Is the Human Race still evolving?
- Thread starter Nickster
- Start date
Bob_the_lost
Elsewhere
Increase the food supply and you decrese competition, more cubs from the litter will survive to breed in turn. However when the limit to the food source is reached the competition for food is greater and as such more will die off before breeding.
That's not what is happening now is it? As countries/regions enter the 4/5th stage on the demographic transisition model you see the birth rate and death rate level off, population becomes roughly static. The birth rate and death rate level off, not because more infants are dying, but because less are being born. The competition is irrelevant.
If evolution is happening in man it's so utterly divorced from that in animals it's not worth the effort to compare them.
And as a final point for this post:
Wrong. Sharks and crocodiles(or is it alligators
) for example haven't evolved for a long long time. Mostly because they are almost perfect for their task. Evolution can stop even while selection is high if the situation is right.
Note: At no point have i accused you or anyone else of being a Boer, nor would i even put the dutchies in a concerntration camp now. Perhaps what you're thinking about is eugenics, passive (as we practice to some extent today) or active (sterilisation as done by governments and people beyond counting). Just because i say evolution has stopped it does not mean that it should be started again in some manner, in other words enough of this "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."
That's not what is happening now is it? As countries/regions enter the 4/5th stage on the demographic transisition model you see the birth rate and death rate level off, population becomes roughly static. The birth rate and death rate level off, not because more infants are dying, but because less are being born. The competition is irrelevant.
If evolution is happening in man it's so utterly divorced from that in animals it's not worth the effort to compare them.
And as a final point for this post:
chooch said:
Wrong. Sharks and crocodiles(or is it alligators
) for example haven't evolved for a long long time. Mostly because they are almost perfect for their task. Evolution can stop even while selection is high if the situation is right.Note: At no point have i accused you or anyone else of being a Boer, nor would i even put the dutchies in a concerntration camp now. Perhaps what you're thinking about is eugenics, passive (as we practice to some extent today) or active (sterilisation as done by governments and people beyond counting). Just because i say evolution has stopped it does not mean that it should be started again in some manner, in other words enough of this "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."
Shippou-Sensei
4:1:2.5
the first part of your argument could be applied to humans as well curently there is a boom but this may well cause competition in the future you could even claim it is alredy doing so due to the state of some third world countries
and no sharks and crocodiles have not stopped evolving of even slowed they are evolving but the deign stays roughly the same just as the Ichthyosaur strongly resembles the modern dolphin some designs are just right for the enviroment and just because a design doesn't change does not mean evolution has stoped ... take the cockroach for example the cockroach is 354–295 million years old but the design is almost identical to modern ones but the genetic make up is probably vastly diffrent
as i repeat evolution occurs when non identical offspring occur and not all offspring reproduce ... this is still the case today to say that sharks have stopped evolving is totally wrong continuoulsly breadding but remaining the same is also evolution
and no sharks and crocodiles have not stopped evolving of even slowed they are evolving but the deign stays roughly the same just as the Ichthyosaur strongly resembles the modern dolphin some designs are just right for the enviroment and just because a design doesn't change does not mean evolution has stoped ... take the cockroach for example the cockroach is 354–295 million years old but the design is almost identical to modern ones but the genetic make up is probably vastly diffrent
as i repeat evolution occurs when non identical offspring occur and not all offspring reproduce ... this is still the case today to say that sharks have stopped evolving is totally wrong continuoulsly breadding but remaining the same is also evolution
Bob_the_lost
Elsewhere
So this boom is occuring despite the lack of population growth? Thrid world countries are merely further behind on the demographic transition model, given time they too will do the same. The competition is not there.Shippou-Chan said:
Constantly breeding but remaining the same is in no way evolution, evolution is defined as the change. As i remember i was the one who was hammering that definition of evolution home, are you accepting that since a far far greater percentage of humans are making it to breeding age that evolution is slowed now?
Talking about a boom/bust situation in the future is a waste of time. It may happen, but elvis may return from space with his alien buddies. All we can do is examine the past and present, from which it's clear that humanity is not evolving as fast if at all.
