It sounds like post-hoc rationalizing to apply this logic to humans.
> Humans have evolved in symbiosis with our gut flora. Why would we want to eliminate them?
It complicates the system to have to maintain a balanced internal ecology; look at the probiotic yogurts out there to see how often it gets out of whack in the real world.
With the complexity of human social interactions, it would bewildering were it not the case that there are at least some small instances of genetic advantage being conferred to population groups based on the existence of non-reproductive members.
The concrete case where I've heard this considered is (strict) homosexuality. Logically, in so far as there's a genetic component to such, one would expect homosexuality to be eliminated from the gene-pool over time. One of the guesses as to why that has not happened is that homosexuality may confer some social benefit which increases the overall survival and reproductive capacity of the genetic group to which the homosexual members belong. (There are other plausible explanations as well, but it's not incredibly far fetched to believe that such could be the case.)
More likely, the gene that predisposes us to homosexuality (it doesn't cause it, as MZ vs DZ twin studies have shown that homosexuality has well below 50% genetic cause, with a much higher component based on individual environment, both pre and post-natal) is either beneficial in some other way (for instance, a recent study showed that female relatives of homosexuals tend to have more children, which could mean that the heritable bits behind homosexuality actually increase female reproductive rates enough to overwhelm the negatives on the male end), or live close on the chromosome to another gene that's more important, so the gene tends to stick around because of linkage even if it's harmful in some cases.
[1] The "gay uncle" theory relies on the fact that it's family members, i.e. people that are causally likely to share the gene in question, that are helped by the behavior. Google "kin selection" and "group selection" to understand the difference - briefly, kin selection is a totally legitimate effect because a gene helps itself through its prevalence in a family (and specifically, due to the fact that the gene will appear in the offspring that the gene helps make possible, even if it comes from other individuals), but group selection is completely bogus, because Prisoner's Dilemma-style defection is always the right strategy for a gene there.
I also wonder about the 10% figure.
The assumption that you'd need to make sure that 1 additional child would need to be produced per gay uncle misses out on the possibility that the increase in offspring comes in later generations.
The effect could easily be much more than just one child per gay uncle, depending on how far down the tree of offspring you'd be willing to accept as a direct effect of the presence of a gay uncle higher up in the tree.
Also, gay does not mean sterile, but I take it that you assume for simplicity's sake that gays don't have children, or that if they do that they're not subject to this particular explanation since it concentrates on gay people without direct offspring.
Wait - if twin studies showed bellow 50% correlation, how can it be pre-natal environment ?
But you make a stronger point in the footnote, his initial argument relies on group selection and can be dismissed on those grounds, no need to debate how that relates to homosexuality.
Probiotic yogurts are mostly marketing as far as any research I've seen in metagenomics. I'm unaware of any scientific evidence that eating Activa gives you anything more than expensive poop. However, legitimate medical probiotic treatments tend to be the result of mucking with gut flora, for example, in other ways, such as taking antibiotics (I'm thinking of stool transplants for C. diff which is a fairly simple, disgusting, and effective treatment). But my point is really, how much does it complicate the system because I don't think anyone is aware of a working alternative so this could be the simplest solution to get all of the functionality we need.
If I were engineering the human body, I would replace the liver with a system of symbiotic flora. It would be easier to replace without having to figure out how to clone organs or take a liver from someone else.
From Wikipedia, "Rodents raised in a sterile environment and lacking in gut flora need to eat 30% more calories just to remain the same weight as their normal counterparts."
I couldn't agree more. Humans are (mostly) monogamous and are born from combinations of parental genes (with the exception of the mitochondrial DNA). Thus the properties we inherit are directed. This is why we bully: a group of humans hate dissimilar properties an individual has.
As much as you hate it, we are heavily dictated by our genetics: identical twins are often mistaken has "having the same thoughts" to the point of mistaken telepathy.
It irks me that many attempt to explain away dysgenics as inherently impossible. As the article points out, simple changes to our metabolism can improve our bodies greatly. Natural selection is one tool of many that powers evolution, as evolution only rewards those who reproduce the fastest.
When we talk about a long-living Nobel Prize winner that doesn't have children, the things that such a person does "for the world" are irrelevant to the propagation of his/her specific genes, except as they directly affect the people in the population that actually have those genes. If their contributions help everyone equally, their genes will not rise in frequency within the overall population, and hence, the mutations are failures, genetically speaking.
Mutations? Shuffling a deck of cards doesn't "mutate" any cards in the deck, but you will also never get the same sequence twice. I think you are mixing things up a bit about how our genes work from generation to generation.
I think that must just be an opinion. It falls short of observing everything relevant to what our genes, and what we as individuals and as species are "winning" for. It might work to say such a thing on the meta scale, but it just doesnt work to say that about someone whose DNA is undoubtedly fully represented in his/her extended family, et al. For instance, my opinion of what I would call a genetic failure would be one which persists continually without ever contributing to the greater human intellect.
It's also worth noting that we have little knowledge of genes anyways, but that might fall on deaf ears.
tl;dr Someone who is a long-living nobel prize winner is IMHO, a genetic success, regardless of procreation.
I understand perfectly well the distinction between mutations and crossover, but I stick by my original language - to a large degree, competing alleles do ultimately arise via mutation (including insertion/deletion/other funny business), not crossover, which primarily just randomizes selection between different alleles rather than altering them in detail (human crossover probabilities are roughly 1% per million base pairs, which is too infrequent to be doing much bit twiddling within genes themselves, though it will occasionally happen).
> tl;dr Someone who is a long-living nobel prize winner is IMHO, a genetic success, regardless of procreation.
That's fine, but "genetic success" in the context of evolution means quite specifically that copies of their genes are more likely to be present N generations down the line than copies of competing ones.
In this sense, if your particular set of genes enables you to help all humanity equally in some significant way, you're doing your own genes no particular favor unless you somehow help your own family out more than others. That's not a moral judgment by any means, but it's the nature of the game of evolution...
>It sounds like post-hoc rationalizing to apply this logic to humans.
I don't think so. Perhaps it is less rational to apply this reasoning to the ability of a society to produce warriors (i.e. abundance of young males) but more so in philosophy, science, ideas, inventions, and thought. So long as these evolutions of thought are not lost to time (and they are far more fragile than genetics which sex is the only communication required) then it can be argued that they often times have a far greater impact on the human species as a whole than the passing of any certain genes over others. [1]
Humans are remarkable and unique in regards to this in the animal kingdom as far as we (humans) can tell.