Now, finally, it might surprise you to know that we largely agree with one another. The entire starting post cited the issues, origins and problems with creating female astartes and how they would offer little the overall setting. The final point you are so utterly bloody obsessed with was a suggestion, a minor conciliatory point to players who wished to have this and work around the canon, rather than bulldozing it and establish their own concepts within the broader universe. It was there in the same way as how I have previously argued elsewhere that there could exist sane and non-berserkery World Eaters, borderline xenophobic cadres cultivated by the Tau Empire for singular purposes, and other concepts which worm their way about the canon. It was not supposed to be some desk flipping "CHANGE IT, AND HERE'S WHY YOU SHOULD DO SO!" It was supposed to be an end to this entire damn argument once and for all. All you've succeeded in doing here was dragging it out further, and making me reconsider my position on this entirely.

After all, if you so vehemently oppose something built to directly avoid any canonical articles without disturbing established fact because they're of the opposite gender, perhaps their supporters might have a point after all.

Closest would be the Ke'lshan, who are seemingly under constant attack by xenos and therefore are quite xenophobic.

Actually that was more in reference to fan creations, but fair point. I previously argued with someone on how it would be justifiable for a Tau Empire to create an utterly xenophobic force intended to annihilate certain races wholesale, or learn exclusively how to murder other species rather than defend their homes, in the face of certain invasions. One example was basically turning one Tau Empire force into something akin to the Deathwatch, but devoted to experimenting upon and destroying Tyranid sub-species thanks to the damage the prior invasion inflicted.

They are Trans-Human, Post-Human, Meta-Human, or whatever label you want to apply for them being beyond normal humanity.
And they have been known to say that they gave up or sacrificed their humanity to gain the ability to fight humanity's enemies.

You do know that normal humans can be barrel chested.
And what are they barrel-chested in comparison to? Their own body or the normal human's?
It's not exactly clear on this point because of the perspective it is written from.

You did notice that the 'Lifesize' piece of art starts at 1 foot?

Isn't that an amalgamation of official GW artwork?

Please not the Phil Sibbering fan art! He did that by going from an altered silhouette of power armour without regarding the systems between the user and the armour layers. There are supposed to be power cables running round the ribcage front back to front! Bug ones like those you see on the stomach of most models.

Same with this one. But you must understand, the original GW art is based off the model and that is disproportionate in itself.

If by extended you mean the waistline expanded, then I disagree because not only does that not allow for the under-armour systems listed in power armours background, there's two layers of breastplate amour on Mk VII, it also doesn't fit all the artwork.
Like this piece from the Index Astartes article Rites Of Initiation.
http://redelf.narod.ru/p/w40k_ia_roi_4.jpg
http://redelf.narod.ru/w40k/ia/w40k_ia_roi.html

The differences between the female human skeleton and amale human skeleton may be minor when compared to a third skeleton from the animal kingdom, but in direct comparison to each other the differences aren't subtle.

Take a look.




Notice how the females skeletons lower leg bones have a shorter proportion to the rest of her skeleton than the same bones on the male skeleton. And it seems to be the same with the forearms.
The Pelvic bone is not only proportionately wider in the female, but the blades over the hips cover more of the joint.
The female ribcage not only has a proportionately wider gap between it and the pelvis, but has a different shape with its widest point sitting higher in the chest and the lower sets of ribs looping further down and more under the chest than the males.
The sternum is a different shape between the two, with both linking differently to the clavicles.
The female clavicle is also shorter helping the shoulders sit closer together than the male counterparts.
And the bones of the face are different between the two, with the male having more ridges and a wider jaw.

Quite a few of these bones are affected by the process to create a Space Marine, especially by the Ossmodula.
So they both get bigger skeletons, but the proportions remain. Plus their ribs become interlocked creating a solid mass on bone plates.

Yes androgynous builds do occur naturally.
Which is why I said that if you turn women into astartes they would have a range of physiques from the very feminine through to the practically androgynous.

Combat Drugs.
Chemicals that help in combat like, nootropics, speed enhancers, fuel for muscles, and probably something to reduce lactic acid in muscles.

Drugs that athletes take to enhance performance include anabolic steroids, human growth hormones, selective androgen receptor modulators (normally used for male hormone replacement therapy), amongst others.
https://en.wikipedia.org/wiki/Performance-enhancing_substance
There is crossover between the two but Astartes don't take Anabolic Steroids, growth hormones, or SARMs, as they don't need them. Their geneseed provides versions much better suited to them because it has been specifically tailored for the job.

To work in a womanyou would need similar substances but specifically tailored for female biochemistry.

After all the geneseed and implanted organs do utilise the processes of puberty to turn a boy into an Astartes.

Except the Ossmodula also binds Ceramic compounds to the bones of the skeleton to drastically increase strength of them.

Well I'm sorry to say that in my experience there comes a moment in these discussions where I am questioned over my knowledge on the subject. Sometimes my knowledge does fall short, yet generally I do know what I am talking about.

