Your disappointingly vapid opinion piece is not going to encourage your book, Benjamin Oldroyd. There’s nothing there. I’m referring to an article titled Epigenetics and evolution: ‘the significant biological puzzle’ of sexual orientation. The author is plugging a new book, Beyond DNA, and is trying to persuade us that maybe he has an answer to why gay people exist by going through a couple of hypotheses.
The first hypothesis is that it is a product of kin selection.
Briefly, the kin selection idea is that a gene that promotes homosexual behaviour can spread in a population if homosexual people contribute significantly to the reproduction of close relatives. Although this idea is plausible, the lack of any genetic marker that is reliably associated with sexual orientation is a strong argument against it.
There is no such thing as a gay gene, though, so you can’t postulate the existence of one and build up an adaptive scenario around it. I agree with Oldroyd. It’s a useless hypothesis.
Another idea is that there are antagonistic alleles.
The “antagonistic alleles” idea is that there are certain genes that are selected in different directions, that is, positively selected in males, but negatively selected in females and vice versa. Hypothetically, because no such gene has been identified, a gene that promotes testosterone production could be at a selective advantage in males if it promoted traits such as muscle development, risk taking, opposite-sex sexual attraction and increased sexual attractiveness to females. But if the same gene were expressed in the same way in females it might be disadvantageous for reciprocal reasons. This means that selection could pull in different directions in males and females, maintaining different gene variants in a population. By that I mean, gene variants that have different selective advantages in males and females can potentially coexist in a population because neither is unambiguously better. If so, sexual orientation may be more fluid than one might expect based on biological sex alone. (Well, “der”, I suspect you are now thinking, but please don’t shoot your even-handed messenger.)
He explains it well, but…”might” and “could be” are not evidence. Again, this hypothesis falls apart because there is an absence of evidence for the existence of such alleles undergoing differential competition in males and females. It’s another adaptive just-so story. It’s a useless hypothesis.
Therefore, if you rule out two hypotheses, the third alternative must be the answer, right? Cue dramatic entrance of Intelligent Design…no wait, not that. Oldroyd knows better than that. But it’s the same rationale: we think we have evidence against the conventional alternatives, therefore that counts as evidence for a different hypothesis.
No, it does not. Now the magical mcguffin we’re all looking for is epigenetics.
The epigenetic hypothesis for the widespread occurrence of human homosexuality is based on the possibility of epigenetic inheritance of adjustments to a foetus’s testosterone sensitivity. Like most other epigenetic marks, sex-specific epigenetic marks are established anew in the early embryo following fertilisation.
Substituting hypothetical “epigenetic marks” for a hypothetical “gay gene” gets us nowhere unless you’ve got something concrete and specific. If you do, that would be very interesting…but epigenetics, by it’s nature, is fuzzy and hard to pin down. That is not to say that epigenetics is non-existent — it’s very real and important — but that you can’t slap a simple causal explanation on many complex phenomena, whether it’s a gene or a epigenetic marker.
My preferred explanation is also a bit fuzzy. We have to get beyond the bogus genetic determinism that appeals so strongly to naive minds, and epigenetic determinism would be just as bad. I think we have to accept that human behavior is sloppy and variable as hell. We are built by a long chain of probabilistic interactions, from molecules bouncing around in a messy cell, to a tangle of cells communicating chaotically with one another, to incompletely specified individuals that are shaped by interactions with a variable, changing environment to end up as people with mostly unpredictable characteristics. Physics and chemistry are biased by biological constraints, but the end result is not rigidly locked in by your genes — there is a messy cascade of genetic, epigenetic, and environmental interactions that is skewed by evolution to produce a generally viable outcome, but is tolerant of variability.
We have to abandon these mechanistic notions of a clockwork biology that spits out adults who were specified at conception by the chemistry of nucleic acids. It just doesn’t work that way. We are all products of stochastic processes.
My personal belief is that evolution has worked to take a population of apes and favor a hierarchy of properties that are all weakly specified, and we’re lucky if the majority of individuals conform to that hierarchy. First in priority is cooperation, building a social environment that promotes mutual aid (we all know how poorly that often works out). The way I look at it is that biology is telling us to love one another…and then it is far less fussy about the details. We don’t need a deterministic explanation for why individuals vary, it’s the nature of how they are built.