Wrong in that lesser used sense of 'utterly right'?Bob_the_lost said:
Of course sharks and crocodiles are evolving- their environment is changing all the time- but some of the genetic changes (e.g. changes in disease resistance) happening right now may not be very visible to you or me.
Shippou-Sensei
4:1:2.5
constantly breading but remaining the same is evolution because offspring are non identical if all offspring survied the species would slowly become further and further apart as it hapens most of the offspring that deveate from the norm die off therefore the species stays the same .... that is evoloving to stay the same
and evolutioin is not the change! the change is part of the process (one possible out come) but not the process itself
also you were the one who brought in the boom/bust situation when i pointed out medicine was like a food supply ... if we ignore the future favorible weather and food production across the world would also "slow evolution" a concept that is simply wrong
and evolutioin is not the change! the change is part of the process (one possible out come) but not the process itself
also you were the one who brought in the boom/bust situation when i pointed out medicine was like a food supply ... if we ignore the future favorible weather and food production across the world would also "slow evolution" a concept that is simply wrong
free spirit
more tea vicar?
Nickster said:
in short ... NO
in fact contrary to Bob's slightly skewed assertions on this thread the uman race must logically be evolving faster now than at any time in history due to the follosing factors...
a. there are almost as many people alive today as have ever lived in the history of the human race... the more people there are breeding, the more changes there are going on, the faster the rate of evolution.
b. there is way more interbreeding between races going on today than ever before, so genepools that have developed in virtual isolation for thousands of years are suddenly mixing with each other... evolution. It is true that a lot of evolution from one species into 2 or more different species has happened over time through issolation of the different evolutionary strands, such as those on different islands, but when people who've been isolated from each other evolutionarily for thousands of years begin interbreeding again (eg. scadinavians with aboriginis) this too has an evolutionary affect on the genepool.
c. There are a wide range of diseases and natural disaters frequently (or constantly) sweeping vast swathes of the planet, wiping out those most vulnerable to the different diseases / drought / famine etc. HIV / AIDS 9for example) could well have a massive impact on the overall genetic makeup of the human race, firstly if there is any genetic immunity among certain groups then these groups would naturally take over where genetic groups more predisposed to contracting HIV/AIDS are virtually wiped out [AFAIK the juries still out on genetic immunity, but this is an illustrative example] secondly the genepool of areas of the world that took action before HIV got to epidemic proportions is likely to survive much more intact than that of areas that allowed it to get to full epidemic proportions.
There are also something like 2 billion people living under the poverty line, with infant mortality rates at similar or worse rates than those of much of human history, so to say that modern medicine has taken this impact out of evoultion shows a very westernised outlook on the world... 2 billion people is more than the entire global population uptil around 1930-1940, and survival of the fittest style evolution is very much alive and kicking among these 2 billion people who's survival strategy generally revolves around having enough children to ensure at least a couple of them survive to adulthood.
OK so AFAIK we're not about to have loads of wierd mutations meaning there's different subbreeds that can fly, shoot lasers from their eyes, breath under water etc. etc. but that's comic book bollocks. Other than that, I can't see any valid arguement for human evolution slowing down just yet.
Bob_the_lost
Elsewhere
a) More alive, not more being born. Infant mortality (worldwide) has fallen massively since 1960 let alone since yee olde days. As seen earlier in this thread:
b) A point, but see above.
c) Balls. Which diseases are these? What disasters are you refering to that occur so often? Famine is an odd one, i've seen the data on the Bangladesh famines, where the population increased yearly. More selection yes, but not universal.
Poverty line? This'd be the same poverty line that says anyone who doesn't have a TV is under it? Also you're just wrong about the infant mortality rates, angola had the highest as of 2005 with 187.5/1000, which was the world average as recently as 1960. If you're arguing that this is a sign that selection is still occuring then you'll have to do better. The population isn't increasing because more children are being born. It's because less of those born are dying young.
Again we're back to selection.
b) A point, but see above.
c) Balls. Which diseases are these? What disasters are you refering to that occur so often? Famine is an odd one, i've seen the data on the Bangladesh famines, where the population increased yearly. More selection yes, but not universal.
