Humans stop evolving?

[Pyrotex]

Not 100% relevant to the thread, but I can't keep from laughing every time I see this. I shared it somewhere else recently, but if you missed it, check it out. ...

Way too funny. Ought to be illegal. Good catch, IN.

 

Pyro

[freeztar]

Not 100% relevant to the thread, but I can't keep from laughing every time I see this. I shared it somewhere else recently, but if you missed it, check it out. :shrug:

 

:lol:

I saw this post at work initially (no Youtube allowed!). I finally remembered to revisit it tonight. I'm very glad I did. :doh:

 

"He's the dick to the dawk to the phd. He's smarter than you, he's got a science degree. Dick to the dawk to the phd. He's still smarter than you, he studied biology."

 

So true. :hihi:

[Luis]

well, come to think of it, there are so many variants of species for insects, plants, germs that it seems that humanity has reached the end of its evolution; i mean not like its happening now, but i wonder what would it be like...:)

[CraigD]

Hi Luis – welcome to hypography! :evil:

well, come to think of it, there are so many variants of species for insects, plants, germs that it seems that humanity has reached the end of its evolution;

Check out this 12/14/07 Slate article, mentioned in post #24 of this thread.

 

The gist of it – and the mainstream scientific consensus on this thread’s title question, “have humans stopped evolving”, is that quite the opposite of having stopped evolving, humans are evolving more rapidly since we became civilized – the last 40,000, and especially the last 10,000 years – than before. Part of this is simply because there’re more of us, and more individuals = more opportunities for genetic change, but another is that it appears, via civilization, we’re creating more selection pressures than unassisted nature did in the previous 100,000 years, mostly in the for of changed diet and high population density.

i mean not like its happening now, but i wonder what would it be like...:)

It – evolution – doesn’t seem to be happening, because compared to most changes we experience – social, economic, etc. – evolutionary change happens very slowly, requiring at least a generation – about 20 years for humans – for any selection to occur. None the less, research like that described in the Slate article indicated that we’re continuing to evolve.

 

What’s changed very recently – dramatically since about 1960 – is that we’re increasingly able to understand with some amount or exactitude the underlying biology of how we’re evolving – “natural selection” may be even more augmented by “unnatural selection”. Given humankind's propensity and apparent love of change, I find it hard to imagine how this could result in anything but even more dramatic increasing in the rate of evolution, not only in humans, but in all terrestrial ecosystems.

 

In short, the ride, slow-motion one that its been so far, strikes me as far from over, and most likely just getting to the really wild part.

[Michaelangelica]

ShareThis

 

Ala Paredes, Homo Gravis, 2009.

Ala Paredes, Homo Gravis, 2009.

 

Global warming has caused dramatic changes to the earth's surface, air and oceans and the human race has evolved to survive. So what exactly will humans look like when gravity and a habitable earth are things of the past?

 

Last year, design students from the Design Centre Enmore - TAFE were presented with this scenario and came up with a series of designs for future human species that have adapted to survive catastrophic climate change.

 

The startling results - maquettes and works on paper - will be displayed in a new exhibition, Dangerous Worlds, opening on Sunday 30 May, 2010, at the University of Sydney's Macleay Museum.

News | The University of Sydney

[chocochoco]

I think people stop evolving because there is nothing for us to evolve. We are the most perfect section in the world!

[ronthepon]

Interesting topic.

 

Here are my thoughts:

 

Our genetic evolution may have retarded in the sense that genetically superior people are not being strongly selected for in our population by stresses.

 

We could say that this is the result of genetic changes (mental) that have currently suddenly made us the 'fittest'. In our case, the changes were so significant that the carrying capacity of our environment has risen quite a lot. Although this is actually due to technology, information transfer, information repositories, society, etc, etc, etc, but it all still has arisen from our genetic changes that gave us this powerful advantage: brains.

 

That would mean that when we do approach the carrying capacities of our environment, selection will kick back into gear. Annd then, those people would be selected for (on an average), who posess supeior traits for survival in a society overpacked with people. These traits may be primarily behavioural in our case, but the selection will be there.

 

Secondly:

Check out this 12/14/07 Slate article, mentioned in post #24 of this thread.

The evolution of evolution. - By William Saletan - Slate Magazine

As there are more people, and higher tolerances to genetic variation (read genetic defects), during this current phase when there still is a lot of carrying capacity for humans left on this planet, the gene pool of homo sapiens species will accumulate a lot of genetic variability that may be selected when stress comes.