We stumbled into something resembling civilisation mostly by chance. It’s all contingency. I am reminded of Stanislaw Lem’s spoof article “Kultur als fehler”.
Does he also have an answer to why straight people exist?
Typical.
SOMEONE forgot to connect the ground of the o’scope input, so it’s picking up all the EM crap nearby.
…which still makes a lot more sense than the “gay gene” (or “gay epi-gene”) blathering. If Oldroyd had any intellectual integrity (ha!) he’d have started out by looking for a genetic or epi-genetic basis for “handedness”. But he wouldn’t get all that sweet wingnut attention/funding.
Maybe some MLB funding, though.
In my case it was Mitch Hewer from Skins with his shirt off. Is that a viable biological explanation for homosexuality?
I look forward to hearing an epigenetic explanation for the pineapple-on-pizza dichotomy next…
I remember someone in the 70’s suggested imprinting during early childhood as a causal factor.
It is strange to see him acknowledge that without any candidate genes, it’s impossible to postulate a genetic cause for sexual orientation, and yet the complete absence of candidate epigenetic sites is somehow possibly explanatory. It’s even worse because epigenetics is all about modification of gene expression…so if there are no candidate genes for a given phenomenon, how can there be candidate epigenetics for it?
I suspect ‘epigenetic’ is taking some ground from ‘quantum’ as the go-to adjective for woo purveyors. Complex, not fully understood, and counter-intuitive: ideal for magical thinking.
Nicely said!
… hypothetical “epigenetic marks” …
Does that make Oldroyd a marks-ist?
Has anybody identified any specific mechanism(s) for epigenetic effects at all?
Well, the promotion of mutual aid, within some limits is a thing. Otherwise, humanity (by extension of precursor social species) would never have survived at least two extinction pulses.
But, I disagree that physics and chemistry are biased by biology, but the converse setting rough boundaries for biology is true. We’re not going to suddenly fully ionize any atom, well other than hydrogen and survive, physics and chemistry simply won’t find stability enough to continue life biological processes.
But, there are some biological clockwork processes involved, they have to do with signaling chemicals, structural elements and proteins and enzyme systems, with plenty of room for a wide spectrum of behavioral traits that are as heritable as my sweat socks. An observation supporting that is, our children inherit the same basic structures in their bodies via genetics, but behavior is shaped both by genetics in part, experience, environment and individual minor differences in everything from enzyme systems to receptor differences that are not heritable, they’re as you said, non-heritable traits accumulated by the messiness that is life.
Hence, a modest receptor change induced Grave’s disease in me, Hashimoto’s in my granddaughter. Both, within the scope of a modest mutation, either viral, environmental or random changes and both within the normal immune system responses to a receptor change (current leading theories are leaning toward viral for many cases).
But, there’s no single mutation of a gene for autoimmune disease, there’s no hyper or hypothyroidism single gene, it’s a wide assortment of genes that can give a predisposition and some people can have the full set of mutations and still never develop autoimmune disease.
Life isn’t a precision machine, it’s a rather messy, somewhat inefficient set of processes, where tolerances are at the molecular level quite wide, so that an SNP isn’t always awarded with cancer or just instant death. That modest inefficiency allows evolution to occur, adaptation growing easier in some environments by de novo traits acquired and more.
Because, he failed also in locking onto one sex hormone above all others, apparently testosterone is his root he chose as a taproot for his tree. That fails entirely to explain the entirety of sexual preference spectrum in vertebrate sexual selection.
And further falls apart in the chemistry, as he entirely ignores the processes involved in the creation of testosterone, passing progesterone and estradiol being part of those processes and overlap in the receptors for each being created.
As for his Mcguffin of epigenetics, yeah, that’s just wildly off. If one is going to try to support that, one must needs show at least a solid majority of instances where selection is due to measured epigenetic changes, which will never happen for the same reason there isn’t a gay gene or a third eye gene.
And ignores the fact that protein expression isn’t 100% efficient, a one-off molecule can allow a receptor or enzyme to still function and induce no measurable change in the cell or organism, as it’s only one receptor out of many thousands per cell.
