Another look at falsehoods about evolution.
We previously addressed the falsehood "Evolution has stopped for humans" and concluded that background change in allele frequency independent of natural selection does not just stop for any viable, continuing population. So, no, saying that "evolution has stopped for humans" is tantamount to saying that "gravity has stopped for my coffee cup" (which is sitting here on my desk minding its own business).
But this question is a falsehood at another level. In reality, there are two additional questions that are actually being asked when this question is brought up:
- Aren't humans no longer subject to natural selection?; and
- Aren't humans not likely to give rise to a new species?
The first assertion is a widely held belief with absolutely no foundation, so it qualifies as a true Falsehood. The second question is not so widely discussed. Here, we'll focus on the first and leave the second for another time.
Are human beings "still" subject to natural selection? This is a loaded question: Loaded with tricky words like "are" and "still" and "selection" and "human being."
Let's start with the Are-Still problem. A species is an entity that has temporal (time) and spatial (geography) dimensions. So an expanding population/species covers more and more geography over time, and so on. The "Are-Still" part of this question must be referring to some part of that time-space continuum. I think what is usually meant by "humans" is humans in this modern world of medicine and dominance over the environment, etc. In particular, it means humans as a population not subject to scarcities of food, ravages of predation, and suffering by disease. This is because in many people's minds evolution roughly equals natural selection and its effects, and natural selection roughly equals these listed aspects of the environment and their effects. The struggle for existence, the competition for food, and so on. And the struggle is over. (Remember, we're talking Fallacies here ... )
The other biggie, sexual selection, is often left out of the discussion. The popular mindset often seems to lack a concept of human mate competition or mate choice as factors in human evolution or human affairs in general. I think this is due to modern conceptions of monogamy. We fool ourselves into thinking that since there is the same number of men and women. and everybody eventually gets married to a member of the opposite sex, etc. , then there really is no mating competition or sexual selection. (Not true, not true, and not true.) This is a deeply fascinating set of assertions, beliefs, fallacies, and innuendos. Almost everything in evolution is about food and sex. But let's deal with the food first, and save the sex for later. (Always a good plan.)
So "Are-Still" part of this fallacy addresses a particular temporal-spatial chunk of "Human Beings." What about selection? Here the very simple (and meaningful but nowhere complete) answer is this: If we have removed with modern medicine, agriculture, and deadly weapons the parasites, predators, and food limitations from our environment, that does not mean that we are not evolving. What it means is that a large number of selective forces have shifted. Since we are talking mainly about stabilizing selection related to the ability to find food, avoid predators, etc. (maybe some directional selection as well), this mostly means that we are experiencing "relaxed selection." This is when selective forces that were there are no longer there (relaxed).
Many people confuse this with "not evolving." But remember our earlier discussion. "Evolution is change in allele frequency over time." And remember that mutations are common, and that most of them are weeded out. So relaxing selection almost always has to result in increased rates of evolution. So not only are humans not "not" evolving, human evolution may be accelerated in some areas of the genome. What a time to be alive!
But there is, as you may already be thinking, another big problem with this. The "Are-Still" construct in combination with the environment being less "red in tooth and claw," and all that, is problematic. And here we are going to get to the part of this discussion where many people will get mad at me. Sorry, but the assertion that we are not evolving because we have solved all of these problems is racist, classist, and Westernist. You are a bad person for thinking these things. But that's OK, we still love you and you can change.
Different human populations are very closely related to each other, reflecting both recent separation of those populations and long term flow of genes across populations that believe falsely themselves to be separate. There are people right now living in some far off part of the world, whom you've never heard of (nor they of you) who are among the most genetically distant from you right now, among whom are individuals who's great great great great grandson or granddaughter are going to have sex with your great great great granddaughter or grandson and thusly produce offspring. How do I know that? Because I traveled way back in time in an imaginary time machine I keep around for thought experiments, and made that prediction 100 years ago, 1000 years ago, 10,000 years ago, and 30,000 years ago and every time I was correct.
The modern human genome is fluid, it has been fluid for tens of thousands of years, and it will be fluid for whatever future exists until either the sun explodes or somebody really screws up and sends us into extinction.
Right now, as I'm sure you know, a huge part of the earth's population of humans does not have protection by modern wonders of science from parasites. A lot of people in Uganda are eaten by lions each year. People often starve. In other words, the usual selective forces are very much at work in our species, somewhere, indeed, in many places. Many different forces of selection are at work to differing degrees in different parts of the world and at different times (leading to genetic diversification?) and gene flow is ongoing across the planet (leading to genetic variability that defies sub speciation?)
