Is the Human Race still evolving?

[fudgefactorfive]

There is less selection present.

I gave you "long" - now I'll try "short" - no there isn't

We're not having sex less. So there's loads of sexual selection going on. And we're not dying any less. So there's loads of natural selection going on.

Be very careful where this line of thinking ("we are not improving ourselves any more, we are letting all sorts of weaker dross into the population") takes you. Some people use it to justify all kinds of horrific superfascist eugenicist arguments.

 

[Bob_the_lost]

You'd have a very hard time proving that since there are billions upons billions of selection events of a kind every day. The way of thinking about selection that tends to lead from the survival of the fittest trope is to treat it as synonymous with events leading to the death of individuals. But it's only marginally related to death. Selection is whatever changes the relative frequency of alleles in a population. Anything that marginally affects anyone's chance of having children (or supporting others in having children) and is in turn influenced by genes is a selection event.
Some kinds of obvious selection events now have a reduced selective effect for some of us (e.g my genetically-influenced susceptibility to polio doesn't mattter quite as much as it would've 60 years ago) but other, less obvious, selection events are still out there...

Selection (as i'm using the term) being people not making it to breeding age, or not breeding for another reason. People dying before they make it to the point of breeding is less of a factor thanks to modern medicine (hell even victorian age medicine makes a massive difference), unless you can show that societal effects (etc.) have become greater to outweigh that then my point stands.

 

[tastebud]

Selection is whatever changes the relative frequency of alleles in a population.

I've quoted this part to hammer the point home.

 

[Bob_the_lost]

we're not dying any less. So there's loads of natural selection going on.

You know that's bullshit. Everyone dies, but not everyone dies before bearing children.

People are living to breed more. Thus i'm right and you're wrong, hence i shall use this smilie:

 

[chooch]

Selection (as i'm using the term) being people not making it to breeding age, or not breeding for another reason

Fancy making a list of all the genetically-influenced stuff that would affect this?
I wouldn't.

 

[Bob_the_lost]

Fancy making a list of all the genetically-influenced stuff that would affect this?
I wouldn't.

Haemophillia, cystic fibrosis, sickle-cell anemia, infertillity, not to mention that if you're one of the poor sods who's got a genetic predisposition to something like polio or any other disease that can hit children.

 

[Nickster]

Haemophillia, cystic fibrosis, sickle-cell anemia, infertillity, not to mention that if you're one of the poor sods who's got a genetic predisposition to something like polio or any other disease that can hit children.

I have a genetic predisposition not to get past the first date without making a twat of myself - hence not having bred!

 

[chooch]

Ginger hair, depression, a happy go lucky attitude to contraception, a not so hapy go lucky attitude to contraception, predisposition to violence, socially approved looks, susceptibility to young onset cancers, lack of susceptibility to some religions, risk taking behaviour, very high IQ, very low IQ, fecundity, height, talent, being born into a low status group, being born into a high status group, not liking children, being born into a society that has low infant mortality and a good pension system, not being born into a society that has low infant mortality and a good pension system, etc. etc. etc.

 

[fudgefactorfive]

People are living to breed more.

You sure about that?

Even if it's true, which I doubt, surely "breeding more" is "selecting more"? Or is it only selection when it suits your criteria for "improvement"?

 

[Bob_the_lost]

Ginger hair, depression, a happy go lucky attitude to contraception, a not so hapy go lucky attitude to contraception, predisposition to violence, socially approved looks, susceptibility to young onset cancers, lack of susceptibility to some religions, risk taking behaviour, very high IQ, very low IQ, fecundity, height, talent, being born into a low status group, being born into a high status group, not liking children, being born into a society that has low infant mortality and a good pension system, not being born into a society that has low infant mortality and a good pension system, etc. etc. etc.

And? I don't have to prove that society has no effect (edit: good thing too otherwise i'd be in trouble), just that medicine does.

Y=F(I) + G(J)

If F(I) = 0 then for Y to remain unchanged G must increase.

 

[Bob_the_lost]

You sure about that?

Even if it's true, which I doubt, surely "breeding more" is "selecting more"? Or is it only selection when it suits your criteria for "improvement"?

I am sure that more people, in both absolute and proportional terms, are making it to breeding age than they were 100 years ago (when there was already the basics of medicine). Far, far more than 1000 years ago.

If you want to dispute historical record then by all means make a fool of yourself.

Who the hell ever mentioned improvement? Who ever mentioned my criteria? Who the hell even implied that selection was a good thing?

Selection is about some breeding more than others. Everyone breeding equally would be a complete lack of selection, one group breeding more than another would be the same as the first case.