My own view (and it must be right, since I thought up, right? :-) ) is kind of a mix of:
the systems we humans have (incl. the tendency toward societies, and to reproduce) are a product of random chance, so they have lots of glitches but work well enough often enough to keep the species going. They’re a bit Rube Goldberg. So it’s inevitable that there will be individuals who will diverge from our idealized view of “how it works.” BTW, I’ve read that this is seen in other species — same-sex matings among fruit flies, gay pairings among penguins.
species that survive robustly have a fair amount of genetic (and other) variation over their populations. This is my pet theory to explain the continued existence of neurodivergent people in human populations: neurotypical people keep societies going, but neurodivergent people are better at coming up with adaptations to things their society has not encountered before.
Gender is a social construct which varies a lot from society to society and over time. The same behavior that is seen as cross-gender in one society may be seen as normal in another. Plus, people’s behavior is heavily influenced by society’s constructs, which, at least in Western society, are heavily and violently policed, so people who might go one way or the other don’t even think of diverging from the behavior mandated by their society. (That was my case.)
Basically, at this point, I would take any theories that purport to explain sex-based or gender-based behavior with many, many grains of salt. Western notions of “how women are” and “how men are” are so deeply engrained in all of us that I would never trust that any scientist’s observations, theories, or research in these areas aren’t heavily biased by them.
If anyone really needs either an evo-psych or “epigenetic” explanation for gayness or any of the other sexual orientations/preferences we call “deviant,” I have one that I, for one, think is useful…
Humans have been social animals LOOOONG before we evolved our big cerebral cortices and became “thinking” or “rational” animals. This means early humans couldn’t form all their necessary social bonds/networks based on rational calculation, but had to do so based on instinct-based compulsions, longing, desires, that overrode all other feelings such as short-term self-preservation or plain laziness. We all acknowledge the instinct-based compulsion to find a “suitable” opposite-sex partner, have sex with said partner, make babies, and stay with said partner to form families in which to raise their babies with all the skills and strengths they need to thrive on their own.
But here’s a fact that all the heteronormative “nuclear family uber alles” authoritarians fail to grasp: that’s not the only kind of social bonding humans needed to form, ever. Parents need to love their children to the extent of sacrificing nearly everything for them as needed; and young children need to love and trust their parents and older siblings. Young men needed to work closely with each other to do brave and very dangerous things, like hunt big animals, fight off big predators, fight off aggressive neighboring tribes, and deal with storms and other dangerous events that require physical strength, bravery and cooperation. Young boys needed to look up to older men to learn what they needed to learn to become men in their turn; and men needed to take said boys under their wings and pass on their knowledge and experience. And all of those social bonds — and plenty more, this is clearly not a definitive list — are most likely to happen when humans feel a deep longing or compulsion to be with and work with the people they need to work with, and feel deep fulfilment when they succeed in doing so. And it’s inevitable that all of these instinctual longings will, at least occasionally, for better or worse, be expressed in sexual activity. I know this is very simplistic and probably over-generalized, but my basic point still stands. Does anyone really need any better explanation for non-heteronormative sexual attractions?
(Note that I am most certainly NOT condoning or justifying all forms of present-day sexual activity on these grounds. We’re capable of higher cognition and responsible thinking now, and we have a duty to understand that having the hots for someone, in any circumstances, doesn’t make it right to have sex with them.)
I look forward to hearing an epigenetic explanation for the pineapple-on-pizza dichotomy next…
Um…something to do with how the Italians adapted to Mongol invaders…?
The title of his book is Beyond DNA and he talks about epigenetics? Does he understand that epigenetics works by modifying DNA?
@9–
Yes, epigenetics has well established mechanisms as well as poorly understood mechanisms and almost certainly mechanisms as yet unidentified.
https://www.cdc.gov/genomics/disease/epigenetics.htm#:~:text=Epigenetics%20is%20the%20study%20of,body%20reads%20a%20DNA%20sequence.
More technical and on a specialised topic: https://clinicalepigeneticsjournal.biomedcentral.com/articles/10.1186/s13148-022-01382-9
…or, ya know, these idjits could just acknowledge that “preference in sexual partners” is inherently fluid and is only influenced, not determined, by intracellular factors. However strong that influence is, it’s easy to point to other strong influences that can be overcome by environmental factors like “nutrition” and “physical trauma” and “exposure to chemicals not even invented when the genome was set” (not to mention “Spider-Man-like exposure to radiation” and such!). And I’m making it easy by limiting “environmental factors” to those that have objectively verifiable biochemical/biophysical trigger points, without considering anything that’s primarily behavioral/perceptual in the environment.
