Sex is a spectrum

Agustín Fuentes has published a new book, Sex is a Spectrum: The Biological Limits of the Binary. I just started reading it last night — and it’s very good so far — so don’t expect a full review just yet, but El Pais has published an interview with Fuentes in which he discusses the main themes. As you might guess from the title, he’s rejecting the idea that sex is a binary, and further, that the general implications of sex are not reducible. He’s an anti-Coyne. He’s also strongly advocating for a view of organisms that incorporates environmental factors beyond naked genetics.

Q. You assert that sex is a biocultural issue… but many of the people reading this interview will think that sex is about biology, not culture.

A. That depends on how you define “sex.” If you’re speaking only about gametes, everyone understands that [an] egg isn’t a woman and [a] sperm isn’t a man. We have to rethink a little about what we’re talking about. Just think about our feet, which are biological traits. But at the same time, look at your foot and look at the foot of a person who has never worn shoes. The two are almost distinct: the structure of the bones, the muscles and the skin changes. When I discuss sociocultural contexts, we’re talking not only about the embodiment of culture, but the mutual exchanges between experience, perception, bones, muscles, digestive systems, vascular systems… there’s a lot of interconnection between our physical body and the world and the experiences we have. There’s always more intermingling and a bit more complexity.

One of the unfortunate consequences of the Mendelian revelation is that we’ve swung way too far the other way, treating the individual as nothing more than the combinatorial action of a set of genes. Development is a critical and complicated input in generating the information that makes up the individual!

Then he gets into a point I’ve made multiple times before: there are so many distinct criteria that are used to identify a human’s sex, so just the fact that there are multiple independent measures refutes the claim that there is one pure definitive definition.

Q. You write about how the concept of “sex at birth” isn’t very rigorous, because it can mean many different things. You talk about the “three Gs.”

A. In the biological context, we’re talking about typical categorizations based on three factors: genes, gonads and genitals: the three Gs. A 3G woman would be one who has ovaries, clitoris/vagina/labia, and XX chromosomes. And a 3G man would be one who has testicles, penis/scrotum and XY chromosomes.

The importance of using 3G is the range of variation: it’s a spectrum that has standard groupings. We assume that, by looking at the genitals, you’re sure to have the other two Gs. And it’s true that they’re highly correlated, but not absolutely correlated, not 100%. We must understand, biologically, that these categories don’t contain all the variation in human beings; there’s variation beyond that. And, among the 3Gs, there are people – more than we think – in whom one of those Gs is a little different. If we use only the genitals at birth, or the chromosomes or the genes, we’re leaving out a lot of extremely relevant information.

I agree, except I’d suggest that there are more than three factors used. Some people claim that behavior is a factor in defining sex — true women, as we all know, are submissive, while men are dominant and aggressive. We can pile up all sorts of stereotypes and associations and none of them are going to be universal.

Q. This 3G explanation doesn’t reflect the biological reality of 1% of humanity, as you state in the book, which is at least 80 million people. But if it reflects that of the 99%, so isn’t it natural for many people to say, “Well, 99% is almost binary, isn’t it?”

A. But what is binary? I’m not saying there aren’t things that are binary in human beings. Gametes are binary: sperm and eggs. But saying that human beings are binary is a failure. It limits us too much when we’re thinking about the full range of variation between human beings. A binary relationship is that of one and zero. They’re completely distinct. This concept is used in computer science, because there’s no overlap in any element: either you have a one, or you have a zero. But human beings – our bodies, our ways of being – aren’t like that. There’s nothing between men and women that makes them totally different, like one and zero, because they come from biological materials that overlap on that spectrum of variation in our bodies.

To say that we’re binary is philosophy. It’s not biology. It’s declaring oneself essentialist: there are [men and women], two types of humans. But our biology doesn’t validate that position. Yes, there are binary things in our biology, but to say that human beings come in two different types is false. And we can prove it. Genitals, hormones, brains, organs… when you understand the range of variation between our bodies, it becomes very clear that human beings don’t come in binary, but in typical sets.

“Almost binary” — how can anyone say that with a straight face? The word “almost” refutes the claim.

Q. Is this an attempt to invoke science to justify a model for people? A model for society and a model for women?

A. Trump isn’t using science; all of his executive orders are a total scientific failure. Science – by pointing out the range of biological variation in human beings – shows us that there are indeed several ways to be human. And that’s the important thing. In any country, in any culture, there’s a range in bodies and sexualities, but our cultures, our governments, diminish the possibilities of expressing [ourselves] and living within that range. We’re always on an average; we’re bits and pieces of the full range of human beings. And the main thing is to at least know what the possibilities of that range are… to understand that this is what being human is all about: variation, not a standard.