 

[fudgefactorfive]

I am sure that more people, in both absolute and proportional terms, are making it to breeding age than they were 100 years ago (when there was already the basics of medicine). Far, far more than 1000 years ago.

If you want to dispute historical record then by all means make a fool of yourself.

Who the hell ever mentioned improvement? Who ever mentioned my criteria? Who the hell even implied that selection was a good thing?

Selection is about some breeding more than others. Everyone breeding equally would be a complete lack of selection, one group breeding more than another would be the same as the first case.

Calm down, mate.

Yes, (ever so slightly) more people are making it to breeding age than they were in the Dark Ages. But are more people breeding? I don't think so.

Did anything that people said about alleles and what "selection" entails actually make any impact on you? Or did I really waste my time with that thousand-word essay?

 

[chooch]

Ugh. keep getting logged out.
Even if it were true that improvements in hygeine and medicine outweigh all other possible selection pressures (many of which are only able to come into play significantly because fewer of us rich folk are dying young or childless) then those too would be selection pressures, changing the genetic makeup of the population compared to a counterfactual population. i.e. we'd be evolving.

 

[Bob_the_lost]

Calm down, mate.

Yes, (ever so slightly) more people are making it to breeding age than they were in the Dark Ages. But are more people breeding? I don't think so.

Did anything that people said about alleles and what "selection" entails actually make any impact on you? Or did I really waste my time with that thousand-word essay?

*Becomes calm*

I read it, but it's not new to me. (Some of it's slightly wrong by the way, the bit about mutation for example is a bit too Xmen). I was fairly good at biology at school and did a humanties option that had a lot of study on the topic.

But you're still wrong when you use the term "slightly".

For the world, and for both Less Developed Countries (LDCs) and More Developed Countries (MDC) IMR declined significantly between 1960 and 2001. World infant mortality rate declined from 198 in 1960 to 83 in 2001.

Edit: Also it's not up for debate that more people are breeding now than 100 years ago, world population trends and birthrates will show that well enough.

 

[Bob_the_lost]

Ugh. keep getting logged out.
Even if it were true that improvements in hygeine and medicine outweigh all other possible selection pressures (many of which are only able to come into play significantly because fewer of us rich folk are dying young or childless) then those too would be selection pressures, changing the genetic makeup of the population compared to a counterfactual population. i.e. we'd be evolving.

Yes we would, however my current point is that it's being slowed by medicine. It doesn't have to be the only cause, or even the single greatest cause just that it is a cause, and one that is being negated to some extent.

If and when we can agree on that point then we can discuss what effect society has on the matter (excluding the medical effects).

 

[Shippou-Sensei]

even if if there are more people surviving to breed does this not mean that the numbers of subtle variation increase rather than decrese?
even if these variation do not at the moment seriously limit the offsprings chances of reproduction this does not mean that theres is no change
this change is the process of evolution just because at the moment the enviroment is favorable to us does not mean we are in some form of evolutionary stasus

 

[chooch]

Yes we would, however my current point is that it's being slowed by medicine

My point is you can't even begin to weigh all the selection pressures we're under. Selection is blind and subtle, though some of its agents aren't. Just because some of the more obvious pressures are easing on at least some of us there's no reason at all to think selection as a whole is slowing significantly (i.e. that the rate in change of frequency of all alleles is slowing in the whole population). In fact more people means more potential selection events.

And that's ignoring genetic drift.

 

[Bob_the_lost]

even if if there are more people surviving to breed does this not mean that the numbers of subtle variation increase rather than decrese?
even if these variation do not at the moment seriously limit the offsprings chances of reproduction this does not mean that theres is no change
this change is the process of evolution just because at the moment the enviroment is favorable to us does not mean we are in some form of evolutionary stasus

It does (was wondering when the obvious flaw in my arguement was going to turn up ).

However i don't class that as evolution, that's mutation and divergence. Evolution is a combination of those and a process where the "less fit" are out bred or killed off somehow. Everyone breeding equally is not selection. It could be that we're arguing not because we disagree about the facts and science but the language.

I move that this debate be contiuned in pascal.