One is reminded of the Michelson-Morley experiment — the purpose of which was to measure the speed of light in the ether. A fair and (certainly for the time) comprehensive look at the data, however, demonstrated not what the speed of light in the ether was, but that light was transmitted without an ether. So maybe the “determinist school”‘s efforts to determine the exact locus and mechanism of determinism as to “sexual partner preference” are just demonstrating that there is no determinism… not even as to the squicky types for whatever value of squicky might be at issue (intentionally or otherwise).
These guys want the equivalent of Bohr atoms — something discrete, and measurable, and above all without exceptions in how
electronspeople behave; but not a quantized universe in which even electrons have subcomponents that we can’t quite nail down yet, let alone exceptional behaviors based in part on volition. But we’ve learned an awful lot since the simplistic Bohr atom model was proposed, including incremental inching toward playing dice with the universe…Reginald@14–
Not all epigenetic effects involve altering DNA. Histone modification changes how tightly DNA winds around histone proteins, which can turn a gene ‘off’ or ‘on’ without affecting the DNA itself. Non-coding RNA is a booming subfield within genetics–it’s utterly astonishing the functions and complex feedback loops involving ncRNA, and most of its functions involve interacting with mRNA or proteins rather than DNA. ncRNA is amazing stuff that hasn’t really leaked into pop science media yet.
@2 rietpluim: It’s a good question. The glib answer is that male-female sex is necessary to produce offspring, but that runs into the problem that straight people are often interested in sex even at times when offspring aren’t possible. Most sex turns out to be non-reproductive. If it has a social role instead, maybe it’s just a historical artifact that we aren’t all bi? :/
So if one were to depict the ‘Creator’, a jar full of various dice (all weighted differently) might be the best way to do it?
@16–
Strictly speaking, the Michelson-Morley experiment didn’t completely rule out aether. Lorentz developed the concept of length contraction thinking he was rescuing aether theory. Ironically, his equation is now one of the standard formulae in special relativity. But yes, it’s definitely true that the MM experiment was the first big crack in the aether hypothesis.
@19 the creator also drops and loses the dice frequently or breaks off a corner.
chrislawson @ # 15 – Thanks! A very helpful beginners’ intro.
“My preferred explanation…”
As usual, someone else takes a bunch of thoughts I only vaguely comprehend and distill them into clarity in a way I very rarely can do.
(Envious anger 😡 )
“First in priority is cooperation, building a social environment that promotes mutual aid . . .” So gay people are an inevitable result of Christian Nationalists ands MAGA conservatives? Ha, I knew it!
“What makes them gay” could be worded as “what doesn’t make them hetro”.
Think of all the things that have to come together to end up with sexually inclined hetrosexuals with the appropriate genetals and a desire to have sex.
Evolution favours the whole package and has got good at it. It doesn’t always go there but the population cost is low.
@20 Michelson-Morley did rule out an aether that worked like what they thought they’d be measuring. It admittedly didn’t directly rule out the possibility of a different kind of aether as postulated by Lorentz, but my recollection is that the different kind wasn’t considered in the M-M experimental design, and the particular instrumentation would have been suboptimal for it.
The key point is that the assumptions behind an inquiry matter to the results achieved — and it takes a great deal of insight to question those assumptions after the experiment. The historical pathway toward ring-structured aromatic compounds in the mid-19th century is equally, and perhaps even more, revealing — but it requires a much deeper initial understanding of what we now “know” about electron sharing (and as a biochemist, it’s still, umm, “sexier” to talk about overturning an entire school of physics than of rather technical distinctions often apparent only in the lab after days-long reactions subject to lots and lots of lab-technique errors!). And I think I hear the ghost of Rosalind Franklin whispering something similar…
@17- chrislawson
Due to ENCODE and a shit-ton of confusion people might take ncRNA and much epigenetic rhetoric as meaning biologists were wrong about the extent of genomic junk. From Moran’s recent book I came away with an appreciation for spurious transcription and junk RNA. It may be a stretch to wonder about spurious translation and junk peptides…
As for the above mentioned mutual aid, I know this is a Kropotkin friendly zone and I’m not averse myself, but at base there’s probably an offsetting tension between egoism and altruism built in to our psychic structure. Mutual aid to the extent it has occurred has a dark side of ingroup preference, so isn’t entirely kumbaya. Not that I herald egoism either. Actually both egoism and mutual aid are susceptible to Hume’s guillotine or the popularized version of Moore’s fallacy if misconstrued.
