Today’s lecture was all about mechanisms of sex determination. I didn’t finish, but I knew I wouldn’t — more to come on Wednesday.
Today’s lecture was all about mechanisms of sex determination. I didn’t finish, but I knew I wouldn’t — more to come on Wednesday.
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.
Linux to the rescue! I managed to get my most recent genetics recording uploaded.
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.
Very exciting, but unfortunately this week’s lab video is largely about the glamorous side of lab life: washing glassware. Also about looking up stuff in databases. But maybe in another week we’ll get those F1 results!
Yet another lecture video. I’m still having a few tech problems — the camera died on me about 45 minutes in. I know what went wrong, though, so next time will be perfect!
Here’s the next step in our genetics lab experiment, crossing brown-eyed and scarlet-eyed flies.
What will the hybrid F1s look like?
I’ve been teaching non-stop all day, and boy are my brains tired. I end this exhausting day by dumping today’s genetics lecture on the world.
I should probably go to bed soon.
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:
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.
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.