 

So I agree with CraigD: The wild part is going to come.

[Boerseun]

I doubt it. Humans are the most numerous large mammals on Earth, and have effectively removed all geographic barriers that might result in genetic isolation. Whereas other animals evolve due to environmental pressure, with only those capable of surviving the changing circumstances being able to procreate, humans have successfully taken control of their environment and changes the environment to suit them as a species. So far, it's the only species in the History of Life able to do this.

 

Humans born with all sorts of deficiencies are medically panelbeated to such an extent that they can procreate and live a happy and normal life - whilst nothing is done to the cock-up in their genes that caused the problem in the first place. Granted, the cock-up in their genes is also a valid example of evolution, but whereas "normal" evolution amongst non-human animals serves as a mechanism to fine-tune the species to the new, changed environment the species finds itself in, the errors in replication in human genes is merely the continuation of pointless replication errors which serves absolutely no purpose whatsoever - and are not weeded out by selection, either.

 

There are people born today that would not survive for ten minutes outside the Intensive Care ward. Yet, twenty-odd years later you will not see a difference between them and their peers. Until they procreate, and then their kids are terminally dependent on medical assistance from the get-go.

 

I would venture to say that an evolutionary change like the above which will lead to the infant's death if there's no medical assistance available points to a very dangerous deterioration of the human genome. And because humans have destroyed all environmental barriers that might isolate separate groups of humans from each other, these detrimental side-effects of the deteriorating human genome will, generation by generation, end up in making the human species 100% dependent on technology. Say, in a thousand years, technology is deleted from the equation. The human species will die out in one generation, because all the newborns suffer from stacks of hereditary shortcomings that have been carried through generations of humans because the very first kid who suffered from that particular mutation was not allowed to die.

 

I'm not sure if you can call such a degradation "evolution". Evolution is, after all, when different sets of genes are pitted against each other to determine the winner. Amongst humans, everything is let through, and no competition is allowed. Under such circumstances, I suppose you can say that yes, evolution is still happening for people because the genes mix and change with every generation. But I maintain that a generational change where every single imaginable selection sieve is removed is not evolution. The resulting species will be like TV static - sure there's pixels and sound, but the pixels don't make a picture and the sound is just meaningless noise - because everything can go through as a pixel and sound element. The resulting species will be a useless blob of fat with misaligned teeth, heart defects, several organ defects, etc. You get the picture.

 

So I guess if we carry on as we currently are, humans will end up looking however they want - because one of the first pit-stops to be made after birth will have to be with the plastic surgeon, first off to remove all the weird growths on your body, but also to shape you a semi-recognizable face and body - because your ancestors who happened to be born with misshapen bodies through genetic misreplication was fixed up and allowed to carry their genes forward.

 

Eugenics is not the evil it's made out to be! :lol:

[ronthepon]

You're right, provided we define evolution as change for some sort of a 'better'.

 

But as evolution is often defined, it represents the collectively inherited change. In that respect, even if the future populace appears with neoplastic blobs all over the skin, it would be evolution.

 

Further more, in a given condition it may not be clear if a mutation is bad or good. Some mutations like that of sickle cell anemia would be bad in the mainstream society, but it provides for positive selection in malaria prone regions. Lets assume a hypothetical bunch people having a gene giving them poor stamina, but high tolerance to cold.

 

I'd say that evolution has two... 'phases', if you will. One phase is that of variation generation, and the other of selection. In our case, the first phase is a lot more significant than the second, and may remain so for a long time.

 

What I'm saying is that a mutation could be good in some situation. Perhaps it makes the carrier inferior in the current prevailing conditions, but there could arise conditions where the mutation is a major advantage. The population with a lot of genetic diversity has a higher probability of harboring that useful mutation.

 

As to the matter of 'degenerative evolution', that's allowed by the degree of evolution we already have undergone. Because we could get away with carrying forward bad genes, we survive. Our total level of evolution would probably not go back. That would be because even in the future, the good genotypes would still remain in some people, even if the fraction of carriers would reduce.

[Eclogite]

Granted, the cock-up in their genes is also a valid example of evolution, but whereas "normal" evolution amongst non-human animals serves as a mechanism to fine-tune the species to the new, changed environment the species finds itself in, the errors in replication in human genes is merely the continuation of pointless replication errors which serves absolutely no purpose whatsoever - and are not weeded out by selection, either.