@26–
Absolutely the MM experiment was a huge problem for aether theory, completely unexpected by Michaelson and Morley themselves and, as you say, incompatible with the prevailing version of aether theory. But it took quite a few other experiments (and not just MM replications) plus SR to kill it.
Neither Michaelson nor Morley considered it the end of aether theory, nor did most of their contemporaries. Michaelson was more aware of the challenge it posed and bluntly pointed out that the prevailing theory had to change. Morley could not accept that and spent years working with Dayton Miller looking for experiments that would support aether theory well into the SR era.
The traditionalists turned to ‘aether drag’ to explain the MM experiment. That is, the rotation of the Earth dragged aether with it, creating zero relative velocity between the experimental apparatus and the aether at Earth’s surface, similar to the way the atmosphere is dragged around with the Earth’s rotation which is why we don’t experience 1600 km/h winds. This is not a terrible idea, and was hinted at by Arago in 1810 and formalised by Fresnel in 1818, many years before the MM experiment i.e., the idea wasn’t a revisionist invention for the purpose of saving aether theory from MM. The idea still lives on in a way as frame-dragging, an effect predicted in GR and experimentally verified.
One of my favourite stories from the history of science: the experiment that put the nail in the aether-dragging coffin was Sagnac’s in 1913. Sagnac was convinced that his experiment validated aether theory, but he made errors in his assumptions and had unwittingly found strong evidence against aether dragging. His finding had been theoretically predicted by von Laue two years earlier using SR and was compatible with either SR or a stationary aether, but not with aether drag. Sagnac was not aware of von Laue’s work at the time. The problem as of 1913: to save aether theory from MM it was necessary to invoke dragging, but to save aether theory from the Sagnac effect it was necessary to reject dragging. And so, the end of aether theory (barring a tiny minority of physicists).
chrislawson @ 20, I remember discovering the Lorentz contraction in 7th grade by chance, finding it a fascinating concept, I incorporated it into the famous simplified E=MC^2, figuring out the significance immediately from the effects of the contraction. I then confirmed that full relationship with the advanced study text books that our junior high school library once held.
Frankly, the neatest thing since the invention of the Popsicle stick and overall, while earth shaking together, was essentially based entirely on old work, combined in novel ways, improving overall knowledge tremendously.
And given later historical knowledge, I credit his firth wife with much of that work, which would also explain where she got a tidy sum sufficient to pay for an entire apartment building, which interestingly dovetailed precisely with his Nobel Prize winnings.
birgerjohansson @ 23, “My preferred explanation is”, it’s PFM.
Pure Fucking Magic.
For those that know me, there’s a much longer explanation and theory, involving loads of technical factors, but uncertainty prohibits a certain explanation and I just really don’t want to go into it unnecessarily and bore those who have essentially arrived at the same conclusion to tears.
hemidactylus @ 27, spurious transcription was precisely one concept I was speaking of in my early comment. I just couldn’t recall the term. Hopefully, I’ll recall it next time, since it’s a concept I rarely have to express usually, but do prefer to retain.
As for Kropotkin, I’ll simply suggest that socialism is indeed a perfect social system, notable for its dearth of perfect individuals that exist to exist within that system. That said, I’d an excellent correction to deficits in other social/economic systems, when properly applied and balanced within a specific society.
I tend to be rather egalitarian in project leadership, preferring cooperation and teamwork via competitive ideas via discussion by shooting holes in ideas on how to accomplish a goal’s solution proposed, then fill the holes or suggest a superior solution, which will get its own holes shot through it, fairly quickly with a good team, that whole mess sorts itself out.
But, for those destructive, there’s my other management mode. I’m an absolute dick to work for, I’m the best guy in the universe to work with, don’t work for me when it’s far easier and less effortful to work with me.
That system’s worked quite well for me, because I don’t do that ego thing, accomplishing a common goal is what matters in my world. Solving the problem matters, creating new ones out of luminiferous aether doesn’t matter, “it won’t work” isn’t a factor, save if one then defines why it won’t work, finding prospective problems does matter and that’s the team goal. For some odd reason, people like working with me, as dick mode rarely gets expressed.
Two other rules, the working idea isn’t mine, it came from the originator, a member of THE team, not my team. My ideas won’t always be good, indeed, they likely will be lousy, let’s gin up a proper solution.
chrislawson @ 28, all invaluable contributions, for both nailing a coffin properly and well closed, as well as proving GR and SR as more correct than assuming that which does not exist does.