It was possible, maybe, 25 years ago or so, to incorrectly but convincingly hold up Western Culture and Civilization as the place/time where many of the environmental forces of selection have been reduced. However, more and more people each year living in Western Civilization are less protected because of increase poverty and a widening gap between the "haves" and the "have nots." On top of that, some of the ravages of nature that we thought we were protecting ourselves from (like bacteria and viruses) are co-evolving with our defenses. And, presumably, or defenses are co-evolving as well. Yet another factor is the novelty of the environment. Some populations may have gotten out of being eaten by lions or running out of food, at least for the time being. But these populations have likely run into other problems. Obesity results in morbidity and mortality and may affect fertility or reproductive success in various ways. Obesity is growing to an epidemic in the US right now. Obesity as a consistent feature starting in childhood will certainly have selective effects. How can it not?
There are probably dozens of effects of "civilization" that have their own selective stories. So Natural Selection is still very much at work in the usual ways. Natural Selection in some areas is relaxed, thus changing evolutionary rates and trends, and not by any means eliminating them. And Natural Selection is working in relatively novel ways through the effects of changes in the environment caused by modernization.
So... Hypothesis: "Human beings are no longer subject to Natural Selection."
Falsehood Falsified.
More Falsehoods !!!
This post is one of a series on the topic of falsehoods. The following is a list of falsehoods posts in order:
- The Falsehoods
- "False Pearls before Real Swine"
- Falsehood: A baby is not the biological offspring of its adoptive mother
- Falsehoods: Has evolution stopped for humans?
- Natural Selection is Survival Of the Fittest (A Falsehood)
- Falsehood: Nature maintains balance.
- Is it a Falsehood that Humans Evolve from Apes?
- The poor and the dark skinned have more babies than the rich and the light skinned
- Acting for the survival of the species (a falsehood)
- Culture Overrides Biology (Another falsehood)
- What is the Placebo Effect, and it it getting stronger?
- Log in to post comments
Well put, holmes, very well put.
What about the assertion that science can have a dampening effect on some selection criteria? This seems reasonable to me. The side effects may end up with other selection criteria popping up that were heretofore unanticipated, but to say that science *can* dampen natural selection is intuitive at least.
Sorry, closer reading shows you dealt with this claim directly, saying it shifts around the selection criteria. Though this was what I said in the last thread, and you said was also a fallacy. So... hmm.
Positive growth of a population, which was not growing before, is evidence that the population is subject to reduced natural selection. This is the case with humans, whose rate of population growth has skyrocketed over the past century or so. The interesting thing is that the highest rates of growth have not been in the "developed" world, where one would think selection the most relaxed.
While your analysis is technically correct, isn't it also the case that genetically unfit individuals, like radio talk show hosts and Republicans, are currently allowed to reproduce, thereby polluting the genome and dooming us all?
Should post this stuff on MythBusters
Noel: it's a fallacy to think evolution must lead to what we think of as improvement. Think blind cave fish. Right wingnuts losing their higher brain functions might be similar.
;).
Without testing, how can you be sure gravity is still working on your coffee cup? Maybe it stays put because of inertia, static cling, a certain stickiness because you don't clean your desk often enough, or because the cup is too depressed to fly.
One of my daughters favorite sayings. "Stupidity kills, just not fast enough."
Eugenicists like (indeed, fetishize) the "natural selection has ended" fallacy because they fantasize about picking up the slack by culling the herd personally. Hannibal Lecter is the quintessential eugenicist.
You hint at this in the original post, but it bears emphasizing that the selective pressures on humans in developed nations are different from parasites and lion attacks, but no less real. Heart disease, obesity, cancer, type II diabetes, COPD, and many other illnesses that plague Western-style bourgeois populations are so widespread today because the conditions that lead to them were so rare in the past, and most people reproduced before they manifested. That's not so true anymore. Look at the burgeoning rates of type II diabetes in South Asian immigrants to the West, and, increasingly, in South Asia, as the South Asian middle class grows.
Assuming that civilization doesn't collapse in the short run, I would expect those illnesses to decrease in the next 10,000 years not so much because of the advance of medicine, but as a consequence of natural selection. OTOH, my confidence that Western-style civilization won't collapse in the near term is nearly nil, so we have that to look forward to.
