Human Evolution Enters an Exciting New Phase
wired.com
wired.com
If "having what it takes to climb the corporate ladder" is what gives your offspring a better chance of survival, then that is what is being selected for.
I don't think it's a stretch to say that, even in the least developed areas of the world, this is no longer the general case.
Humans are no longer subject to natural selection, since nearly everyone survives to breed.
> Natural selection only works if unfit individuals
> are killed off prior to breeding.
> since nearly everyone survives to breed.
Natural selection works strongly when group A dies before reproducing and group B does not. It still works, though more weakly, when group A has an average of 2.0 offspring and group B has an average of 2.1 offspring.
In some parts of the world, natural selection is still significant (the common example: sickle cell anemia drastically increases malaria survival). In many parts of the world, though, differential reproduction appears to be a result of culture / religion / personal choice; it's not well understood how much this relates to genetics, and therefore not clear how much it deserves to be called "natural selection".
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 those choices are inheritable traits (i.e. genes influence your choice of mate), that's textbook natural selection.
> even in the least developed areas of the world, this is no longer the general case.
A very large portion of the most successful pride of lions probably also breed, since they're not worrying as much about food or predators. Does that means the entire species is not evolving?
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 the relative proportion of various genes within the population.
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.
There are two forces at work in evolution. Natural selection (survival of the fittest) and sexual selection (reproduction of the sexiest). Out of the two, natural selection is by far the weaker force.
> Intelligence and other positive characteristics don't seem to get involved in whether they have surviving offspring today the way I imagine it did a few thousand years ago.
You're thinking very narrowly in the "survival of the fittest" mode.
You're ignoring sexual selection entirely.
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.
And, of course, the quality of your offspring matters as well and is determined by mate choice.
There's plenty of evolutionary pressure around today. Actually, I would say it's far more extreme today than ever before, especially in our urban areas.
I can't stress this enough, but there is simply no goal for evolution. Up until relatively recently, it just so happened that larger brains and other features we consider 'human' have been beneficial. Even if it may not be a big factor now, don't decry it as evolution being 'dead', or even worse, that people are devolving.
If certain genetic traits allow certain people to pass their genes down to more offspring then you have all you need. It's a very simple concept with major consequences.
It is good to know the name for that.
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, you're essentially providing a means to life for others. If your business is successful, you will have brought life to others via work for possibly generations(which essentially means others can provide a life for themselves and their families). I know that's a bit of a reach, but it's probably true to a small extent, at least in first world countries. Hundreds of years ago, I completely agree with you.
We live in a world where your work can potentially impact billions of people. Sure, you may not reproduce, but you may have enabled many others to do so.
That billionaire is giving his wealth away because he wants better social standing, etc.
In the end, evolution doesn't favor altruism and we have mechanisms that actively discourage it. If that weren't the case, Mother Teresa would have been the happiest person on earth (she wasn't).
> Even if you don't have children, by simply starting a business where you employ many people, you're essentially providing a means to life for others.
The businessman isn't helping others to reproduce. He's being exploited by his employees for their own benefit.
Your example fits within the confines of a parasitic relationship. In evolutionary terms, he is getting nothing from the relationship ... while they are reaping the rewards.
In reality though, even if he didn't start the business ... he still would not have reproduced, so his starting a business is irrelevant and was simply used by others to improve their circumstances.
It's a valid point. One should not be so quick to dismiss ideas.
Another example is the ants. A gene that gives workers good abilities will help the hole colony, even if the worker themself do not reproduce.
I may have an evolutionary interest in supporting my nieces since they are my sister's children. However, I probably don't have an evolutionary interest in supporting my nephew since he is my wife's sister's child. Biologically I have zero relation to him.
You're previous point, though, is spot on. In fact, I think we have genes just like that and not with regard to just strength. You might have a brother who becomes very famous because he's bright/sociable/etc. and your business prospers in the process, allowing you to have more kids. He wins that way, although indirectly. I think this happens a lot.
