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Let's cure sexual dimorphism!
July 1, 2014 7:14 PM   Subscribe

How would scientific folks go about making women biologically around the same size and strength as men?

To quote from a book I mentioned in another thread:

"A few hundred thousand years ago, men used to be one and half times the size of females, so our current 20 percent difference represents a distinct decrease. If we give it another couple of hundred thousand years, we may find that men and women match each other exactly and live in perfect monogamous bliss."

Is it even remotely possible to make women equally as strong as men someday? How would scientists work on solving this problem sooner than waiting through hundreds of thousands of years of evolution? What avenues of research would one pursue? What is there that could be tried?

I just got a cool fiction idea and I am trying to come up with a remotely plausible way to carry it out. Though it may be so impossible that I may just have to make it a fantasy rather than sci-fi....
posted by jenfullmoon to Science & Nature (32 answers total) 5 users marked this as a favorite
 
The short science fictional way would be to identify the genes in the Y chromosome that make men bigger, I imagine, and turn them off.

The longer, not fictional at all way, would be to encourage tall women and short men to have more children, thus counteracting the original evolutionary cost to being a small guy.

Or you could just wait. Sexual dimorphism arises when men compete physically for women. If the big guys get more women, and have more babies, then their genes will become more common. Since women are not beating up on each other physically, there's no evolutionary advantage to being big. So their genes optimize for other things.

Which means that since the dawn of civilization, size dimorphism has been going out of style. Rich guys have more babies, but big guys aren't always rich and rich guys aren't always big. Probably as a species we're now optimizing for wit and sexiness. That will tend to reduce sexual dimorphism over time.
posted by musofire at 7:24 PM on July 1 [2 favorites]


Well, you could give women testosterone and HGH shots during puberty... It worked pretty well for the USSR's athletes. Does have some pretty serious health consequences later in life though.
posted by miyabo at 7:42 PM on July 1 [2 favorites]


Part of it is going to be conditioning - so those studies about how newborns and infants and toddlers are treated differently according to gender can be extrapolated to its effect on how those children then use their bodies. So from birth, absolute equality in treatment (which doesn't happen now, regardless of what people actually insist when asked).

Then, social conditioning about strength - activity but also things like squat vs bench being a measurement of 'strong'.

So there are a few Aussie female athletes who have made enormous differences to their times by adopting men's training schemes. Not to the men's standards, but certainly far beyond the original standards. Which is a combo of both - families that are prioritising and pushing sport/athletics from an early age + adult conditioning about strength. And maybe drugs but the last scandal was for stilnox not steroids/HGH).

(I'm finding very little to back up the 'one and a half times bigger 100 000 years ago' - everything I am finding says 'moderate dimorphism' which is in line with current humans).
posted by geek anachronism at 8:00 PM on July 1 [2 favorites]


They already are.

Done and done!

In all seriousness, the average heights for both sexes are only a couple of inches apart. Weights also overlap significantly. (I could totally take a few of my male coworkers, and I'm on the small side for a woman.)
posted by Sara C. at 8:15 PM on July 1 [4 favorites]


There are a number of possibilities, but it would depend on a number of factors. First, women have a higher percentage of body fat compared to a similarly built and sized man. Also, there are differences in the bone structure (especially the hips) that are necessary for childbirth. Because of this (and, well, breasts), certain exercises are less efficient for females. While these are things to consider that would need to be dealt with, my question is, "Would you remove childbirth from the equation?". If in utero birth was not necessary, you could change a number of structural features.

Either that, or you could give men the same physical structure as women.
posted by Gneisskate at 8:16 PM on July 1 [2 favorites]


If the science fiction setting had the magical "artificial gravity" technology like in Star Trek and most science fiction film and TV, whatever controls it could just set the gravity in the immediate vicinity of every woman to be slightly higher most of the time, but equalized whenever men and women compete or interact for a "John Carter of Mars" effect. In space, with rotating space stations and rotating space ships to create artificial gravity, men and women could be segregated into different living quarters that rotate at different speeds.