Ever watch idiocracy? Human evolution at it's finest.
"It's what plants CRAVE!!"
I think in fact there's a deeper level of misunderstanding that some people have that causes this misconception. The catchphrase "survival of the fittest" makes it sound like survival is the issue - if you don't get killed there's no selection pressure. But in fact mere survival by itself means nothing. It's all about reproduction. So far as natural selection is concerned the "fittest" person in the world will pass on no genes if s/he uses birth control throughout life. The next generation will not inherit genes from that person.
Matt: Right, that deserves an entire falsehood essay all by itself.
Glenn @ 9:
Would your daughter mind if I edited that to "Stupidity kills, just not early enough."?
I've often thought that the widespread availability of contraception must be exerting a huge selective pressure in the wealthy part of the world. People who could afford to comfortably raise 6 children often only have 1 or 2, or even none at all.
A normal sex drive used to be enough to produce a large brood, but this is no longer the case. It's a simple case of previously adaptive behaviour becoming maladaptive in the face of a novel environmental feature.
It seems obvious that natural selection will now strongly favour people who have a strong desire to have children, so long as the desire has at least some genetic basis. In a few hundred years people who don't love children may be as rare as people who dislike sex are today. (Although, oddly, the latter do exist.)
So, what about homosexuals? How are they favoured via natural selection?
Human sexuality is extraordinarily complex and situationally adaptive. Think of it like cuisine. If something happened to make people not want to eat tomatoes, there would be fewere and fewer tomato eaters until there were none. Would the tomato eating gene be gone? No. There is no tomato eating gene.
How do homosexuals exist given a Darwinian world??????????? OK, we can blog about that. Look for it.
Homos exist because we help our less stylish sisters select clothes and make-up that makes them more attractive. I mean, they have some of the same jeans.
Oo, oo, I know! You're the anthropologist, though, so have fun...
Nuclear, {power & weapons} & other W.M.D.'s are just one of the issues that still place humans totally under nature, rather then the other way around.
As for human's 'speciation'...wouldn't humanity have to moved some portion of itself to Mars, (or the 'Vatican', an even more remote location, {L.O.L.!}), to isolate that portion over enough, ('geologic') time to see, a
'different' humanity emerge?
Nuclear, {power & weapons} & other W.M.D.'s are just one of the issues that still place humans totally under nature, rather then the other way around.
As for human's 'speciation', wouldn't humanity have to moved some portion of itself to Mars, (or the 'Vatican', an even more remote location, {L.O.L.!}), to isolate that portion over enough, ('geologic') time to see, a 'different' humanity emerge?
Selection works most effectively when resources are limiting and competition for those resources is enhanced. Thus, the growth in human populations does not mean that there is no selection on humans, but that the competition for resources in some areas have been shifted to a new level, or carrying capacity. Food was once a limiting resource, but with the Green Revolution, no longer was a limiting resource (except where inequities in resource distribution occur). Wiens and Rottenberg back in the 1970's (?) showed that shrubsteppe bird species exhibited strong seletion once every few years, not every year. Work on Galapagos finches by Peter and Rosemary Grant also demomnstrate that selection is episodic, and not continuous. The existence of wars is evidence that resources are limiting.
Greg and others,
homosexuals exist because a)sexual orientation is complex, involving the expression of different genes, not just a single on and off switch, and b) sexual preference by itself doesn't determine likelihood of reproduction. In a clan/tribal society, such as prevailed in the pre-industrial world and still widely exists, marriage and mating behavior were not at the sole discretion of individuals. It was often (and still is) decided on the basis of access to resources, alliance advantages and other reasons not directly related to the personal choice of the individuals involved.
Taken together, its fairly clear that homosexuality is not a simple trait that is easily filtered out of the gene pool by natural or sexual selection processes.
Some studies have indicated that high hormone levels that related to hyper-sexuality (more manly or more womanly) also lead to lower reproductive capability and higher incidence of other health problems. So some stable level of homosexuality may in fact be advantageous to the overall genetic health of the population
The best evidence we have strongly suggests that food was not a limiting factor for humans in a very very long time. The invention of horticulture certainly increased food stress in many populations at first, and after that it was a mixed bag.
http://www.starvation.net/842millionstarveinthemidstofplenty.htm
Jim: Nice link, but what does it mean?
