arthwollipot
Observer of Phenomena, Pronouns: he/him
Human Evolution Has Stopped
- Thread starter arthwollipot
- Start date
It's a Fukuyama moment. He's simply making the assumption that the conditions we have observed for the last 100 years will be the same for the next million. And, inevitably, the illustration is the usual incorrect cliche. When is someone going to redraw it with erect posturte preceding brain development?
El Greco
Summer worshipper
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Of course it has stopped, there's is no isolation any more and man is becoming more and more skillful at genetic engineering. As long as things remain that way there will be no further natural-selection-based evolution. Of course in 253,601 years a comet may hit Earth and isolation may occur again.
SezMe
post-pre-born
Human evolution has not stopped. However, evolution by natural selection is no longer the dominant driving force.
arthwollipot
Observer of Phenomena, Pronouns: he/him
What is?
Mojo
Mostly harmless
Cainkane1
Philosopher
Its been slowed down but it hasn't stopped. I've know married couples with inherited genetic problems that have volutarily not had children because of the possibility that their children would have the same problem. I've known parents with children who were afflicted with Downs syndrom who had their children sterilized. This of course takes some people out of the gene pool.
You're right, but even if that assumption was correct, it would still not imply that there is are no selection pressures--at most, merely the same ones.
In terms of the theory of evolution, the distinction between "natural" and "man-made" factors is spurious. Humanity is still a part of nature; all it this means is that we've now more influence over our environment, and hence selection, than we did in the past. Perhaps we can say that we've more (indirect) control over our own evolution, but not that our evolution has stopped.
Aepervius
Non credunt, semper verificare
I assume he thinks that evolution stopped because we can "palliate" to change in our environment and our reproduction is weakly linked to the most successful at bringing living offspring to reproductive age, again palliative medicine helps offspring which would have died before. So society seems to be erasing the advantage evolution would bring, no pressure on gene, means all mutation are about as disadvantageous as advantageous => no evolution.
Considering the world as a whole, you can see a lot of place on earth where there are not enough resource to fight against environmental factors, and thus some genetic profile make off better than other.
But even in the west world, I disagree on this, as we can only palliate to a degree. If really the environment would go out of norm (too hot/too cold), our society would be limited in how far the environment influence can be reduced, and some genetic profile would be advantaged over other (imagine for example the ozone get thinner and more UV comes in, no matter the world resource people with different melanine composition could lose more offspring before reproductive age due to skin cancer).
But if the whole world become a sort of "western" world with a lot of palliative medicine, then the lack of environmental pressure or intern pressure would make all offspring chance to come to reproduction equal, and thus no advantage/disadvantage to a particular gene pool would be given.
Considering the world as a whole, you can see a lot of place on earth where there are not enough resource to fight against environmental factors, and thus some genetic profile make off better than other.
But even in the west world, I disagree on this, as we can only palliate to a degree. If really the environment would go out of norm (too hot/too cold), our society would be limited in how far the environment influence can be reduced, and some genetic profile would be advantaged over other (imagine for example the ozone get thinner and more UV comes in, no matter the world resource people with different melanine composition could lose more offspring before reproductive age due to skin cancer).
But if the whole world become a sort of "western" world with a lot of palliative medicine, then the lack of environmental pressure or intern pressure would make all offspring chance to come to reproduction equal, and thus no advantage/disadvantage to a particular gene pool would be given.
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Readily available birth control has only been with the species for a few decades--a blink of an eye in terms of selection. Sex for pleasure is now partially independent from sex for reproduction. I can think of a few possible evolutionary results... depending on what things are or are not genetically determined.
Dancing David
Penultimate Amazing
Silly, people still die from bacterial and viral infections. Some people don't know what natural selection is.
Dancing David
Penultimate Amazing
Hmm, before I critique this interesting meme, how about you explain how it works? That way I am critique what you think and not this comment.
Natural selection is the passing on of traits through reproductive success.
Natural selection at the replicator level is differential reproductive success of replicators. A meme that encourages ethnic cleansing encourages its carriers to disadvantage rival replicators, giving the carrier the opportunity to (differentially) replicate BOTH meme and genes.
You've got to distinguish what is replicating. For example, the elimination of the ethnic cleansing meme may still leave the gene with an advantage.
Memes
Ordinarily, as I have seen them, memes are brought up in terms of their own evolution - the evolution of ideas. That is, conceptually, a meme is a non-physical entity, a concept, thought, idea, image, etc, that evolves over time (though generally, this evolution is Lamarckian rather than Darwinian - ideas do not generally have a distinction between a germ-line and soma).
There is a problem of scale with memes, as it is not generally very easy to determine whether or where to draw a line between an individual meme, and a complex of memes, or meme-organism. Still, a variety of real-world examples of memes have been proposed - from the very simple and small, such as infectious tunes that linger in the mind, to the large and indefinitely prolonged, such as religion.