Poverty line? This'd be the same poverty line that says anyone who doesn't have a TV is under it? Also you're just wrong about the infant mortality rates, angola had the highest as of 2005 with 187.5/1000, which was the world average as recently as 1960. If you're arguing that this is a sign that selection is still occuring then you'll have to do better. The population isn't increasing because more children are being born. It's because less of those born are dying young.
Theoretically evolution consists of two parts:free spirit said:
Random mutations (increases genetic diversity).
Natural selection (ecological and sexual) giving differential mortality - ie in the survival rate of individuals to their reproductive age.
The first of these increases genetic diversity, while the second decreses it - ie "speciation" and "extinction".
The fact that there are more humans about now does not *by itself* mean that the 'rate' of evolution is any faster or slower.
Strictly speaking evolution is "the measurable change in the heritable traits (allele frequency) of a population over successive generations" - but in fact this is not that easily quantifiable without drawing up a complete Genome, something that has been done for only some species/individuals and of course much of the current theory and thinking about evolution comes from studying the fossil record - which for most of there is no DNA available.
I would recommend anyone/everyone on this thread have a read through the wikipedia article on all this: http://en.wikipedia.org/wiki/Evolution
The disputed point isn't that there are two million living in "poverty" - it is that for most of human history most people were far worse off than they are now.chooch said:
freespirit claims that: "There are also something like 2 billion people living under the poverty line, with infant mortality rates at similar or worse rates than those of much of human history, so to say that modern medicine has taken this impact out of evoultion shows a very westernised outlook on the world..."
You will find that this doesn't correspond to the actual evidence. Child mortality rates throughout much of human history have been far higher than they are now for the quoted "2 billion people".
If necessary I will go and find the figures to back this up, but it is not a controversial fact and very easily checked if anyone wants to spend a bit of time Googling for it.
The disputed point is whether that (to my mind indisputable) fact would have anything to do with the 'rate of evolution', which extending your good definition would be the 'rate of the measurable change in the heritable traits (allele frequency) of a population over successive generations'.TeeJay said:
Bob_the_lost
Elsewhere
I'm not getting your point here. To have the ratios of alleles change you need some people to die and some to breed, or some to breed more than others. That's effectivly what your definition says. Just checking we're on the same page here.chooch said:
In an MEDC you're looking at a roughly 1:1 ratio. Nearly all children born survive to reproduce themselves. That's not evolution by your own definition as the ratio of various alleles is unchanged. Of course that's an approximation, some children do die, some people chose to breed less which will change the ratio of alleles in the population. That would be a good point if it didn't occur in nature too. As such you've got factor X which is unchanged and Y which has been halved in the last 40 years alone.
In LEDCs the rate of infant mortality is at worst the same as the global average in the 1960s. Look at the numbers and you'll see them decreasing year on year (with the inevitable peaks/troughs). In LEDCs you're looking at the same effect as MEDCs but to a lesser extent. They are just a stage or two behind on the demographic transition model.
You're arguing for something that is utterly unsupported by science, logic and your own definitions. Why?
No. You need some people to breed. Ignoring new alleles from mutations, genetic drift would do it even with a constant rate of death and reproduction.Bob_the_lost said:
However we're talking about selection pressures (i.e. factors, including early death, that for some reason lead to more offspring for carriers of one allele over another allele). You're arguing that since fewer of us worldwide are dying from diseases of crushing poverty before getting to the age where we can have children therefore there are far fewer selective effects. I'm arguing that this unarguable reduction in childhood mortality means we're now open to a host of new selection pressures which were previously masked by a good chunk of us dying too young to breed (for reasons that have nothing to do with genetic makeup other than the extent to which people born, by historical accident, to crushing poverty tend to share genes).
If, by compulsory genetic testing, perfect medicine and the application of a faultless and everlasting dictatorial welfare state, carriers of every possible allele were supported to child bearing age and forced to have equal numbers of offspring then we'd have no effective selective pressures. But genetic drift would be still be changing the relative frequency of alleles in the breeding age population because (ignoring maternal mitochondrial DNA) we only pass on half of what we have and it happens by chance. So we'd still be evolving.