You are missing the point. Their genes are perfectly fit for the environment they find themselves in - an environment in which we can take artificial steps to overcome the alleged 'weaknesses'. You know, the same way we invented fire and clothing to overcome the 'weakness' of our lost hair.

Our genome is not weaker, it is simply fit for this environment.

[Boerseun]

You're right, provided we define evolution as change for some sort of a 'better'.

Not necessarily "better". I would say "viable as a living, breathing organism".

You are missing the point. Their genes are perfectly fit for the environment they find themselves in - an environment in which we can take artificial steps to overcome the alleged 'weaknesses'. You know, the same way we invented fire and clothing to overcome the 'weakness' of our lost hair.

Our genome is not weaker, it is simply fit for this environment.

...and I'm probably not bringing my point across clearly.

 

The thing is, amongst humans, the next generation is clearly not determined by the environment any more. The environment, however, is the result of what the human species have made of it. So far, this oddity in evolutionary terms is limited to humans. We have no idea how it would pan out, but it clearly is not evolution in the classical sense. Other species adapt to the environment. With humans, the environment changes according to the species' whims, and have zero input as a selection sieve.

 

The "environment", including the artificial environment as created by humans, where all the medical support and technology forms part of that "environment" (in the classical evolutionary sense) does not fit into the evolutionary idea either, because the current "human environment" is the express effort by humans to remove every single selection sieve imaginable. There is no selection taking place anymore. This is not evolution. This is the propagation of non-viable genes, differentiating in all directions at once. The real test of human evolution can only take place once evolutionary filters are put back in place - oh well, I should probably not post while inebriated. I hope I spelled that right, 'cause I sure as hell can't pronounce it now.

[Buffy]

You are missing the point. Their genes are perfectly fit for the environment they find themselves in - an environment in which we can take artificial steps to overcome the alleged 'weaknesses'. You know, the same way we invented fire and clothing to overcome the 'weakness' of our lost hair.

Our genome is not weaker, it is simply fit for this environment.

:lol:

 

...and moreover, "junk dna" is not junk: it is safely being ignored in the current instance of the object "human" in the current environment. If that ignored sequence were to be made active it could be detrimental to survival in the current environment.

 

But having it *available* to be turned on in some future instance that human's offspring may be essential to that offspring's ability to survive in a *future environment*.

 

That's Evolution! :cheer:

 

Coldest night in 64 years. No place to sleep. All I need now is for it to start snowing. :doh:

Buffy

[Buffy]

The thing is, amongst humans, the next generation is clearly not determined by the environment any more. The environment, however, is the result of what the human species have made of it.

...but I don't think there's anything unusual about *us* being the environment.

 

We weren't around then, but I'll betcha there were places where the dinosaurs basically completely devastated their own habitats because they were so ravenous, leading to evolutionary pressures that caused them to change!

 

Not only are environments not static, the actors have direct effects on them. That includes inventing technology that lets the "weak" survive, which may in fact preserve some dna traces that will in the future be essential to the success of that species because of the diversity of its gene pool!

 

There are 350 varieties of shark, not counting loan and pool, :phones:

Buffy

[ronthepon]

Not necessarily "better". I would say "viable as a living, breathing organism".

I understand the shade of meaning you assign to a 'living, breathing' organism. Yes, our physical bodies may end up -on an average- somewhat inferior to the relatively hardier population of some time back. And that too on a genetical level.

Yes, the selection was more strict in the past. And yes, if a genetically deficient child would be born, it's survival and chances of successful procreation would face difficulties.

 

There is no selection taking place anymore. This is not evolution. This is the propagation of non-viable genes, differentiating in all directions at once. The real test of human evolution can only take place once evolutionary filters are put back in place...

erm... that's a pretty coherent post for an inebriated person... but I digress.

That's the part of your argument with which I disagree. Buffy's post:

...and moreover, "junk dna" is not junk: it is safely being ignored in the current instance of the object "human" in the current environment. If that ignored sequence were to be made active it could be detrimental to survival in the current environment.

 

But having it *available* to be turned on in some future instance that human's offspring may be essential to that offspring's ability to survive in a *future environment*.