In the absence of artificial gravity, maybe wrist and ankle weights people wear all the time?
posted by XMLicious at 8:21 PM on July 1


Rich guys have more babies, but big guys aren't always rich and rich guys aren't always big. Probably as a species we're now optimizing for wit and sexiness.

I don't think this is very accurate. For instance, the average male CEO is a few inches taller than the average man. (Wikipedia.)
posted by John Cohen at 8:31 PM on July 1 [2 favorites]


I think you'd have more luck with making men weaker, honestly.

Male hormones, as far as I know, provide a real advantage in strength, both in how strong/big you are out of the gate, and how strong (maybe less on the "big" thing here) you are as a result of physical training. I guess, on a scifi level...?

Well, you could engineer an artificial hormone cocktail that through magi-science hit all the things you're looking for (strength, size, speed) and doesn't hit the things that you presumably aren't (cardiac stress, body hair, acne, and emotional shifts).

As far as making men weaker, you could do the same thing, in reverse, which I think in real life would be easier as well. But the men you ended up with would be a lot less man-ish than the ones you have today.

Outside of eugenics, the only other solution would be widespread gene therapy before puberty, presuming that you somehow found a magic bullet combination of genes that could be expressed through X chromosomes that made women's muscles as naturally dense, etc as men's. And you'd still want to follow that up with magic hormones.

It's a very difficult question, at least for me, because it's hard to imagine answering it without really scrambling a lot of practical things that make men and woman what they are. If you were comfortable with having two types of men, one with a uterus and one without, then things seem a lot more doable.
posted by Poppa Bear at 8:31 PM on July 1


Eliminate men or women.
posted by rr at 8:37 PM on July 1 [2 favorites]


There's a lot of bad evo bio up in here.

Is it even remotely possible to make women equally as strong as men someday?

But to answer this question the answer is almost certainly not without getting rid of the sexes all together. If we are talking far future I think that's a more likely outcome than men and women of equal size and strength. Because the very things which lead to the sexual dimorphism (like varying testosterone levels) are what lead to the broad categories which we call "men" and "women".

I, too, would like some evidence that sexual dimorphism was much larger 100,000 years ago before accepting such a claim. The guy who wrote the quote is not an anthropologist or a biologist he has an M.A. in American History. So I'm not sure he isn't just pulling that number from the department of internet numbers.
posted by Justinian at 9:05 PM on July 1 [5 favorites]


You should probably just make it very soft sci-fi. If you just wave your hands and move on with the story, nobody will bat an eye.

If you're looking for realistic methods, it's probably be more realistic to accept the underlying biology and design a world whose norms prevented men from fulfilling the potential of their biology. So the ideal of masculine beauty would be a slim runner's build and the ideal of feminine beauty would be as tall and strong as possible. Little boys would be teased for showing interest in sports; little girls would be pressured to join the football team. Parents would push food on their girls and tell their boys to watch their weight. If there were such a thing as men's Olympics, it would be underfunded and its athletes would be largely ostracized for being freakishly big and unpleasingly callused, etc.
posted by d. z. wang at 10:00 PM on July 1 [6 favorites]


Sara C.: In all seriousness, the average heights for both sexes are only a couple of inches apart. Weights also overlap significantly. (I could totally take a few of my male coworkers, and I'm on the small side for a woman.)

Your suggestion blithely ignores the fact that men statistically range much taller, stronger, and faster than women (with both higher mean values, and higher record values). Furthermore, aside from this self-flattering take, even you are probably aware that, "a few coworkers" aside, in a fight for survival the odds favor the average man over "a small woman".

--

So, jenfullmoon, testosterone and other hormonal supplements during puberty have essentially achieved just that. Instead of hand-waving some other drug, why not simply hand-wave the worst of the side effects? Menses are affected, but reproductive drugs can enable fertility on command, etc...
posted by IAmBroom at 10:07 PM on July 1 [5 favorites]


The big difference is the pelvis, and the reason a man's pelvis is different from a woman's is the birth canal. Men's bone structure is optimized for strength and speed; a woman's bone structure is a compromise between strength/speed and surviving child birth.