 

[Shippou-Sensei]

ah but just because the constraining factor isn't visible to us at the moment does not mean that there isn't one of that there won't be onbe in the future

evolution tends to run with species diverting in periods of prosperity only to be refined in times of hardship ... this could easly be part of this cycle

it's a bit of the case of not beeing able to see the wood for the trees

you argument relys on the fact that there isn't now and there never will be an event that humankind can't overcome... because even if we all die out that too is part of evolution

 

[Bob_the_lost]

ah but just because the constraining factor isn't visible to us at the moment does not mean that there isn't one of that there won't be onbe in the future

evolution tends to run with species diverting in periods of prosperity only to be refined in times of hardship ... this could easly be part of this cycle

it's a bit of the case of not beeing able to see the wood for the trees

you argument relys on the fact that there isn't now and there never will be an event that humankind can't overcome... because even if we all die out that too is part of evolution

Evolution is a glacial process, but it is a continual process, it has to be. We're not just talking about the species being wiped out by plauge (although that is one way of it happening), we're also talking about the gradual refinement with the "less fit" being gradually squeezed out.

Right now it's slowed to some extent, the physical aspect is simply not as significant, it's been slowing for quite a while with improving medicine and accses to it. In the near future PGD will start to counteract that, human genetic modification and/or more agressive screening policies will confuse the matter even further. But I am getting offtopic.

If there's a catestrophic dieout in the future then that'll change things again, but for now evolution is not happening (or at least not as quckly as it was even 100 years ago, let alone 1000+). Evolution as a term and a concept is not useful when applied to man in it's current state.

Edited subltly, but i'm not telling you where

 

[Shippou-Sensei]

even if one part of the process is slowed by some factor (in this case infant/juvanile mortality) this does not mean evolution is slowed indeed this is part of evolution

evolution is what you get when offspring are non identical and not all survive to reproduce and that is still the case no matter how good modern medicine and social groups are

 

[Bob_the_lost]

even if one part of the process is slowed by some factor (in this case infant/juvanile mortality) this does not mean evolution is slowed indeed this is part of evolution

evolution is what you get when offspring are non identical and not all survive to reproduce and that is still the case no matter how good modern medicine and social groups are

That's nonsensical.

The process of evolution is being slowed by medicine, thus evolution is going strong?

 

[Shippou-Sensei]

no i just see modern medicine being equivelent to a abundant food source or a particularly oxygen rich atmosphere both of theres things would cause simular dip and bumps in certian species rate of mortality but this does not mean that this is causing evolution to slow

 

[Bob_the_lost]

no i just see modern medicine being equivelent to a abundant food source or a particularly oxygen rich atmosphere both of theres things would cause simular dip and bumps in certian species rate of mortality but this does not mean that this is causing evolution to slow

It's not that simple though is it? An increase in food would not make the slightest difference to someone who's infertile, nor would it aid someone with haemophillia.

Medicine has an effect completely unparralelled in nature. Comparing it to an abundant food supply is misleading.

 

[Shippou-Sensei]

it has a stronger effect it's true but it is still the same concept

not to mention what percentage of the human race actually get medical treatment good enough to overcome infertility or haemophillia

 

[TeeJay]

...we're not dying any less...

Yes we are. The mortality rate, at least in the western world, is far lower than the long term historical average with far more people are living to adulthood: one of the reasons there are about 6 or 7 billion or so humans on the planet now.

 

[fudgefactorfive]

Yes we are. The mortality rate, at least in the western world, is far lower than the long term historical average with far more people are living to adulthood: one of the reasons there are about 6 or 7 billion or so humans on the planet now.

Fair point. I think I was making some kind of half-assed point that 100% of people do die.

Though men do remain viable donors of DNA for most of their life, and medicine apparently makes us live longer (still questionable IMO). And more people are alive, more people are breeding ... that all adds up to more evolution in my book, in the quantitative as well as a qualitative sense.

I can't argue against Bob's position any more than I have already - he thinks evolution means just survival of the fittest, I think it doesn't ...

 

[Azrael23]

Evolution never stops. Life inherently evolves, we`re no different.

The evolution of our conciousness is certainly stepping up a notch, physically change is slow. Shrinking jaws, less hair etc.

 

[fudgefactorfive]

it has a stronger effect it's true but it is still the same concept

not to mention what percentage of the human race actually get medical treatment good enough to overcome infertility or haemophillia

This is what it comes down to really.

The process of evolution doesn't care how the environment came about. In terms of whether we survive long enough to breed or not, evolution doesn't, can't, distinguish between increased rainfall or an aspirin. Medicine is just another part of the environment. Yes, we made it ourselves. But we're far from being the only species that consciously improves its environment, and all those other species haven't ground to a halt.

Meanwhile, look at how medicine is distributed. Not just throughout the world - with its billions below the poverty line - but in a rich country like the UK.

The argument that says letting "weaker" people breed brings about a net loss of genetic evolution, is the argument that gets people put into concentration camps.

 

[Gavin Bl]

Apparently we are evolving tolerance to milk/dairy in adult life - as a result of animal raising - i.e. society.