Monday is going to be tricky

Our student body is fairly liberal and open-minded, but I still have to address a somewhat fraught topic in genetics tomorrow. We’ll be talking about sex determination, and this is a subject in which the science is clear, but also contrary to the conventional wisdom among non-scientists. I’ll be starting with the early 20th century idea that sex was entirely chromosomal and binary and work them up to the modern understanding that it’s bimodal, but non-binary, and a heck of a lot more complex than a single chromosome throwing a switch. I’m either going to get some pushback from more conservative students (which I will welcome!), or everyone is going to just shrug and tell me they already knew that, boomer.

Also, may I say that I really detest this explanation that I see all over the internet?

That’s also wrong. Sex varies on more than a single dimension, and we ought not to lump everyone with a variation from the stereotypical category as “intersex”. A lot of the older sources and some of the newer ones seem to be fond of calling everything that doesn’t fit their narrow binary “abnormal” or “deviant”.

Now I have to explain all that in a one hour lecture on the genetics of sex. Wheee.

OK, back to fussing over this lecture. That’s my day, that and putting together a summary of this week’s lab.

My Valentine’s Day lecture was nothing about romance

I’m still plugging away at my genetics course, and will be until May — so get used to me plopping in these long academic tutorials 3 times a week. You can ignore them, my students can’t.

I’m trusting that the students now have solid foundation in basic Mendelian genetics, so now it’s time to start cutting the mooring ropes so we can drift off into more complex and difficult waters.

Chromosomes!

I can see my future now, for at least the next four months. I have committed myself to record all of my lectures so the students have asynchronous access to the course content to maximize flexibility in case pandemic catastrophe strikes, so what I’ve got to do is:

  • Every Monday and Wednesday, record my in-class lecture, then edit it and splice in the Keynote images I use. That means I put in my regular workday, and then when I get home that evening I get to play with Final Cut Pro. Two of those a week means I won’t be doing anything fancy, just dubbing the slides and uploading it.
  • Every weekend, I put together a video to describe the lab experiment for the week. The last one might be the longest of the bunch at about a half hour, once the students get into the routine it may not be too bad.
  • Every week I also assemble a clutch of problems for the students to solve. Those go on Canvas, our course management system.

There are always glitches. Last week, the audio recording of the lecture was unlistenable, so I had to re-record the whole thing. That was better (but far from perfect) today. Today, though, the in-class technology threw up a whole bunch of problems — nothing worked until I called in IT to fix it, so I lost over 10 minutes to annoying problems. I intensely dislike the way the university has configured the AV in our classrooms.

So anyway, here’s today’s lecture. It’s about chromosomes.

Trapped by racial genetics…get out now!

I learned two things from this peculiar article, DNA Testing Forced Me To Rethink My Entire Racial Identity: that there is a terrible undercurrent of self-loathing among some black people, and that there is a pervasive over-emphasis on genes vs. culture. The latter I already knew, the former I guess I should have known.

The story is that the author, whose last name is Garcia, always assumed she was Hispanic, even though her family had no hint of Hispanic culture and didn’t even speak Spanish. Then, they took genetics tests. Shock, horror, they were just…black Americans.

The Garcias are led by a pair of oddball patriarchs who could give Clark Griswold a run for his money: my father, Joe, 71, and his brother, Tony, 68. My dad and uncle identify culturally as African-American — they were raised by a black woman from rural Maryland. But according to the family history, their father was of Mexican-Indian descent, hence the last name.

Note that important point: they identify culturally as African-American. Why would you think a genetic test would trump your lived experience?

Well, last summer, Uncle Tony sent in his DNA sample for my niece’s school project, and what ensued was a chain of existential group texts and conversations involving all the Garcias, former Garcias, and anyone married to a Garcia.

My uncle’s ethnic breakdown identified him as more than 70 percent African and 20 percent European.

“No Spanish! Not one drop!” texted my cousin Tony, an attorney in Baltimore and Uncle Tony’s son, referring to the fact that we apparently had no Mexican roots. As if we’d all missed that part.

What do they think it means to be Mexican? There is no such thing as genetically Mexican: the people of Mexico are incredibly diverse, with no one unique genetic signature. If that 20 percent European didn’t include any Spanish loci, and there were no Native American indications, then yes, it is unlikely (but not impossible) that they have Mexican ancestry. But so what? They are who they are, with their own distinct family history.

They did their own research, non-genetic research. They talked to their family, and found out about the author’s paternal grandfather.

“I once overheard my mom and dad say Uncle Joe was a wanted man,” said another new cousin, Marie Shakoor, 71. “He was wanted under the name Will Worthey, and that’s why we think he changed his name to Joe Garcia.”

My cousin Tony said our grandfather exhibited classic escapist behavior, which supported Shakoor’s theory.