So the first thing you do is redirect the birth canal so it doesn't pass through the pelvis. Then you can make a woman's pelvis the same size and shape as a man's.

A different problem for the strength-to-weight ratio is that women carry a lot of extra poundage required for pregnancy, childbirth, and for feeding babies. No matter what you do elsewhere in the design that's all dead weight when you're concerned with things like running, climbing, and fighting.

The only equivalent mass in a man is the testicles and the penis, which probably weigh a tenth of a kilo. I don't really know what you can do about that.

As mentioned above, the easiest way to get what you want is to cripple men, not to redesign women. It's a lot easier to make something weaker than to make someting stronger.
posted by Chocolate Pickle at 10:09 PM on July 1 [1 favorite]


This thread (and several other comments and your interest in fiction/sci-fi about the topic) is making me think of Kurt Vonnegut Jr.'s Harrison Bergeron. Read it, it's very short.

To question your premise, you may also be interested in Collette Dowling's book "The Frailty Myth", which I found slightly dated but still very relevant and quite interesting and inspirational. It's what finally convinced me that strength training and physical activity were not only good priorities for health, but actively feminist things to do.
posted by spelunkingplato at 10:28 PM on July 1 [3 favorites]


To add a further blurb for "The Frailty Myth," a quote from the inside flap: "Yet as breakthroughs among elite women athletes grow more and more astounding, it begins to appear that strength and physical skill--for all women--is only a matter of learning and training. Men don't have a monopoly on physical prowess; when women and men are matched in size and level of training, the strength gap closes. In some areas, women are actually equipped to outperform men, due partly to differences in body structure, and partly to the newly discovered strengthening benefits of estrogen." A really interesting read.
posted by spelunkingplato at 10:31 PM on July 1 [3 favorites]


"How would scientific folks go about making women biologically around the same size and strength as men?"

Sci-Fi I might look at species where the female is bigger than the male and use gene therapy as the tool.

"Is it even remotely possible to make women equally as strong as men someday?"

Sure, stong women breed with [on average] physically weaker men.

Shit, take a look at what selective breeding has done to dogs in the last couple thousand years.
posted by vapidave at 10:57 PM on July 1 [1 favorite]


A few ideas:

If you're happy to forgo a few morals, either kill or castrate all males who are stronger/taller than a predefined amount before reproduction, and evolution should take care of the rest in a few generations. Or, malnourish all males to prevent them from reaching their physical potential. You'll have to keep doing this indefinitely.

Otherwise, would it be possible to artificially augment human physiology in such a way that it levels the playing field? Either by putting a few bits of FutureTechTM in women and not in men, or by putting both in some kind of powered exoskeleton which gives both enhanced and equal physical prowess.

Or, change the evolutionary pressures, maybe in the far future it's an advantage not to be physically big, as you can't crawl through spacestations / radiation shelters / unobtanioum mines as well, or maybe a long healthy life / intellegence is selected for so the dimorphism slowly disappears, or maybe tall or muscular people suffer more broken bones and injuries as bone density drops in reduced gravity.

Finally, could you make a new, 'island' society on Alpha Centuri or wherever, and for technical ease, all of the initial passengers on the ark ship were pretty much physically homogenous, so their descendents have very little variation in height or strength.
posted by Ned G at 4:08 AM on July 2 [2 favorites]


I take this to be a near-future sci-fi story? If so, here's one way to achieve the desired results:

- genetic engineering has gotten way better, you can approximately customize your children to order
- while we're at it, these mods are inherited
- childbirth is passe, embryos are raised in vitro, so there's no impediment to narrowing women's pelvises
- taste dictates slim, althletic builds for both sexes

and, poof, everyone looks the same, sort of like haut coture models.
posted by mr vino at 5:37 AM on July 2 [2 favorites]


You have to figure out how to take childbirth responsibility off the table. If you can do childbirth in a completely artificial setting, like a room full of natal incubators, or if you specialize your society such that a specific group of women are designed to be the breeders, you can free up the other women to become strong competitors to men. You can still get the strong genes passed along by choosing the optimal egg/sperm combinations and then implanting them in the incubators or breeding stock.