I agree with everything said thus far, but why not consider taking the question a little further.
Evolution is both a word and a point of scientific fact, but its not necessarily an accurate term . For instance, let's look at all life as a series of interlocking but hierarchical systems that change not only because of inherent design, but integration of design variations relative to the host environment.
In other words, in any given living system, change is necessary: that which is there before the process of evolution. What we believe is evolution is probable: that is, our understanding of what evolution does and does not do over a period of time is constructed from our common understanding of environmental change relative to general and specific stasis.
And there is the constancy of occurrence of either in joint, direct or inverse relation to the other, relative to the greatest common general circumstance of simple change or complex evolution and the least common individual result of evolution and change integration.
Homosexuality, or any sexual identity thus arises within our human system, not because of an inherent gay gene, but because of an inherent probability of the overall system to generate variations that add to the system's stability and longevity relative the host environment over a given period of time and selection.
It sounds like I'm nitpicking, but I'm working on an overall idea that this line of reasoning directly relates to.
Thanks
Thomas
Thomas: At the base, just because something exists (a trait, a behavior) does not mean that there is a direct genetic link.
To understand human homosexuality one merely has to understand that sexuality in humans is only occasionally about having babies. In other animals where bonding, erotic behaivor, sex, is also not always directly about getting the sperm and egg together, we also see lots of "homosexuality".
When it comes to homosexuality, the "sexuality" part is the part that is selected for in an evolutionary sense. The "homo" part is icing.
While the genes of a male homosexual aren't passed on to his decedents (because he normally does not reproduce), it is likely that his siblings also have the same genes. So it might be the case that having a homosexual brother might increase your ability to reproduce and pass on those genes to your descendants.
For example, the gene might promotes attraction to men. In men this manifests as homosexuality, but in women manifests as having more offspring. The net effect might be an advantage. See:
http://www.reproductive-revolution.com/female-fecundity.html
Also, an unmarried sibling can be a big help in raising a family.
I imagine we're evolving the ability to live with more people, in more crowded conditions, to handle more complex interactions, e.g. knowing more than a hundred people, to delay gratification and to resist the urge to overeat and underexercise in times of ease and plenty.
I know of at least two instances where homosexual men were married and fathered children before coming out of the closet. Homosexuals do reproduce. Inclusive fitness is a measure of how many copies of your genes get passed on to the next generation. We all know of examples where childless individuals have contributed to the success of relatives, who bear copies of some of their genes.
Greg: I honestly have no idea why homosexuals exist. It is perhaps the greatest unsolved riddle in human sexuality.
I've read about quite a few hypotheses, but none of them sound very convincing. If you can explain it, I'd very much like to know about it.
I'm fairly satisfied with the answers so far, although I crave detail. But the answers seem, also, to apply mainly to male homosexuality. Historically women have often enough not had a choice about whether or with whom to reproduce, regardless of their preference.
Selection certainly does still have an effect humans, however from experience, there are a number of people who are not necessarily happy with the direction in which natural selection is taking. Fitness is directly correlated with fecundity, and the individuals who produce most offspring are not usually the same individuals who contribute most to society.
@Mara. Precisely. Though eventually food, water or land will become a limiting factor upon human population growth, until humans either establish a space (Mars?) colony, or some tragic event reduces the human population significantly (or sends us into extinction) The large size of the human population base gives a better potential for faster evolution, and survival should such an event occur.
The idea of more reproductive success for organisms with certain traits which would cause said traits to be passed on and made more common being applied to humans today is retarded. Sorry, but very nearly every one of us can reproduce at some point regardless of our fitness for it. Maybe humans are just that perfect. Or maybe you're applying hardline science where subjectivity does not exist to one of an extremely small number of species that doesn't choose who to mate with based on genetics or fitness, but on subjective values. Maybe we can attribute our astonishing and never-ending population growth to our free will which we likely developed through a very successful evolution of some type, but I'm really not seeing natural selection hitting us very hard nowadays (non-existent man-eating lions eating everyone in Uganda aside). I also noticed someone mentioning people who say it doesn't apply are eugenicists. I'd have to argue the opposite. Supporting the idea that natural selection still has an effect on humans today and can't be changed could be seen as support for not allowing "unfit" individuals to breed because that would weaken the species and go against the infallible law of survival of the fittest.