However, this isn't the case, nor is there any sign of it being the case. Genetic susceptibility to croaking because of a lack of clean water or food still affects a good chunk of the population, other kinds of genetic susceptibility to early croaking still affect the rest of us, other kinds of genetic susceptibility to reduced reproductive success still affect all of us, sexual selection still applies, people still can't have children, or choose not to. So we're still evolving.
So we're either still evolving or still evolving.
I'm arguing for something that seems relatively obvious to me. Hopefully without being a pompous twat.
Bob_the_lost
Elsewhere
chooch said:
A situation that can and does influence evolution, that is no longer (as) relevant to humanity because of the much larger population and interbreeding, a supporting point for my arugment not yours.
Ok, so we are still under "survival of the fitest" criteria in terms of physical effects. No arguement there, but in turn it's obvious that this is less than it's ever been in history and that the current trend is for it to fall even further.chooch said:
Ok, prove it. For these new selection pressures to be significant you'd have to show that there was a larger fraction of the world population not breeding now than it was in the past.
I'll restate my position clearly; physical selection is less of a factor than it has ever been in the past. Without any evidence or even convincing theories to show that societal selection is greater than it has been then it is unfair to claim that total selection has remained unchanged. Diversification without selection is not evolution. As such diversification with less selection can be described as less evolution. If i said that evolution was stopped then it was laziness, it's slowed not stopped completely (although the difference between a process that's almost geological in it's pace and one that's frozen completely is rather academic).
As an aside if i've been rude (probable) i appologise, this thread has been interesting and i'd hate to contribute to turning it into a flame fest.
It's still relevant. It applies to all population sizes, just more obviously to small populations with no interbreeding. In a larger population it would take proportionally at least as much interbreeding for genetic drift to be unimportant. Any evidence of that?Bob_the_lost said:
As noted, in a larger population you'd also have more mutation events- new alleles, and, because of this, susceptibilities to a wider range of selection pressures.
For one (obvious) type of selection pressure. But not for all other types of selection pressure.
Can't. No real statistical evidence. None for your position either. Though there might be in a generation or two.
I'm not sure it can. To use the wikipedia definition, evolution is the measurable change in the heritable traits (allele frequency) of a population over successive generations. Diversification (from a bigger population leading to numerically more mutations and therefore new alleles) would lead to change in the allele frequency of a population over successive generations, so diversification is evolution.
You're trying to identify the rate of selection. That's not possible because you can't identify all selection pressures and number of people getting through childhood and maybe having the chance of breeding isn't an analog for it. What you maybe can identify (with enough handy genome testing kits and a couple of hundred years) is rate of change of particular alleles or rate of change of the whole genome. A control Earth with a carefully controlled rate of sudden child mortality and miserably unnecessary death would allow us tocompare and contrast.
That's an interesting point. To my eyes evolution can be very quick- particularly for those unencumbered with big bodies and longish lifespans. Human evolution looks slow because we think, unsurprisingly, that a generation or two is a long time.
Sorry if I've done the same. Good thread.
Bob_the_lost
Elsewhere
It's a statistical factor, think of it as a variant of gambler's ruin. You play the odds long enough then you lose because the bank can survive the long losing streaks except here both you and the bank can run out of money. If you've only got £10 and playing £1 a time then you're going to hit the losing streak quicker than if you've got £1,000 and playing £1 a time. The same effect exists for genetic drift.chooch said:
It's still less relevant than it used to be. See the wiki article on it for backup.
Ah but there is evidence for the lack of physical selection, see the birthrates. One way to compare the rates of people not breeding would be to look at the domesday book and compare the number of married couples with children, singletons and married childless couples. If a similar fraction of people at the moment are childless it'd show that there are no greater societal forces at work than at that time (of course you'll have the issue of physical selection, but while there was a fraction of the populance who's children all died at a young age it wasn't the majority, and we're only looking for those who tried for children, not those that sucseeded.chooch said:For one (obvious) type of selection pressure. But not for all other types of selection pressure.
Can't. No real statistical evidence. None for your position either. Though there might be in a generation or two.