Ethnic cleansing, religious-motivated genocide, and even the lesser example of racial violence, are potential examples of a meme (or memetic group) causing a differential reproductive survival amongst those impacted by them.
Ethnic violence is obvious, and where religions are closely tied to ethnicity, a similar degree of obviousness occurs.
More subtle examples of the influence of memes is seen in sexual selection in organisms that display communication of ideals. That is to say, simple sexual selection, such as the ratchet effect on bird feather length, is not easily shown to be memetic, and likely is not. However, where sexual preference *changes* within a single generation or portion of a generation, or more specifically, where individuals are observed to change their preference during their lifetime, such as the rapid decline in the reproductive success of males sporting mullets in the U.S.
On a different note, I would point out that the idea that palliative care could be responsible for a cessation of evolution basically drops 'differential reproductive success' in favor of 'differential survival'... which is possibly applicable in terms of bacteria, as long as they aren't exchanging DNA or RNA, but not very applicable to humans.
Even if our likelihood of survival was completely evened out, such that every person that was conceived was also born and grew to the same age before dying, that would not remove the element of reproductive success. And of course, our likelihood of survival is NOT even.
Can we conceive of a world where both elements were evened out? It is possible - in a dystopian future such as seen in the Matrix, where humans are grown and harvested, it might be possible to basically provide equal life expectancy and probability of reproduction across all of humanity. Would this stop evolution? Not really - if the reproduction was essentially random, where any given individual is equally likely to reproduce with any other individual of the opposite sex, then humanity would evolve towards a homogenization of form, though this would necessarily have limits, due to the nature of Mendelian genetics. If the reproduction was non-random, then essentially we would be in a situation of guided evolution, much as we breed dogs.
So has human evolution stopped? No, not at all. Realistically, human evolution will cease when humanity ceases. Extinction, if and when that strikes humanity, is the only thing that would really stop evolution.
Howard, The Grum
Ordinarily, as I have seen them, memes are brought up in terms of their own evolution - the evolution of ideas. That is, conceptually, a meme is a non-physical entity, a concept, thought, idea, image, etc, that evolves over time (though generally, this evolution is Lamarckian rather than Darwinian - ideas do not generally have a distinction between a germ-line and soma).
There is a problem of scale with memes, as it is not generally very easy to determine whether or where to draw a line between an individual meme, and a complex of memes, or meme-organism. Still, a variety of real-world examples of memes have been proposed - from the very simple and small, such as infectious tunes that linger in the mind, to the large and indefinitely prolonged, such as religion.
Ethnic cleansing, religious-motivated genocide, and even the lesser example of racial violence, are potential examples of a meme (or memetic group) causing a differential reproductive survival amongst those impacted by them.
Ethnic violence is obvious, and where religions are closely tied to ethnicity, a similar degree of obviousness occurs.
More subtle examples of the influence of memes is seen in sexual selection in organisms that display communication of ideals. That is to say, simple sexual selection, such as the ratchet effect on bird feather length, is not easily shown to be memetic, and likely is not. However, where sexual preference *changes* within a single generation or portion of a generation, or more specifically, where individuals are observed to change their preference during their lifetime, such as the rapid decline in the reproductive success of males sporting mullets in the U.S.
On a different note, I would point out that the idea that palliative care could be responsible for a cessation of evolution basically drops 'differential reproductive success' in favor of 'differential survival'... which is possibly applicable in terms of bacteria, as long as they aren't exchanging DNA or RNA, but not very applicable to humans.
Even if our likelihood of survival was completely evened out, such that every person that was conceived was also born and grew to the same age before dying, that would not remove the element of reproductive success. And of course, our likelihood of survival is NOT even.
Can we conceive of a world where both elements were evened out? It is possible - in a dystopian future such as seen in the Matrix, where humans are grown and harvested, it might be possible to basically provide equal life expectancy and probability of reproduction across all of humanity. Would this stop evolution? Not really - if the reproduction was essentially random, where any given individual is equally likely to reproduce with any other individual of the opposite sex, then humanity would evolve towards a homogenization of form, though this would necessarily have limits, due to the nature of Mendelian genetics. If the reproduction was non-random, then essentially we would be in a situation of guided evolution, much as we breed dogs.
So has human evolution stopped? No, not at all. Realistically, human evolution will cease when humanity ceases. Extinction, if and when that strikes humanity, is the only thing that would really stop evolution.
Howard, The Grum
paximperium
Penultimate Amazing
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That was very well said. I have nothing to add or disagree with it...I hate not being able to argue.
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erlando
Master Poster
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- Apr 23, 2007
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- 2,432
Susan Blackmore gave a very interesting TED-talk "Memes and temes" about what may take over as the driving force of human "evolution" (of course not on a genetic level as such):
http://www.ted.com/index.php/talks/view/id/269
http://www.ted.com/index.php/talks/view/id/269
Aren't 'very interesting' and 'TED-talk' redundant? Or perhaps I mean synonymous. I suppose there is probably a boring one out there . . . but I haven't found it yet.
Howard, the Grum