Human as species has evolved social and technological advanced that rule of natural selection does not apply. If it be technological advanced human society can wipe out other society with Nuclear Bomb/technology and be justified. Then Hiroshima and Nagasaki will be justified. By our social evolution we are supporting deaf dumb and people in vegetative state who otherwise would have been wiped out by natural selection. So social species reduces natural selection process.
Other animals don't put forth laws that allow children with major defects to be born and taken care of through the burdening of the rest of the population. Other animals haven't the obvious morality issues of allowing criminals and psychotic and mentally unstable folks to have all the children they can have. Religion and its pressures to force rape victims and other factions of unfit mothers to have their children despite their inability to care for them.
Yeah.... We probably are fully subject to Natural Selection...
Okay I feel I need to pwn the author of this article.
[And the author feels need to delete your stupid post. -gtl]
Pre civilisation struggle and wars have acted to "select out" both the most brave and the most aggressive. With "robotization" of future wars, this may no longer apply. Selecting out the most aggressive has aided human cooperation. Selecting out the most brave has encouraged the herd like cowardly aggression amongst males.
Yes, the brave dieing to save family, tribe, or nation is perpetuating their own brave genes, but over time there will be a negative effect.
This is an article that sticks to certain technicalities in order to drive home a message that is irrelevant to reality. It is like a trying to say that when one using a vacuum-creating device it is wrong to claim that he has created vacuum cos there's still atoms in there no matter what, while the essence is that within a certain container there is an adequately small concentration of matter that allows a certain application. Although it is generally a serious text apparently written from a very intelligent individual, it gets a little bit ridiculous when it mentions sexual selection, which is nowadays clearly vital when it comes to having sex and as clearly irrelevant when it comes to reproducing, and especially when it uses the argument that still nowadays there are some people somewhere in Africa that are eaten by lions. The reality is that homo sapiens sapiens is right now slowly (but fast for evolutionary time scales) becoming less fit in almost any imaginable aspect (I could let the author do his best to manufacture his most suitable definition of fitness, but no micromanipulations could allow him make the sapiens of tomorrow score better than those of yesterday). A cute example that captures reality in a much better way than this article does, is that a professor of quantum field theory, made so by his very instincts trying to promote him as a breeding biological machine, isn't even having the offspring by the one breeding partner "that corresponds to him" or "that he deserves" as instructed by this local, culturally-induced trap of monogamy in a species that evolved within groups for a huge amount of time, because he doesn't have any time left from his research in order to properly raise children; whereas someone who puts a kerchief on his spouse's head, burns her genitals and non-critically believes one or another thing he was told at some point, is having his seven babies, allowing his genes to propagate accordingly. Another cute example that carries the right message is that sapiens have the authority to create fluffy little things out of the wolf-bison game, so that they can cuddle something with less responsibilities than having a human baby, they also have the authority to make shiny, hyper-nutricious tomatoes out of star star star star, but who are they to take measures and impose rules so that they themselves become better generation after generation... Saying stuff like "background change in allele frequency independent of natural selection" is accurate, alright. To use the -correct- gravity counter-example, it is like the author -should have- said that by saying that "gravity of the earth has stopped for my cup of tea, which I am holding somewhere in Alpha Centauri". Well, the accurate thing to say is that it hasn't stopped, but the message that carries the actual, non-misleading information is that it has.
Thales, look up the word falsehood and reread!
How could my reply have been a result of misunderstanding the meaning of the term "falsehood"?
Because claiming that sticking to technicalities (IOW the meaning of words taken precisely) is somehow irrelevant is a falsehood.
You may also want to read the topic heading too.
That's why I gave not one, but two examples of how in certain cases trying to be accurate with certain details can be used for giving a completely wrong message. I'll give a third one. For a number of complex reasons, it is a fact that right now on planet earth, the less ability of critical thinking a sapiens has, the more he reproduces on average, within a statistical framework. One can write an article about how the concept of fitness can be appropriately expanded in order to accommodate the dumbness as a local advantage for reproducing and claim that evolution still applies to humans (I normally use definitions that are not x-specific, where "x" can even be "our universe", but without having to be rigorous here about definitions, I hope my message is clear). But what kind of statement would that be? It is also a falsehood to claim that there is no interaction between us and far away constellations, but if one writes an article about this, the only thing he would achieve, besides mumbling stuff of the kind "strictly speaking", is to enhance the idiotic belief of people in astrology.
Thales, you need to read the heading.
It claims that the theory is a falsehood.