“If you’re trying to change your name and your identity, you’re typically trying to evade law enforcement,” Tony said. “Choosing to be Mexican-Indian may not have been our grandfather’s first choice, but it may have been the better option.”

Now that’s interesting and genuine, maybe a little unsavory, but it’s real. The genetic test was irrelevant. Again, who you are isn’t just an assortment of alleles, it’s the cultural influences that shape you far more. Tracing your genetic lineage is just one component of your identity, and probably not the most important part.

Then the story gets a little disturbing, when we find out why the author thought it was so important.

At first, I was in disbelief. What about all those people who came up to me on the streets of New York City and started speaking Spanish? They never doubted for a moment that I was Hispanic. And I had always killed it in Spanish class, seemingly because I had Latino blood coursing through my veins. Accepting that I wasn’t a Garcia felt dangerously close to abandoning my identity.

Oh god, so many misconceptions…language isn’t transmitted via “Latino blood”. New York is a polyglot city, and culturally Hispanic people might speak their language to you because that’s how they’re comfortable talking. When I visited Iceland, strangers tended to address me in Icelandic — it wasn’t because they had a psychic understanding that I, too, was a native. Genetically, I’m also about 4% Neandertal, but I am culturally 0% Neandertal — I can’t knap a flint worth a darn and don’t have any of the words of their language flowing in my veins.

But to cringe even more…

The more I learned, the less I wanted to know. I had always liked being a Garcia. Growing up in a black community, where surnames like Smith, Brown and Jackson are ubiquitous, being a Garcia set me apart.

Perhaps more significantly, being a Garcia meant I could trace my roots to an ancestral homeland — albeit Mexico, not Africa. This was noteworthy when you consider that many African-Americans lost all ancestral ties as a result of slavery and the slave trade.

Slavers committed a great crime, breaking the chain of cultural transmission for millions of people, and denying human beings knowledge of families and tradition and customs. But why would you want to set yourself apart from your neighbors and friends who had similar family histories?

Maybe one great result of these genetic tests is that the author will stop trying to set herself apart from her community. An additional benefit would be if she’d also see the limitations of genetics, and take pride in who she actually is.

The history of genetics is too often a horror story

I had already known that the number of human chromosomes had been incorrectly reported as 48 (it’s actually 46), and that observers maintained that number for decades, seeing what they expected to see. I’ve used it as an example for years to tell students to clear their heads of preconceptions when making observations, trust what you see, and report your measurements as accurately as you can, because this tendency favoring confirmation bias can corrupt science surprisingly easily. It sounds like a relatively benign example: oops, early investigator makes a mistake counting chromosomes (I’ve done some chromosome work, it’s easy to do), and the initial observation gets perpetuated through the literature until superior techniques make the correct value obvious. Ha ha, don’t do that.

Now Dan Graur digs into the details of the mistake, and it turns out to be a goddamn horror story. There are more lessons here than I thought.

The guy who made the mistake was named Theophilus Painter, and he seems to have stumbled upwards throughout his career by being a terrible person.

The first horror: the specimens he used to make those initial chromosome counts were human testicles lopped off prisoners in an asylum. They were castrated for the crime of excessive masturbation. The methods discuss some grisly details I really didn’t need to know.

“The material upon which this study is based was obtained from three inmates of the Texas State Insane Asylum through the interest and cooperation of Dr. T. E. Cook, a physician at that institution. Two of these individuals were negroes and one was a young white man. In all three cases, the cause for the removal of the testes was excessive self abuse… The operation for the removal of the testes was made, in all three cases, under local anesthesia. An hour or two prior to the operation, the patients were given hypodermic injections of morphine in order to quiet them. This was followed by local injections of Novocain in the operating room. None of the patients exhibited any interest or excitement during the operation, nor did they show any signs of pain except when the vas deferens and the accompanying nerves were cut. One of the negroes went to sleep during the operation.”

Yikes. I guess mutilation of your patients was a routine practice in 1923. No big deal, Negroes don’t feel pain.

The second horror: as you might guess from the passage above, the whole affair was soaking in racism. Painter got the same erroneous chromosome count from all 3 of his victims, but always reported the count separately for his black and white subjects. There may also have been confirmation bias in Painter’s work, because more recent examination of his slides, which still exist, reveal that his methods were a cytological mess and it’s difficult to count chromosome numbers from them at all.

The third horror: Painter later got appointed to the presidency of the University of Texas because he was a reliably negligent creature who would happily turn a blind eye to blatantly discriminatory admission policies, and would allow segregation to continue.

Read Graur for all the details. I’m just dismayed that a point I’ve always used casually as an example of a simple error with long-term consequences is now going to have to be presented as a deeper point about bad science being used for evil. Oh, well, students should know how genetics can be misused for wicked purposes, and here’s yet another case.