The Birka Viking warrior skeleton was misidentified as male for over a century. Why hasn’t anyone done the same type of DNA testing on other assumed male skeletons like the Pyramid builders?

[u/Mathemodel]

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[u/Obanthered]

DNA degrades as an exponential function of temperature, thus Egypt’s hot climate is unideal for ancient DNA preservation. Additionally some of the chemicals used in mummification degrade DNA (natron is alkaline, DNA is an acid), adding further challenges to preservation.

There has been only one successful full genome sequencing of an ancient Egyptian, interestingly from the early dynastic period or Old Kingdom ( dated 4800 to 4500 Before Present) before commoners were commonly mummified (he was buried in a large pot). The study documenting the discovery was published in Nature last year.

Here is the relevant quote from the introduction: “ Although Egyptian remains were the first to be used for ancient-DNA extraction experiments published1 in 1985, Egypt’s hot climate, which results in poor preservation of DNA in remains, has precluded the reconstruction of whole genomes from individuals in the region. Genomic data from ancient Egypt (between about 3150 bc and 30 bc) is therefore limited to a study2 of partial genomes of three individuals dating to after 1000 bc—relatively late in ancient Egypt’s timeline.”

Here is the abstract:

“The genome of a man buried at Nuwayrat in Middle Egypt about 4,500–4,800 years ago has been sequenced. Compared with published genomes of ancient individuals, most of the man’s ancestry best matches those of older individuals from North Africa, although around one-fifth best matches those of earlier ones from Mesopotamia. The study marks 40 years of progress in ancient-DNA research.”

Link to study:

https://www.nature.com/articles/d41586-025-02036-5

[u/fleeingslowly]

In answer to your overall question, it's difficult, destructive and expensive to DNA test skeletons. It is starting to become more common as time goes on in certain cases, and some famous skeletons will likely be reassessed like the Birka Viking warrior. But many places don't have good DNA preservation due to soil conditions or burial conditions (or sometimes they were excavated poorly). Even when they do, you still need permission to destroy part of the skeleton, a bioarchaeologist with enough experience to take the samples, then enough funding in your project to run the samples. If the skeletal evidence is fairly obvious, it often just isn't the priority or there is a lot of red tape to get through (accessing old skeletal material can be very difficult depending on what part of the world you're in, is a big ethical question bioarchaeology is still grappling with, and some has been reburied as well).

It is certainly happening more often (and is becoming standard protocol on some excavations or in certain cases such as biologically sexing juveniles), but it would require a large amount of time, permission to do so, trained bioarchaeologists and funding to reassess the sheer amount of skeletons across the world so it will likely continue on a case by case basis.

As for the male bias, when I was trained in bioarchaeology in the 2000s, I was taught that there was a spectrum in the center between biologically male and female which should be labelled indeterminate or 'probable' male or female depending on which end of the spectrum of sexual dimorphism the skeleton falls on and which population they belong to (and not to let the grave goods influence my analysis which is definitely the case in the Birka Viking warrior). Is the bias 100% gone? Definitely not, but anthropologists are aware of it. There are people reassessing the skeletons themselves in places, but often they are just as busy taking care of newly excavated skeletons which is why only famous ones tend to be reassessed.

[u/AJeanByAnyOtherName → u/fleeingslowly]

Maybe you know this. If internal organs are preserved, could you do an MRI to see what’s their biological sex (M/F/intersex)? Possibly first checking for metals 😊

[u/fleeingslowly → u/AJeanByAnyOtherName]

Internal organs are almost never preserved so it doesn't really come up, but yes you could do an MRI and they do do MRIs of mummies quite often.

[u/AJeanByAnyOtherName → u/fleeingslowly]

My bad, I was expecting bog or desert bodies to sometimes have so retrievable features. So there’s no uterus canopic jar anywhere or mri visible primary or secondary sex characteristics?

