, AB's gains over CD are classified as drift.

Both effects are usually present, but sometimes one is much more significant than the other.

Re: Human Evolution Enters an Exciting New Phase

#65

Post by robertk » Fri, Nov 30, 2012, 8:10 PM UTC

mahyarm wrote: post #59

robertk wrote: post #43

Earlier quoted context omitted.

Backups. If you can backup someone's brain (which should be doable in silicon), then even if they contract cancer, you can simply back them up for a few hundred years (or however long it takes) until there's a cure.

Oh I thought you meant the more literal substance, not making a software simulation reproduction.

Either way. I imagine silicon hardware that we intelligently designed would be easier to backup than messy biology we hardly understand.

Re: Human Evolution Enters an Exciting New Phase

#66

Post by jonathansizz » Mon, Dec 03, 2012, 5:03 PM UTC

baddox wrote: post #46

jonathansizz wrote: post #28

Earlier quoted context omitted.

And I can't stress enough that selection and evolution are not equivalent; selection is only one evolutionary force, and in humans probably not a very powerful one due to our historically low effective population size. Other forces in evolution include genetic drift, migration (gene flow) and mutation. As the article discusses, the major characteristics of human populations in the recent past centre around demographi…

Although there is obviously some debate among scientists, natural selection is considered to be the most important force by far .

By whom?

I suggest you read up on nearly neutral theory and think about the fate of nearly neutral mutations (the vast majority) in groups with small effective population size (like humans).