You know, exactly what you appear (though your writing is so atrocious and self-absorbed it's impossible to know) to be saying.
Feels like I am participating in a conversation with bots. No comment whatsoever in my blatantly clear remarks, just insisting that the theory is a falsehood. "Whether your personal life will change within the next month has nothing to do with the constellation of Taurus: a falsehood. The constellation of Taurus applies a force of the order of one to the minus bazillionth of a Newton to you plus some much weaker interactions of other nature." Here's my accurate article. Let's believe in astrology and have a breakthrough in mankind.
One to the minus=ten to the minus; my bad.
"No comment whatsoever in my blatantly clear remarks, just insisting that the theory is a falsehood."
No, they're NOT blatantly clear. Hence my question. What was not patently clear about that?
OK, help us out, then, you appear to be saying that "Humans are no longer subject to Natural Selection" is a falsehood. What is the falsehood?
Natural selection is the method by which changes in the alleles in the genetic makeup of a species become a change in the species. Natural selection is based on the reproductive capacity of any organism will outstrip the supply of necessary nutrients for that organism.
Our alleles still change.
Our reproduction is still able to increase population exponentially.
What then is the cause of what you see as the breakdown of this when it comes to species change?
"it is a fact that right now on planet earth, the less ability of critical thinking a sapiens has, the more he reproduces on average"
1) She's involved too, you know. Did your mommy not tell you about the birds and the bees?
2) The less intelligent the human, the lower their ability to provide for their progeny and the more likely they are not to survive. Surely this indicates your claim here is wrong.
Oh, and
3) That doesn't indicate natural selection has no effect on humans.It may indicate you're pissed off that you're not getting your leg over, but about half of humans never reproduce. And that figure has been true for as long as we can infer the rate.
OK, I will try to be further clear.
It is possible to formulate a generalization of the theory of evolution to accommodate the way allele frequencies change in humans and other civilized species (I have made a generalization myself that seems to be consistent even with every coherent universe). Besides background changes, there will be changes induced in a systematic manner by one reason or another.
However, the notion of natural selection as we know it from our local context (i.e. life on earth based on DNA as the replicator), as described -also- by evolutionary game theory, completely falls apart. Examples of elements that give rise to a "successful" individual in the conventional biological sense are having lower sense or responsibility, having less understanding and/or access to pregnancy control measures, not being competent in fields that require devotion, having no ethical barriers in contributing in sperm banks, possessing technology that can allow severe conditions to survive and reproduce, to mention but a few elements that are completely irrelevant to the Darwinian paradigm.
Some things have changed in our civilized society; there is no doubt about that. To address those changes clearly and argue how they can be correlated to allele changes is a tedious task. This article is trying to convince that despite those changes, sapiens is still subject to natural selection. Well, formally speaking this is true, but not only is it a non-informative statement, it is also completely misleading. It is a statement that goes to a level of accuracy that has no value in grasping the essence of what has happened in sapiens evolution during the last few thousand years, and is presented in a way of leading to a conclusion that is opposite to what is essentially true (I have already given what, six counter-examples of statements that are accurate and meaningless/misleading?).
I will let you construct a vector with phenotype/generalized phenotype components anything, absolutely anything you like, but we agree that having phenotypes that give you additional rights without cost is an advantage (e.g. if I can have the potential to climb or jump higher, I have an advantage; I can choose not to if I want, but my genome allows me to do so if I choose, or I can solve a problem if I want to, my genome provides me the right to solve this problem, compared to not being able to solve it). I claim that sapiens gene pool from 2.5 thousand years ago would score better in almost every conceivable component of such a vector compared to today's sapiens gene pool. You can think of kids of Harvard being raised in identical conditions as citizens of ancient Miletus, then participating in a competition of anything you can think of and losing badly in every single one of the,. As a matter of fact, I challenge you to name one, only one aspect of phenotype in which today's humans can perform better than their ancestors on average.
To make a pause here, it is like saying that it is accurate to say that humans are still subject to evolution and well, we are getting worse in every conceivable aspect.
Of course the differences in allele frequencies are not that significant. One could say that humans are getting worse very slowly for the time scales we are used to from our personal experience, but very fast for the evolutionary time scales.