I am familiar with those works.
But still, altering memories is also fraught. Like in the Stargate SG-1 episode Collateral Damage.

But Molech was one campaign.

The lost Primarchs fought as part of the Great Crusade in multiple campaigns. One fought for Decades, the other for over a Century.
That means altering the memories of all those survivors who fought in those campaigns, the populations of the worlds they brought into compliance, and possibly even any surviving opponents (because you don't want some Warboss using them to troll the Imperium).
At what point does this become unfeasible for even the Emperor?

With Molech the Emperor had those whose memories he wanted to adjust in one place at the same time.
It would not be like that with adjusting memories of the lost Primarchs.

No. I am pointing out that the DNA used to create Russ had animal DNA in it, as described in Deliverance Lost.

Actually I am saying that the lego brick treatment is what those in favour of Female Astartes are suggesting. Primarch DNA is far more complex than normal human DNA.

Like I said, that is the Canis Helix. And we as yet have no explanation for how it works.

I discounted all that because truthfully we don't even know if the Primarchs have such Chromosones, or even if they are as limited in number and complexity as humanity's norm.

I still think it wouldn't work though.
(Sorry had to snip a few quotes to fit.)

40k has equality of oppression. The only privileges that exsist are the privilege of aristocracy or authority, and those are still very much "privileges" because any rights are only there for as long as is convenient to the upper echelons of power. The only isms that exsist are classism and elitism, as even xenophobia is leveled against actual xenos, ie other species. Of humans your race is irrelevant as long as it's not an abhuman/psyker, in which case those fictional races/subspecies do have extra oppression and persecution, which because it's fiction who cares/grimdark/everyone is fucked.

The fact that Astartes is a boys club is irrelevant, as just about any fan knows, as you have to willfully ignore nearly all the other factions. And I'll be the one to point out that there is the science part of science fiction. Of the established process of making children into Space Marines we know it's extraordinarily difficult on the body, you need to be in peak physical condition to have any chance of survival, and, well

I'm sure she's not actually the strongest woman, but the point remains. Despite what some choose to believe, women do not in fact have the same physical capacity as men. It's why professional sports are still segregated, it's why PE classes have different testing requirements, it's why the genders don't compete against eachother in the Olympics, go ahead, check the scores, you'll see a consistent difference

(2012)
So yes, besides biology there is a physical component as well that makes it plausible that the process that creates the roid monster of a meat machine Astarte would kill any woman they attempted the process on. They would require some sort of extra steps, injections, whatever to give them a chance of survival, and in 40k there's no gender based ideological drive to do that, they just want to make the strongest biological murder machine they can in the quickest, most efficient way possible.

and on the entire strength thing again.
the worlds strongest woman was able to lift around500 pounds (with is a huge lot)
But the worlds strongest man has been able to lift has lifted around 1000 pounds.

and as Dokta said, its just about of to efficiently make giant living weapons, and men are much more suitable candidates in far most cases.

its not a matter of if they can or anything ehwn genetic modification is on the table. The question is

"Is it ok to eradicate all of humanity and everything that makes us US just to appease political correctness." Once male and female space marines figure out they can breed due to genetic compatibility, us, the weaker forms of them will be replaced and or hunted down and killed. Its the way of nature. Rats and mice, Wolves and Dogs, Chimps and monkeys.

Space marines do not have the drive of what makes us human as well. They are completely content as they are. As such Mankind could never win against Homo Astartes in a special war.

Astartes are meant to safeguard humanity and act as their protector, not the tool of their destruction.

I should point out that there is no evidence that Astartes enhancements can be passed down to a subsequent generation via reproduction.

The one known instance of Astartes fathering children after becoming Astartes is old, and has questionable canonicity, but the offspring appeared to be normal humans.

It is possible that whatever genetic modification Astartes undergo does not effect the testis, and therefore cannot be passed on.

And if it could happen, you have to wonder why CSM aren't using it to produce semi-Astartes!

Becuase they don't have compatible female genestock. If Male Space marines can sire children with humans, then they would sire viable offspring with females of the same genus.

I'm just gonna reply to these, because you can't be bothered to google anything you say. An under 30 female's average time in the marathon doesn't eclipse the male's average time until the male is in the 60 and older group.

We're talking about a process that turns normal men into giant super freaks, and you're worried about a little extra estrogen floating around? The differences in biology between a male and female are there (although thats mostly due to the presence of Aromatase leading to a larger estrogen concentrations in women and reducing the amount of adrogens because androgens are used to make estrogen), but I don't see how the super advanced science of the Emprah wouldn't be able to simply hand wave it away (or just giving an aromatase inhibitor).

Shoot, the simplest genetic way for SM development in my mind would be the introduction of a retroviral that introduced the "geneseed" DNA into the hosts (which could easily be designed to suppress the Y chromosomes expression). These genetic changes would then be working on the exact same DNA template whether the initiate was male or female, and given the absolutely massive changes to physiology, I doubt you'd be able to tell if they started as male or female.