I do find attempts at resurrection of aether entertaining though, due to their massive errors in assumptions.
I suspect we’ll see a similar end to magic numbers, especially doubly magic numbers soon, since our experiments are now approaching levels that could reveal the math that resolves things without that joking reference far more finely.
And likely, even then, lithium will remain weird, awaiting a wee bit better math. ;)
For those confused by the lithium comment, lithium is weird. It’ll fission easily, it’ll even fuse somewhat easily, although nowhere as easily as some lighter isotopes. It fissions easily into tritium, hence why it’s used in the fusion stage as lithium-deuteride as the core of the fusion stage, fissioning into tritium, a neutron, to meet its cohabitant in space – deuterium, to be pressed together by the veritable hell ongoing outside to compress them, to fuse, releasing more neutrons and xray and gamma radiation (OK, massively Goobered down).
For an element that’s atomic number 3, just after helium. Fairly lengthy, but simple math later, termed doubly magic nucleus, but the math doesn’t have a fuller explanation. I suspect some relativistic effects and gluon number mismatch at such energies that will be better explained later, as our energy levels in experiments *and timing becomes much finer.
But, with a nick like Wizard, obviously I have fun with anything “magic”.
And well, while my applied calculus is beyond weak, my comprehension of application of energies and systems isn’t weak at all. Were both strong, I’d add my suggested equation to the shelf already overflowing with them.
Circling back to the Original Question, the author of the drivel suggested a very simple solution to a problem.
Stated empirically as E=MC^2, always and forever, Lorentz is not allowed and well, entirely misses the fucking target, largely due to frame dragging, due to the phenomenal mass of the bullshit needed to support the idiocy.
While, I cannot describe correctly a methyl group from an phenyl group, I do comprehend chemical families and their interactions. I also understand intimately interacting systems of systems. I recognize pharmaceutical families well enough to converse intelligently with pharmacologists, and indeed, I have.
And I do recognize bullshit.
And I do have a rather severe bullshit allergy.
Now, excuse me, had a molar shatter and cut a literal quarter inch hole in my tongue, walked to the market a couple of miles away and back and overall feel like shit and just got a notification of a geomagnetic storm that’ll likely destabilize my systems, due to an observed significant ground current nearby that’s caused other crashes.
Life can be annoying at times, but more annoying is the lack of life. Otherwise, my dead friends would be telling me all about how great death is. I only get that from the living and I suspect, they don’t have my best interests at heart.
And I really hope that this medical irritation set doesn’t send my ass back to the frigging hospital again.
His piece doesn’t mention bisexual people at all. Bisexuals outnumber us mono-sexual gays by about 3 times, so surely the behaviour you want to explain is that. Or at least acknowledge that most people who fuck people of the same gender also fuck people of other genders.
And if you look at rates of queerness by age it appears to be strongly influenced by social conditions. His whole analysis seems based more in heteronormativity rather than biology (another concept that doesn’t seem to turn up in the article)
OT
“Empty noise” ?
The team of God Awful Movies has dug up something very loud and very stupid – yet another vanity film project from the leader of the “Happy Science” cult.
Sadly, not quite as bad as the “documentary” about breatharians, who claim they don’t need food.
Or the film where someone claims water gets sad if you yell at it.
Dangerousbeans @ 30
If bisexuals outnumber “ordinary” gays, I am reminded of a very old joke, about having twice as many chances to score.
Using simplistic thinking, one might speculate being bisexual would be favoured by selection as it creates a wider social network. Alas, this is probably just another random quirk of nature.
The fixation on testosterone and gay men is very telling. It’s rehashed Everything You Always Wanted to Know About Sex (But Were Afraid to Ask). Gay men are gay because of a lack of testosterone. And I guess gay women are gay because of too much? Never mind the ridiculousness of such a claim. Gay panic comes in many forms. Othering gay men as something other than “men” is nothing new.
At least Reuben had the good sense to try and clean up the mess.
I assume gayness happens because of a hiccup in fetal development, and since gay people can have children there is no evolutionary pressure against said hiccups from happening.
There are a zillion chemical signals bouncing around (some coming from commensal organisms that have co-evolved with humans), untangling it all is a task that will continue a very long time.