I don't have to identify them all (que smug grin
), all i have to do is to show that at least one factor is less now and that the others are unchanged. Physical selection (in terms of survival) is lesser and i'm yet to see anything to suggest that current society is more selective than it used to be.Example: Woman too evil and nasty to find husband, finds online sperm donor. (Yes it's a crap example). Weak/Constantly ill bloke finds woman who can see the inner goodness (as opposed to being the last choice in ye olde caveman days).
free spirit
more tea vicar?
TeeJay said:
ok you're probably right for the 2 billion figure, as this is an approx figure for those who're poor as opposed to the 1.1 billion in absolute poverty or the 790 million people in the developing world are still chronically undernourished... the point I was trying to make [badly] was that infant mortality rates for countries are given as the average for that country yet if you took the infant mortality rate for only the poorest x hundreds of millions globally you'd probably find it wasn't actually that much different to the average global mortality rate in 1930 when the entire global population was 2 billion... personally I'd be surprised if it wasn't around the same for the 2 billion figure I quoted but seeing as the figures either aren't being collated or are not easily accessible I can't really prove / disprove this hypothesis.
"at similar or worse rates than those of much of human history" I'll admit to being wrong with this bit though... went off on one there
free spirit
more tea vicar?
Bob_the_lost said:
ok there are currently 2.2 billion children in the world, a figure that is equal to the entire world population circa 1930. 1.9 billion of them live in the developing world where the number of children born per woman are generally between 3-7 average. Yes the overall birthrate is declining globally, but there's way more people out there to have kids, so the actual number of actual children being born globally has to be greater now than at virtually any point in history.
HIV/aids, tb, malaria etc.
HIV/aids for example in subsaharn africa 6.1% of the adult population is infected with HIV, with 2 million dieing from it last year - this level is climbing rapidly, and who knows how high it could be in 20 years time.
Selection pressures don't have to be universal to have an impact on the genepool on a local / regional level, actually if they were universally applied would they have any real effect at all? - if they affected all gene types equally there'd be no real change in the overall genepool ratios, whereas if a disease affects certain genetypes more than others then those genetypes affected will become less prevalent within the genepool than those genetypes that were less affected. This can be due to either genetic, social, environmental or geographic disposition to the disease... ah shit my head hurts it's late and I wish i'd not got into this debate, interesting stuff though
It'd show that a similar fraction of people at the moment are childless. It'd tell us nothing about any past or present selection pressures except those, unidentifiable in intensity without much more knowledge, relating to susceptibility to all those nasties we rich folk don't worry about now. It'd tell us nothing about the rate of change of frequency of alleles without knowing things like distributions of numbers of offspring, distribution of parents' ages at birth of each child and distribution of ages of offspring (to give us generation lengths) and pre-existing allele frequencies. Unless we know everything (as in the state controlled breeding example) we know very little, averages being what they are.Bob_the_lost said:
Which you can't do (cue smugger grin with a even more pronounced wink). Your point would, I think, hold if all selection pressures were tidily independent, but they're not. Some selective effects are partly dependent on, for example, a good proportion of us not croaking, through no particular genetic cause, in early childhood (e.g. susceptibility to cancers of late childhood of complex cause, sexual selection in a rich world where most people have good teeth).I don't have to identify them all (que smug grin
These sentences are too long. I'm drunk. And Brazil were awful.
Jonti
what the dormouse said
Fair enough. Spot on, even.Bob_the_lost said:
But, one thinks of evolution as a slow process over time, as diversification along with continual selection. Presently, we have the same old rate of diversification, but decreasing selection. So people will want to say we are still evolving, just because it seems misleading to talk as if a mass selection event would be the moment evolution occurred.
Instead of the human race following one evolutionary path, it is following many, so to speak, while remaining an interbreeding population.
Shippou-Sensei
4:1:2.5
i still hold that as long as offspring are non identical and not all ofspring survive to breed evolution continues
argument about any particular area (such as birth rate or medical progress) misses the larger picture
argument about any particular area (such as birth rate or medical progress) misses the larger picture
scifisam
deleted
Apologies for entering the thread so late. It's a topic I've thought about before too.