It doesn't have to be creepy and gross - your society could have reverence for the breeders and hold them in the highest esteem. That could work whether they are human or mechanical.
posted by CathyG at 6:38 AM on July 2 [1 favorite]


Humans been making women (and men) bigger and stronger with science for the better part of a century now. The answer is to begin administering a cocktail of anabolic–androgenic steroids from an early age.

Although men on a similar drug regimen will still have a physical advantage on average, so if your intention is to erase the gap that could present a stumbling block. But maybe that isn't allowed in your future society. Anyway, if I were you I would focus my research on performance-enhancing drugs, which you should be able to find plenty of information about with a little digging.
posted by ludwig_van at 8:00 AM on July 2 [1 favorite]


How serious/satirical/hard sci-if is your story? A pill that "enhanced" certain areas of the male physique with the trade off of limiting height could be used for some humorous social commentary. And it provides a reason without requiring a technical physiological explanation.
posted by Benjy at 8:47 AM on July 2 [1 favorite]


> kill or castrate all males who are stronger/taller than a predefined amount before reproduction

Don't change the hormonal, body fat and skeletal differences, but compensate for them by breeding for women large enough and men small enough that they are equal in strength & speed given equal training regimens. Or make the men smoke tobacco.
posted by morganw at 9:27 AM on July 2


I just got a cool fiction idea and I am trying to come up with a remotely plausible way to carry it out.

This is an important point - How important is the process to the story? In other words, is this a story about how dimorphism gets eliminated, or does it just happen to take place in a world where that has happened?

If the latter, you don't need a plausible way to do it. You can just start the story in a world where dimorphism has been eliminated, and maybe toss off a couple sentences here and there referring to the event in which it happened.

If I had to spitball something, I'd say maybe something like a designer virus that alters the carrier's DNA and causes their children to be the same size (on average) whether male or female. Unless your story is about the scientists who did it, most people in it will only have a layman's understanding of what actually happened. Or, hell, maybe the virus just shows up - maybe crude life is found in space and it carries the virus, or maybe some previously undiscovered deep-sea life carries it. It doesn't matter much - your explanation doesn't even need to be plausible, it just has to be believable.

The latter two options would also free you from having to explain why scientists would do something like this, since it would be unethical, to put it very mildly.

Consider Jurassic Park (I know this is true in the movie at least, the book I'm not sure about): The writers couldn't think of a plausible way from having sequenced dinosaur DNA to having actual dino eggs, so they just kind of skipped that part, and no one in the audience noticed. Writing sci-fi is often as much about sleight of hand as anything else.
posted by FAMOUS MONSTER at 9:43 AM on July 2 [1 favorite]


I don't understand the solution of eliminating taller men from the breeding pool. Don't kids get their height genes from both parents? It's not like girls get height from their mothers and boys from their fathers. A tall woman/short man match seems like it would be just as likely to produce shorter girls and taller boys as to produce shorter boys and taller girls.

If science can pin down where height information is is stored and how it's processed in DNA, then I guess you could do genetic manipulation either one embryo at a time or possibly en masse for the parents, depending on the level of sci-fi/intervention desirable. I guess it wouldn't have to be just height, you could also get at the genes for everything else that contributes to strength (bone density? muscle mass? metabolism?)
posted by Salamandrous at 10:07 AM on July 2 [1 favorite]


I don't understand the solution of eliminating taller men from the breeding pool. Don't kids get their height genes from both parents?

Yes, so that approach would take thousands of generations to be effective.
posted by Chocolate Pickle at 7:13 PM on July 2


I suppose you could limit anyone over a certain height (probably 5'8/5'9 or so?) from reproducing, quickly creating a generation of children of moderate height.