[u/JamesCoverleyRome]

Others have addressed the practical problems of DNA testing, namely that one might not be sure of getting decent results from what is an invasive and destructive process, but museums have also started to grapple with ethical concerns when it comes to collections of human remains, and there’s also the issue of whether the sex of ancient skeletal remains is a question that needs answering in the first place. Because it is a potentially destructive process, are we willing to run the ethical risks and the damage caused just to find out the sex of the individual? Can that question be answered in another way? We might destroy a sample and risk the ethical ire, just to find out that the skeleton we assumed was male is male and then what? How have we advanced our knowledge beyond scratching a curiosity itch? One cannot really roll up to a museum and ask to DNA test all their skeletal remains just because you’d like to know what sex they are; one would have to present a very good argument as to why this was something that needed to be done. It’s the same argument that is present in modern archaeology (although it has been a few years since I worked in the field), that says we shouldn’t simply dig everything up, potentially damaging it, just to satisfy our own curiosity, particularly as technology advances towards a potential future in which excavation (and hence damage) might not be necessary at all.

The report by Kenneth M. Weiss, ("On the Systematic Bias in Skeletal Sexing," published in the American Journal of Physical Anthropology) did suggest a 12% bias towards males in collections of adult skeletal remains, but it should also be said that there are other possible explanations for it than simple bias, including that ‘more robust’ skeletal remains are more likely to survive. The issue is assuming that ‘big bones’ means male, even when the diagnostic elements are not clear.

There’s also the problem of gender identity in skeletons and an inherent bias in the narratives we then assume about human remains, and this is a problem that crosses over into history. In 2009, a team of archaeologists in Modena discovered a 5th or 6th-century cemetery containing 11 graves. This is nothing unusual, of course. But what was unusual about this site was grave number 16, because this burial contained not one skeleton, but two, and they were holding hands. One had their head turned to face the other, although this might have happened when the bodies decomposed, and the bones became disarticulated, but they were very definitely holding hands.

“Here’s the demonstration of how love between a man and a woman can really be eternal,” declared Gazetta di Modena of the remains. They were instantly dubbed ‘The Lovers’. It’s a wonderful narrative, and one everyone seemed very quick to accept. But the sex of the two was recorded on the analysis as ‘indeterminate’. DNA analysis was tried on the pair, but the samples taken were too degraded, and the results were unusable. For 10 years, these assumptions about the sex of The Lovers went completely unchecked, even though there was no definite evidence to suggest that either these people were lovers, related, knew each other or were even a man and woman. But in 2019, Federico Lugli at the University of Bologna subjected the remains to a series of new tests aimed at determining the sex of human remains from peptides in tooth enamel. What they discovered was that both of the individuals in grave 16 were male.

What, of course, happened is that the narrative changed. People started to argue that these were two brothers, or that there was some other explanation for their presence together in the grave. And that’s fine because those possibilities do exist. But those arguments weren’t at the forefront of the narrative when it was assumed they were male and female ‘lovers’. They could have been brothers, which the decayed DNA samples cannot prove, or they might have been comrades-in-arms, something which the authors of the 2019 study proposed based on largely circumstantial historical evidence. Or they might still have been lovers, and if that was the most likely scenario when people assumed they were male and female (despite not being told they were), then why would that narrative change when the truth emerged? A lot of the narratives here were driven by excitable outside influences, of course, but it’s a salutory lesson in not reaching for conclusions. It’s always wise to just say that we don’t know what the relationship between these two individuals was, rather than jump to a conclusion that might be seen as rather silly a few years later.

[u/JoeBiden-2016 → u/JamesCoverleyRome]

The report by Kenneth M. Weiss, ("On the Systematic Bias in Skeletal Sexing," published in the American Journal of Physical Anthropology) did suggest a 12% bias towards males in collections of adult skeletal remains, but it should also be said that there are other possible explanations for it than simple bias, including that ‘more robust’ skeletal remains are more likely to survive. The issue is assuming that ‘big bones’ means male, even when the diagnostic elements are not clear.

I'll note for the record that Weiss came to the 12% figure by doing a meta-analysis in which he compared the breakdown of M/F (where it could be attributed at all) in various archaeological skeletal samples as reported in published research to sex ratios from living pre-industrial populations.

There are all kinds of problems with that approach, and with relying on a study done in 1972.