I find it remarkable that sapiens is a species that has intervened in the evolutionary history of a vast amount of species on the planet, not just by -more or less directly- compromising or wiping tons of species off the face of the planet -which is something a bacterium species is also capable of-, but also by breeding a countless amount of species for his benefit. The species that he doesn't breed for his benefit is himself (he has done it to a minor extent in exceptional cases throughout historic times). And worse: as if human civilization is miles away from introducing some kind of political algorithm that would allow itself to evolve fast, along with its cucumbers, is not enough, it has ended up being in a state in which being mentally compromised is an advantage, among many other nonsense factors governing the breeding dynamics of our species.
We are essentially cavemen in terms of allele frequencies. Which cavemen are developing science and technology, that is growing exponentially, building further and further on existing knowledge, while our gene pool, giving rise to the phenotypes that are supposed to manage such developments is slightly inferior under any possible definition (a phenomenon that can also explain the huge, ever growing gap between science, which is getting doubled every few years, and society which is essentially equivalent to the one we had when we came up with agriculture).
I know you can find flaws in this text; I could have written everything rigorously if I had a thousand pages at my disposal. But really, that's what you have to say about all this? That the allele frequency still changes somehow? That formally speaking humans are still subject to natural selection? The actual answer to which is "not really?"?
PS: Now that I think of it, humans in Europe of the Middle Ages living in pastures did manage to develop some resistance to a set of bacteria, that they didn't have before, I have to give you that.
At this point I have no idea if Thales thinks natural selection is a factor in current human evolution or not.
But I think Thales is against astrology.
Perhaps he is making the point that one should not be what is sometimes called "hyper skeptical" ... i.e., saying that since some distant celestial body technically applies a small gravitational force everywhere, or light, or whatever, that one can't say that astrology is complete wrong.
If that is the case, than Thales is saying that my statement that there is no meaningful reduction in the importance of natural selection as a force just because humans passed this or that imagined threshold is hyper skepticism, that force is minuscule and really doesn't count, like the tiny amount of gravity/light that arrives on the earth from a distant object.
However, I'm not saying that. I am not being hyper skeptical. I'm saying that natural selection is an important force in current human evolution.
I'm confused about Thale's comments regarding intelligence, and I'm wondering if Thale is thinking that somehow intelligence, or its evolution, is special and distinct, i.e., not subject to selection, or that it is the main thing subject to selection. That really is utterly unclear.
Wallofbullshit detected.
Mr. Laden, I think you seem to be an extremely intelligent author who wrote, in my opinion, a bad article about this topic. If you think of an artificial environment for the bison, where if the bison has no fur and thiner skin you put him in air-condition, if it has no horns, has weaker muscles to fight and run, you are gonna have a machine to shoot the wolves, if it can't chew the grass you will push it throw its mouth with a tube, you let him breathe and claimed that one can appropriately generalize the conventional Darwinian paradigm in order to accommodate this clearly unprecedented situation (a wolf-killing robot is some kind of environmental factor after all), it would be a not so informative accurate thing to say. The average reader of your article would have liked to have an answer to the question "is the bison still really evolving?", for which he would get the wrong message. But trying to fit elements of a conventional Darwinian approach under the carpet would not be acceptable. In parts of your article I feel we live on a different planet. Sexual selection? You see that handsome guy with the abdomen muscles and you think "oh my, that guy should have at leasts 100 babies"? Or instead that he has greater chances of having several sexual partners? On which planet did you make those observations? A simple alpha male of a simple hunting tribe used to breed with all females of the tribe. The probably most intelligent human of the last couple of thousand years, John von Neumann, had what, one? A fanatic kept alive by drugs and medical equipment designed by a genius in order to put a kerchief and burn the genitals of his spouse has 13. If your approach is right, I don't mean what I say in any racist way whatsoever, there should be some profound recent changes in fitness of Europeans compared to that for example Nigerians. In a few decades Europeans have seen their relative population on earth from about 20 to about 4 per cent and Nigerians within a few decades will be about 10 out of a tiny fraction. You can not claim that what used to happen with allele frequencies of human populations is still pretty much going on without serious discontinuities. Your model is supposed to describe the dynamics of the sapiens gene pool, not rely on the 5 people that were eaten by lions to reach a verdict.
I will not respond to comments of such level that include the phrase "your mom" in such a conversation.
breathe=breed, I apologize, I have made several typos.
Your mom.
Thales: "The average reader of your article would have liked to have an answer to the question “is the bison still really evolving?”"
The answer to that question is yes. As explained in the original post.