Our culture is always controlling where we can express ourselves. We’re biocultural organisms: there’s always a greater range of variation than what’s culturally accepted. And that’s the difficult part. Because many people are certain that “this is a woman and this is a man.” But if they start thinking, “My cousin has a slightly different body,” they then realize that there’s greater variation. We all know people who are outside the typical categorization, be it behaviorally or biologically, of what we think women and men are.

Wait — he didn’t answer the question! Should we have a different model for society, men, and women? I’d say yes, and I can see how Fuentes is addressing an implied point, by bringing up Trump’s anti-scientific attempts to impose a rigid binary structure on America. It is the scientist’s role to explain how our preconceptions about the universe are contradicted by nature, and the narrow perspective of conservatives is flatly wrong, and therefore is a bad foundation for building social policy.

Fuentes for president! He’s American-born, so he qualifies, but he “wants to regain Spanish citizenship for fear of the political degradation in the United States,” so I’d worry that he’s going to be part of the flight of intellectuals from the US.

My first recipe from a Neandertal cookbook

I’ve taught human physiology, so I already knew about the limits of protein consumption: if you rely too much on consuming lean protein, you reach a point where your body can’t cope with all the nitrogen. Here’s a good, succinct explanation of the phenomenon of “rabbit starvation.”

Fat, especially within-bone lipids, is a crucial resource for hunter-gatherers in most environments, becoming increasingly vital among foragers whose diet is based heavily on animal foods, whether seasonally or throughout the year. When subsisting largely on animal foods, a forager’s total daily protein intake is limited to not more than about 5 g/kg of body weight by the capacity of liver enzymes to deaminize the protein and excrete the excess nitrogen. For hunter-gatherers (including Neanderthals), with body weights typically falling between 50 and 80 kg, the upper dietary protein limit is about 300 g/day or just 1200 kcal, a food intake far short of a forager’s daily energy needs. The remaining calories must come from a nonprotein source, either fat or carbohydrate. Sustained protein intakes above ~300 g can lead to a debilitating, even lethal, condition known to early explorers as “rabbit starvation.” For mobile foragers, obtaining fat can become a life-sustaining necessity during periods when carbohydrates are scarce or unavailable, such as during the winter and spring.

I’d never thought about that, outside of an academic consideration, since a) I don’t live lifestyle that requires such an energy rich diet, and b) I’m a vegetarian, so I’m not going to sit down to consume over 1200 kcal of meat (I feel queasy even imagining such a feast). But when I stop to think about it, yeah, my hunter-gatherer ancestors must have been well aware of this limitation, which makes the “gatherer” part of the lifestyle even more important, and must have greatly affected their preferred choices from the kill.

There is very little fat in most ungulate muscle tissues, especially the “steaks” and “roasts” of the thighs and shoulders, regardless of season, or an animal’s age, sex, or reproductive state. Mid- and northern-latitude foragers commonly fed these meat cuts to their dogs or abandoned them at the kill. The most critical fat deposits are concentrated in the brain, tongue, brisket, and rib cage; in the adipose tissue; around the intestines and internal organs; in the marrow; and in the cancellous (spongy) tissue of the bones (i.e., bone grease). With the notable exception of the brain, tongue, and very likely the cancellous tissue of bones, the other fat deposits often become mobilized and depleted when an animal is undernourished, pregnant, nursing, or in rut.

So a steak is dog food; the favored cuts are ribs and brisket and organ meats. This article, though is mainly focused on bone grease and its production by Neandertal hunters. I didn’t even know what bone grease is until the article explained it to me. Oh boy, it’s my first Neandertal recipe!

Exploitation of fat-rich marrow from the hollow cavities of skeletal elements, especially the long bones, is fairly easy and well documented in the archaeological record of Neanderthals. On the basis of ethnohistoric accounts, as well as on experimental studies, the production of bone grease, an activity commonly carried out by women, requires considerable time, effort, and fuel. Bones, especially long-bone epiphyses (joints) and vertebrae, are broken into small fragments with a stone hammer and then boiled for several hours to extract the grease, which floats to the surface and is skimmed off upon cooling. For foragers heavily dependent on animal foods, bone grease provides a calorie-dense nonprotein food source that can play a critical role in staving off rabbit starvation.