However, height is also a matter of nutrition, and in fact part of me wonders if that's not one component of men being taller than women: boys are encouraged to eat a lot, especially during puberty, while that's exactly the point at which girls start facing a lot of pressure to conform to gendered eating habits. Yet another way that more equality between the sexes would probably result in a society where men and women looked more similar to each other.
posted by Sara C. at 7:17 PM on July 2


How important is the process to the story? In other words, is this a story about how dimorphism gets eliminated, or does it just happen to take place in a world where that has happened?

Sort of both? The story takes place on a few islands, one of which is our typical patriarchy society and another of which is an offshoot from there. Island B's residents figured out around 100-ish years ago that certain plants or something combined to change the sexual dimorphism of ladies (not men), so everyone on Island B is of equal size and strength. This has helped to detract Island A from say, attacking them. However, Island B's supply of mystery drug plants (or whatever) is suddenly gone, forcing them to make some kind of alliance with Island A that still has the plants so they can continue to make strong women in the future.

I guess I'll just have to go with handwavium because I sadly don't think anything IRL is really fitting with that after reading this. Bummer, I was hoping to be all Mira Grant and be able to base it on real science. I guess it's just not ever doable, really. Darn it.
posted by jenfullmoon at 3:33 PM on July 3


A more disagreeable solution but for the component of height and strength that is genetically-based, if you had an in-utero or sex cell test to predict a person's height and strength you could use the same sort of approach as in sex selection to ensure that the distribution of heights and strength among women who are born is the same as among men. As a plot device that might be more amenable to something unforeseen or beyond the control of Island B disrupting whatever medical procedure they use for doing it.
posted by XMLicious at 4:04 PM on July 3


I guess it's just not ever doable, really.

I'm confused. Is your requirement that the technological intervention take place prior to birth? Because growth hormone injections during puberty are a current-day, proven treatment for increasing adult height, with additional benefits in strength. And if you want to see the extent of muscularity attainable by women on a full cocktail of anabolic compounds, look at modern competitors in the bodybuilding division of the Ms. Olympia contest. Drugs could close the strength gap between men and women if only women are using them.
posted by ludwig_van at 9:19 AM on July 4


Women would have to be required to use performance enhancing drugs while men would be forbidden. That would close the gap in average strength though there would still be men who were stronger than the strongest women. But it would change the averages considerably.
posted by Justinian at 1:12 PM on July 4


Island B's residents figured out around 100-ish years ago that certain plants or something combined to change the sexual dimorphism of ladies (not men), so everyone on Island B is of equal size and strength. This has helped to detract Island A from say, attacking them. However, Island B's supply of mystery drug plants (or whatever) is suddenly gone, forcing them to make some kind of alliance with Island A that still has the plants so they can continue to make strong women in the future.

The place where my suspension of disbelief would wind up hinging with this idea is that evening out the average physiological difference between men and women in order to provide a military advantage would really only start to yield significant results in a society where a large majority of the population was already spending professional-athlete levels of time in strength training, and one where military combat was exclusively or almost-exclusively hand-to-hand. So there needs to be (1) a convincing reason why Island B is nearly perpetually at war with Island A and/or other parties, (2) a convincing reason why Island B hasn't developed projectile weapons, (3) I assume that your reason for why Island A hasn't adopted the same strategy is patriarchal norms, but then there needs to be a reason why Island B didn't wipe them out when they started to improve the strength of about 50% of their fighting force (maybe Island B has a smaller population to begin with)

I would technobabble the plants as actually "working" (in the sense of promoting strength, endurance, etc.) for both men and women, but having catastrophic side effects in men only--maybe due to a interactions with existing hormonal balances, or some sort of Y-chromosome linked effect.
posted by kagredon at 9:33 AM on July 9 [1 favorite]


(Maybe both sides used to use the drug/plant/etc. on their soldiers, but only Island B had female soldiers, so only they realized that women didn't experience the side effects, and it's now banned on Island A? Or--if you wanted to make a really dark point about how patriarchy intersects with class--maybe it's still used, but only for a special "Bruiser Corps", who are basically guaranteed an early and painful death, but are compensated well, and so still draw in plenty of volunteers from the destitute and desperate.)
posted by kagredon at 12:39 PM on July 9


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