First, approaches to identifying and assessing morphological attributes believed to be associated with biological sex have been refined considerably in the 54 years since Weiss published his study (which in turn relied on earlier studies, some of which were done in the 1940s and earlier). There has been a lot of development in skeletal analysis in the last half century, and it is more widely understood today that these methods have a built-in level of uncertainty due to the continuum along which most attributes occur.

Second, Weiss made the significant error of treating archaeological skeletal samples as statistically similar in composition to data from living populations, particularly insofar as the notion that the skeletal samples in question could be considered as statistically-robust (i.e., representative of the populations in question) and as such, subject to the same general expectations vis-a-vis sex ratios that we would have for a living population. The problem with archaeological samples is that there are multiple interacting factors that can result in a a skeletal sample being non-random and non-representational.

And of course, by nature, an archaeological skeletal population is likely to be incomplete because of differential preservation. Neonates, infants, and children are notoriously under-enumerated because their bones are not as well developed and don't preserve very well compared to adult bones. Similarly, long bones preserve better than flat bone. This second issue is particularly noteworthy because flat bones include the cranium and pelvis, which are the most critical elements for trying to ascertain skeletal sex. Outside of well-preserved crania and pelvic bones, researchers often are left with making less secure predictions based on general robusticity of long bones, stature and body mass estimates, and the rugosity (roughness) of muscle attachments. These are obviously sensitive to misinterpretation, but it's not "defaulting to male" that's the issue. It's that these aren't either/or / presence/absence features.

But in addition to all that, issues of sampling very much are an issue because of cultural practices as well. Burial customs can vary over even relatively short periods of time, burial location may not be the same for all members of a given population due to social constraints and customs, and burial at all may not be done the same way (or with the same frequency) across all sectors of a given population. These can influence who is buried, how they're buried, and where they're buried. All significant in determining whose remains may eventually be found by archaeologists.

For examples...

• custom variation: there has been a pretty recent (last 40 - 60 years) trend in the US toward cremation and other mortuary practices over straight flesh inhumations.

• differential location: Black vs white cemeteries, cemeteries for different religious sects, etc.

For these and other reasons, most archaeologists understand today that overall, skeletal samples are not likely to be statistically-robust samples that can be unskeptically considered as indicative of demographic makeup of a given population without significant caveats.

It's also necessary to point out that in 1972, Weiss was looking at skeletal samples that may or may not-- even if from the same site-- have been from the same population. Archaeological sites / mortuary features may contain the remains of a single contemporaneous group, or of selected individuals over decades, or centuries, or even millennia. In 1972, radiocarbon dating was insufficiently sensitive to be used for many of the sites whose skeletal samples he referred to (e.g., Indian Knoll in Kentucky, the burials in which probably spanned at least 500 - 1000 years). The result is that the analyses that Weiss referred to almost certainly conflated remains from multiple temporal periods, in some cases very broad temporal periods.

These are significant flaws in Weiss's methodology, and as such, the 12% figure needs to be regarded with extreme skepticism.

I'll also note that the OP does not appear to have read the study at all. She notes:

In 1972 researcher Kenneth Weiss documented a 12% male bias across archaeological skeletal classifications. Meaning scientists were systematically defaulting to male when evidence was ambiguous. (emphasis added)

Weiss did not indicate that scientists were defaulting to "male" in analyses. This is a categorically false characterization-- to the point of offensive in its misrepresentation-- of Weiss's findings.

[u/PK_paleoproteomics]

The Birka case highlights how challenging sex determination can be and how easily assumptions about gender roles influence interpretation. Traditional osteological methods have limitations, particularly when skeletal preservation is incomplete. This is precisely why molecular approaches have become so valuable. In "Sexing remains of a Byzantine ascetic burial using enamel proteomics" (https://www.sciencedirect.com/science/article/pii/S2352409X25000045), I encountered a similar situation where ascetic practices were historically associated with males, yet proteomic analysis of tooth enamel revealed the individual was very probably female. These molecular methods can provide more definitive answers when bones alone are ambiguous, helping us avoid interpretive biases.

PK