Skimming off boiled fats does not sound at all appetizing…but then I thought of pho, which is made with a stock created by boiling bones for hours, or my grandmother’s stew, which had bones boiled in the mix, which you wouldn’t eat, but made an essential contribution to the flavor. Those we don’t cool to extract the congealed fats, but they were there. Then there’s pemmican, made by pounding nuts, grains, and berries in an animal fat matrix, which now sounds like the perfect food for someone hunting for game for long hours in the cold. It’s one of those things which seems superfluous when you’re living in a world filled with easy-to-reach calories, but it makes sense. I’m going to have to think about that when I’m prepping for the Trump-induced apocalypse.

Examples of hammerstone-induced impact damage on long bones from NN2/2B.
(A) B. primigenius, Tibia dex., impacts from posteromedial (no. 4892). (B) B. primigenius, Humerus sin., impacts from posteromedial (no. 4283). (C) B. primigenius, Tibia dex., impact from anterolateral (no. 8437). (D) Equus sp., Humerus sin., impacts from posterolateral (no. 21758).

The main point of the article, though, is that they’re finding evidence of cooperative behavior in Neandertals. It analyzes a site where Neandertals had set up a bone grease processing ‘factory’ where hunters brought in their prey to be cut up, the bones broken apart, and then everything was boiled for hours along a lakeside. The place was strewn with shattered bone fragments! They also found bits of charcoal, vestiges of ancient fires. There was no evidence of anything like pottery, but they speculate that “experiments recently demonstrated that organic perishable containers, e.g., made out of deer skin or birch bark, placed directly on a fire, are capable of heating water sufficiently to process food”.

Not only do I have a recipe, I have a description of the technology used to produce the food. Anyone want to get together and make Bone Grease ala Neandertal? I’ll have to beg off on actually tasting it — vegetarian, you know — so y’all can eat it for yourselves.

It’s science!

Oh. It’s an experiment.

Man, I wish we were in the control group.

If you think the cartoon is too extreme, try reading Science magazine.

Similar conversations are taking place across the country as the federal government has paused or terminated billions of dollars of grants, proposed slashing research funding by more than 40% for key research agencies in the next fiscal year, and tried—so far without success—to cut overhead payments to universities. In response, graduate schools have reduced the size of their incoming cohorts and faculty have been anxiously watching their budgets and worrying about their own careers. “My lab is definitely going to shrink,” says Arthi Jayaraman, a chemical engineering professor at the University of Delaware.

So is U.S. academic science as a whole—perhaps dramatically. Numbers released in May by the National Science Foundation (NSF) indicate that if Congress approves the cuts to the agency proposed by the White House, the number of early-career researchers it supports could fall by 78%—from 95,700 undergraduates, graduate students, and postdocs during this fiscal year to 21,400 in 2026. Young researchers supported by other agencies would also be hit, and even senior faculty worry about their future. “It’s a nightmare,” Simon says. “I really fear for the future of science.” (NSF declined to comment for this story.)

Me, too.

Lobsters, OK — but please don’t boil the bison

You wouldn’t want to take a bath in 70°C water. That would be painful. That’s the temperature of the Grand Prismatic Spring in Yellowstone. We had a dramatic demonstration of how awful it would when a bison stumbled into the spring and was cooked to death.

That’s horrific, but unsurprising. We last visited Yellowstone several decades ago, after a major fire had swept through the place. It wasn’t exactly wholesome for the kids — black charred snags everywhere, heaps of bones where some animal had died in place, and the hot springs were surrounded with skeletons in the muck. It would have made the visit even better if the kids could have watched a massive animal die a horrible painful death. Yellowstone isn’t Disneyland.

I’d rather spare them this sort of thing, though.

Yellowstone’s thermal pools might not be capable of dissolving organic matter, but bodies tend to disappear quickly once they fall in. When Il Hun Ro, 70, fell into the Abyss Pool in the West Thumb Geyser Basin around July 7, the only evidence at the scene was several “dark clumps” and Ro’s shoe-clad foot, which was recovered from the water.

Nature isn’t kind.

I show up in two videos, but listen to them for the other guys

I was interviewed by Michael Beverly last week. It’s a two-parter, and I appear only at the end of this first video, which is mainly Dan Stern Cardinale and Jay Bundy talking about the problem of creationism. It’s good. You can bail out when they introduce me, because they were much too generous in their praise and I was cringing the whole time.

I contribute more in the second half…wait, that’s worse. Why am I recommending these videos in the first place? My appearance isn’t a good addition.

At least Michael Beverly is a good interviewer, and it’s always worthwhile to listen to Jay and Dan.