...indicates the potential advantage posed by genetic mutation not overtly detrimental, and my previous post (sickle cell anemia) indicates the potential advantages of some of the overtly detrimental mutations.

 

In all directions, the mutations will create more totally 'totally detrimental' traits than 'circumstantially advantageous' traits, but then there still is a small fraction of the latter.

 

Slowed down, evolution has. Stopped, it has not.

[Cephalover]

I am of the opinion that there is very little selective pressure for human evolution. As has been said in this thread, there are few genetic mutations (besides overtly, quickly lethal ones) that render people incapable of reproducing.

 

What I think is need is that this is the sort of "easy period" during which genetic spread can happen - that is, humans can acquire a great variety of mutations during this time of very weak selection. Later on, when there's a sudden environmental change, much of the population can be wiped out, and those few with mutations that allow them to survive better in the new environment will propagate, causing a sort of small leap in human evolutionary development.

 

I think much of the question of whether evolution occurs in humans is semantic. If evolution is the change of genomes due to selective pressure on those genomes, evolution is most likely at a standstill in the human population. If evolution is simply the change of genetic material through mutations (a more general definition than I think is useful), then it is prevalent in the human population, as in all organisms.

[CraigD]

Welcome to hypography, Cephalover! :) I’m impressed with you posts over the last 12 hours – you seem a deeply thoughtful person. :thumbs_up

I am of the opinion that there is very little selective pressure for human evolution. ...

Until reading a few articles linked from this thread about 25 months ago, I was of a similar opinion. Quoting myself to save time:

Check out this 12/14/07 Slate article, mentioned in post #24 of this thread.

 

The gist of it – and the mainstream scientific consensus on this thread’s title question, “have humans stopped evolving”, is that quite the opposite of having stopped evolving, humans are evolving more rapidly since we became civilized – the last 40,000, and especially the last 10,000 years – than before. Part of this is simply because there’re more of us, and more individuals = more opportunities for genetic change, but another is that it appears, via civilization, we’re creating more selection pressures than unassisted nature did in the previous 100,000 years, mostly in the form of changed diet and high population density.

...

Since then, my perception and opinions on the subject have been strongly shaped by the conclusions expressed in this and similar articles (at their core seems to be a study by Utah U’s Henry Harpending, which, unfortunately, I’ve not yet read). I find anecdotal evidence all around me that, rather than reducing selective pressure, human civilization is increasingly increasing it.

 

Consider very recent – the last 25 years in the US, less than 10 in many emerging economy states – changes in much of the population’s diet, and the linked increase in obesity and diet-related conditions such as diabetes, due changes in the marketing and economics of food. IMHO, these approach or may even exceed the impact of changes in diet due to the emergence of agriculture and domesticating milk animals that Harpending describes as having so profoundly affected human evolution beginning 40 to 10 thousand years ago. It takes no great stretch of imagination to credit that many people born into this “new environment” may reproduce or not depending on their fitness or lack of fitness in it. For example, many type 2 diabetic and morbidly obese (60% above normal weight) children may not successfully reproduce.

[Rade]

See this web site:

The Future of Human Evolution Website | HumansFuture.org

 

There is no reason to suggest that human evolution has stopped, nor that humans will not continue to evolve. In fact, recent DNA evidence indicates that mutation rates are increasing in humans (for reasons such as increased exposure to chemicals in our air, land and water), resulting in random changes in gene frequencies. As these random genetic changes become isolated due to cultural differences, or economics, or religion, etc. then they will no longer be random, and by definition natural selection (a type of micro-evolution) is the non-random reproduction of genotypes. Note what is happening in Europe and Russia, more and more small countries based on ethnic history and religion being formed--each event results in a greater frequency of genetic isolation. In America, political and religious and racial trends are forming greater isolation in recent times--our melting pot appears to be cooling and small groups becoming more isolated--an important requirement for future non-random changes in gene frequencies in populations.

 

I think there is a high probability that our species will form new species in the far future, the first logical mechanism will be as we begin to colonize other planets. All that is needed is reproductive isolation. Via genetic engineering and nanotechnology there is absolutely no reason to think that some group of future humans, perhaps united by a philosophy or religion, would not form a society that would isolate itself reproductively from other human population--when that event occurs a new species will be born. A simple change in how the sperm cell fertilizes an egg would do. Ironically, such a group might hold as a basic premise that they were created by a God.