Well, they're still examples of survival of the fittest, really. That term - 'survival of the fittest' - is apt to confuse all of us. All it means it that those who fit best it the world will reproduce; it has nothing to do with physical abilities, health or genetic suitability. If a woman can afford to raise a baby on her own after finding an online sperm donor (btw, I'm pleased that nobody chose to take your devil's advocate examples the wrong way), then she is fit for the world she lives in. If an ill man can still find a woman who wants to have kids with him, then, one way or another, he is genetically fit for the world he lives in.
Evolution isn't an upward spiral to a better species. It's just changing to fit the environment. In most of the world these days, physical ability is not as important as intellectual ability. Thus we are changing, slowly, in the sense that there are far more physically 'unsuitable' people reproducing now because they're intellectually suitable.
There's also the accelerated rate of migration around the world. That cannot be discounted when considering evolution. The Western world may no longer be excluding people from reproduction because of their physical infirmaties, but it is now including people from a much wider genetic background.
I think I know where you're coming from, though. Were any of the previous varities of hominids capable of thinking that 'we are the end product' in the same way that homo sapiens does? I'm not sure they were. They sure weren't capable of controlling it. We certainly are, however, and I bet that (barring worldwide disasters) we wouldn't let our descendants change into something noticeably different to the way we are now.
Evolution is still happening, but slowly - it's just an adjustment; I don't think that there will ever be another homo [whatever] after homo sapiens.
Bob_the_lost said:
Well, they're still examples of survival of the fittest, really. That term - 'survival of the fittest' - is apt to confuse all of us. All it means it that those who fit best it the world will reproduce; it has nothing to do with physical abilities, health or genetic suitability. If a woman can afford to raise a baby on her own after finding an online sperm donor (btw, I'm pleased that nobody chose to take your devil's advocate examples the wrong way
), then she is fit for the world she lives in. If an ill man can still find a woman who wants to have kids with him, then, one way or another, he is genetically fit for the world he lives in. Evolution isn't an upward spiral to a better species. It's just changing to fit the environment. In most of the world these days, physical ability is not as important as intellectual ability. Thus we are changing, slowly, in the sense that there are far more physically 'unsuitable' people reproducing now because they're intellectually suitable.
There's also the accelerated rate of migration around the world. That cannot be discounted when considering evolution. The Western world may no longer be excluding people from reproduction because of their physical infirmaties, but it is now including people from a much wider genetic background.
I think I know where you're coming from, though. Were any of the previous varities of hominids capable of thinking that 'we are the end product' in the same way that homo sapiens does? I'm not sure they were. They sure weren't capable of controlling it. We certainly are, however, and I bet that (barring worldwide disasters) we wouldn't let our descendants change into something noticeably different to the way we are now.
Evolution is still happening, but slowly - it's just an adjustment; I don't think that there will ever be another homo [whatever] after homo sapiens.
Shameless thread resuscitation.
Culture Speeds Up Human Evolution
Culture Speeds Up Human Evolution
Jonti
what the dormouse said
More about this from the BBC ...
weltweit
Well-Known Member
Is the human race still evolving?
Of course it is, why would it have stopped?
It would only have stopped evolving if it had reached perfection for the state of the environment in which it lives. Humans across the globe live in a wide variety of environments today and it is reasonable to argue IMO that in each of these environments some level of different evolution is taking place.
Of course it is, why would it have stopped?
It would only have stopped evolving if it had reached perfection for the state of the environment in which it lives. Humans across the globe live in a wide variety of environments today and it is reasonable to argue IMO that in each of these environments some level of different evolution is taking place.
merlin wood
mind traveller 3rd class
Although one can think that the human species would need to evolve quickly and in a radical way to avoid reverting to a new dark age that could result from global warming.
is the human race still evolving
Well, no I reckon we're just drifting at the moment.
We'll have a good load of selection if civilisation's wiped out though, and ironically, it'll probably, and hopefully be people who've invested in friendship who'll be more likely to survive than people who've invested in ownership.
Well, no I reckon we're just drifting at the moment.
We'll have a good load of selection if civilisation's wiped out though, and ironically, it'll probably, and hopefully be people who've invested in friendship who'll be more likely to survive than people who've invested in ownership.
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