Monday, September 02, 2019

Batch of links

- Here’s a really neat website called Reading Length: you start by taking a quick test to determine how many words a minute you read on average, and then you enter the title of any book (in English) and you’ll know how long it should take you to read it. This is how I figured out that I had plenty of time to reread The Complete MAUS by Art Spiegelman (just under 5 hours) before leaving for the summer!

- The New York Times published an article last week about the latest research into the effect of genes on sexual orientation, which suggests that genes are responsible for only about a third of the reasons why someone might be homosexual. Other reasons include social and environmental factors. (This is not to be misconstrued as saying that people who are homosexual have in any way chosen their sexual orientation – I’ve yet to hear of a single case where that would be true, and I for one certainly didn’t choose to be straight. It simply means that raw data from one’s DNA doesn’t account for everything. Another simplified example: one’s DNA might code for “being tall”, but if that person doesn’t get all the necessary nutrients during their growth period, thein their height will not be optimal, through no fault of their own and certainly through no conscious decision on their part.)

We already knew that DNA isn’t the only factor in determination of sexual preferences. If it were, identical twins would always have the same sexual orientation, but apparently a gay identical twin has only a 20% chance of their twin being gay as well. That being said, the most glaring omission here, in my opinion, is that this article did not at all bring up prenatal endocrine influences, which are known to play a role in sexual preferences without being directly genetic!

- I already knew that androgen levels in utero are correlated with sexual orientation, especially for female fetuses (see here or here, though some reach different conclusions with the same evidence here). In short, as far as we know, higher levels of exposure to androgen hormones for a female fetus are correlated with a higher chance of the grown woman being a lesbian.

It’s different for male fetuses. In university, I studied both biology and psychology, where I took classes in ethology, bioethics as well as sex and gender psychology, and here’s how the topic was presented. I was taught that it had to do with epigenetics, that is, that there might be one or – more likely – several genes that code for homosexuality, , but whether or not those genes are expressed depends on a specific combination of genes or on factors external to the individual’s DNA (such as the environment in which they grow up). So at that point (c. 2001), the research showed that gay men were more likely to be the youngest sibling in the family. (I don’t remember specifically hearing about whether the sex of their older siblings made a difference.) The leading theory at the time was that perhaps because they were the youngest, their mother “babied” them and they then identified with her more, and IF they had the genes that predisposed them to being gay, those genes were then activated. It was the kind of explanation that “sounded legit” and there wasn’t yet any evidence to refute it, so it stood for a while, even though a lot of men are close to their mom without being gay and vice versa. But over the summer I learned that this was debunked a few years ago: this article explains that a woman pregnant with a male fetus makes antibodies that target the Y chromosome, and the more male fetuses she carries over her life, the higher the level of those antibodies. This means that each subsequent male child is that much more likely to be gay than his older brother(s). It’s a very interesting example of the influence of the environment (in this case, the womb) on the wiring of the brain, in a way that is not technically genetic, but is still independent of any influence after birth.

Even then, there are of course other factors at play. As anecdotal evidence, my oldest paternal uncle has a male partner, but to the best of my knowledge, all four of his younger brothers are heterosexual. We obviously still have a lot to learn here.

- In more science news, there’s a vaccine to prevent being allergic to one’s cat. The catch? The vaccine is for the cat.

- Some fairy tales may be more than 6,000 years old. I really liked this article because the methodology was similar to studies of lineage through DNA, but applied to languages.

- There’s a movement called Statues for Equality that aims to increase the number of statues of women in public spaces. Did you know that less than 3% of statues in New York are women? Well, 10 new statues were unveiled last week, all women, and more are to come.

- Apparently, mothers-in-law poisoning their son’s wife is a thing. The original Dear Prudence story is gold, and I also loved this Ask Polly response to the woman with the mushroom allergy.

- And to my dismay, glass is no longer being recycled in my neighborhood. This is going on in other residential neighborhoods as well. I mean, I came back from my summer in Montreal feeling badly that we don’t have a municipal composting program, and hey, it got even worse.

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