That's why it's such a pain to talk about these things in such simplistic terms ... life is just so much more complex and frankly, the evolutionary process is so brutal that there really aren't any losing strategies around. You can bet if somebody is doing something, they're benefiting somehow ... we just don't know how yet.
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.
The comment on which I commented said something along the lines of "you might as well just die if you don't reproduce", in reference to evolution. Yes, that is true (in regards to carrying on genes), but that's not the point I was making. I essentially said in today's world, if you're successful in establishing a business which creates jobs, you are essentially harboring other's abilities to reproduce. I guess you could say you can "indirectly reproduce" due to globalization and technology.
As the article discusses, the major characteristics of human populations in the recent past centre around demographic changes i.e. small populations where drift dominates, giving way to massive population expansion, where mutation and drift likely play a much more powerful role than selection does (for nearly neutral variation, which is the vast majority of variation).
This could potentially change if the human population ceases its expansion, stabilizing at a greatly increased level for a long period and with high levels of gene flow. In this case, selection could have more of an impact on nearly neutral variation than it previously has.
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).
I.e. smarter individuals have less (or no) kids.
Selection is always active.
First, there is sexual selection, not just natural selection, and there is no reason to assume that is not important today.
Second, as the article says, there is more genetic variety than before - we accumulated a lot of variation in recent millenia. That's the necessary foundation for selection.
Finally, a quick look around shows that some people have more children than others. You mention "Intelligence and other positive characteristics", but the fact is, it isn't clear intelligence was ever more important than say brute strength/social skills/etc. in our evolutionary history, so the fact it isn't the main factor now says little. But there definitely are factors that do contribute to having more (thriving) children today, and we are selecting heavily for them, for better or for worse.
The juxtaposition of intelligence vs. social skills is amusing given the Machiavellian Intelligence Hypothesis, which suggests that our general intelligence basically evolved precisely as a means to get ahead in the social games that are relevant for sexual selection.
If you can reason abstractly about what some rival is going to do and examine the "game tree" of potential actions, that is surely an advantage both for sexual selection and, say, debugging or proving theorems.
So while people are saying that evolution is "selecting for less intelligence", this may be a short-term effect in which we are first as a species shifting to stronger reproductive urges at the expense of general intelligence, and only then increasing intelligence in a way which doesn't allow philosophical objections to having children.
But evolution is pretty complicated, and difficult to reason about. Other people have also mentioned the "selfish gene" effect, in which altruistic / kinship behavior can be good for a gene, but suboptimal for an individual. It's possible some weird effect like that is going on also.
Also I am not sure you understand what "mortal coil" means:
You don't think that, say, genetic engineering will change the genome? I'm betting we'll be primarily artificially designed by the end of the century.
I did not know that - I really thought "mortal coil" meant the human body. Now that I know I'm wrong, nevertheless I must point out that qualifying "coil" with the word "mortal" is not only misleading but empty of meaning.
The Wikipedia article says that "mortal coil" = "the bustle and turmoil of this mortal life" but I do not believe that "mortal" fits well as an adjective for "coil" just because it refers to a "mortal life".
It seems like a very tenuous connection. Not one of Shakespeare's best poetic terms by far.
EDIT: Thanks for teaching me something interesting today, hnriot.
I'd like to think it is a poetic reference to our DNA.
To stay on topic, I agree with the parent. I think we have reached a point where our genetic makeup is no longer the primary factor determining our destiny as a species.
One could say that intelligent design now trumps evolution, as it were.
Depends. I can envision a lot of scenarios where infectious disease wreaks havoc on our species. Random mutation might have a significant impact on who would survive such a scenario and I don't think we (as a species) are anywhere near being able to circumvent natural selection of a sufficiently dire infectious disease. jmho
It's not only our own biological evolution that deeply affects us.
> Artificial interference is going to kick in long
> before that
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!
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