I'm not a good writer who happened to write a bad article about a subject I don't know much about. I'm a PhD wielding evolutionary biologist who wrote an OK article about a topic in which I am an expert. That does not mean what I said was correct. But it does mean that your comments about what sort of writer I am are not relevant!
Go re-read the post and check back with us. Thanks.
Since you are an expert, you should agree upon the very evolutionary reasons that have led to such a dispute. We are "biological robots", optimized to perform in conflicts, excel, advertise ourselves, intimidate our rivals and so on and so forth (I won't take the Nobel prize of literature no matter how hard I try, but I hope you are aware of that fact!). Do you really expect that by outsmarting me in this conversation that you are going to convert this victory into offspring? That there's females reading this that will ask for your babies as a response to this post? Your eagerness to prove me wrong without having the slightest association of such an action contributing in your gene propagation, is actually proving me right. The probability density of sequences (basically 1 dimensional objects in this life tree of this planet) of our replicator is not the outcome of the same algorithm for recent mankind and rest history of life, including protobiology. Haven't you noticed? How can one extend the Darwinian scheme into a world where the actual reasons of our optimization are projected onto e.g. substitutes, simulations, peripheral phenomena? If your amazing fitness is converted e.g. into a career, where's the continuity with the Darwinian world?
Allele frequencies of sapiens are subject to change nowadays, but in a way irrelevant to what we mean by conventional natural selection. It is possible to accommodate what's happening into a theory of natural selection that is generalized appropriately. But the essential piece of information in this conversation, the extract in a handful of words, is that humans are at the moment getting dumber, as well as genetically inferior in almost every conceivable aspect, as compared to themselves in the recent evolutionary past. The fact that you are an expert does not make your claim correct. Your arguments should :).
Aw, you totally should have just said "Your mom", would've been amusing if the only response he got from everyone was "Your mom".
Go on, Greg. You know it makes sense...
Unlike thales' words...
Dr. Laden, I do not agree with your article. I don't live on a planet where sapiens are undergoing a "relaxed selection". I disagree with the extension of the Darwinian scheme that you are trying to make and it particularly becomes clear by the way you discuss sexual selection.
I have already interfered a lot with your blog. Let me end this with some humor. Let me describe a situation on a planet where your article would have been accurate in my opinion.
Guy walks into a bar. Girl talks to him.
-Nice muscle system.
-Haven't trained a day in my life. All inherited.
-Impressive. Give me your best riddle solving pick-up phrase.
-I have proved Poincare's Conjecture.
-Are you serious? You're a genius! That's a manifestation of tremendous capacity for problem solving. I am so tempted to breed with you. I'm 14, my sex cells are in the best possible shape, your apparent fitness is such that I don't even dare to ask for any parental investment. What do you think? Come over to my place and breed?
-Sure! Just a bit of time investment for the coitus. That's practically nothing compared to the benefits. Last week I went for 8 offspring.
-I would do the same if I were in your shoes. Not that you are under immense pressure by predators or you are gonna be in lack of food whatsoever. But still, you are not a bearer, your apparent fitness is more than a fair trade-off for being a nest male, why not propagate your genes accordingly?
If we lived on that planet Dr. Laden, your article would be right on the spot. On our planet (we call it earth), the guy who made 600 pages of proof for the Poincare's Conjecture lives with his mother and cat, while someone is breeding non-stop in the jungle simply because he hasn't heard of the term "condom" before. That's not relaxed selection; our game is a different ball game, governed by an entirely different set of rules that have nothing to do with the Darwinian scheme, not if you tie me and you hold a scorpion above my face! Things that are mainstream in one or another culture of sapiens regarding the breeding dynamics you need to struggle searching in 4 billion years of life to find one counter-example!
What we ever meant by "evolving" has not applied but to a marginal extent in sapiens for the last couple of millennia.
"So Natural Selection is still very much at work in the usual ways."
No, it is not. When I say generalization in this context, I mean a generous one. E.g. "the probability distribution of DNA sequences on space and time depends on their environment". That's an exaggeration, this is a more general definition than what we need, but just to illustrate we need to go far from natural selection as we know it to describe the dynamics of the sapiens gene pool.
Thank you and I apologize for typos and any badly written text (although I believe my messages should be clear).
"Allele frequencies of sapiens are subject to change nowadays, but in a way irrelevant to what we mean by conventional natural selection"
There you go. That sentence is correct. Now, really, go and read the post for comprehension! You are almost there.