Sperm-Swapping Marmosets and the Jewish People

According to the New York Times, primatologists have discovered that male marmosets occasionally blow their brother's nut.

The sperm [comes] from one male, but it [has] the DNA of the male’s brother.

Corrina Ross, who headed the University of Nebraska team that conducted the research, is quoted as saying:

“This changes how we think of marmosets as individuals, but it also changes how we think of the term at all,” she said. A male mates with a female, who gives birth to his brother’s offspring. “But most of his body also has his brother’s genes. So what is he as an individual?”

Science journalists, here’s a good rule of thumb: when a scientist tells you that her research into sperm-swapping monkey twins is really about the very nature of the self, she’s full of shit. It’s about sperm-swapping monkeys twins. The Descartes routine is for the grant review committees and the New York Times journalists who can get their attention. So please, can we have a moratorium on genetics or cognitive science articles that conclude with soulful rumination on what it means to be human?

This isn’t about “I think therefore, I am”…it’s about “bros before hos.” In all nature’s vast demesne, there’s no surely no sweeter expression of fraternal love.

A paternity test would show that the baby’s genetic father was actually its uncle. It’s possible that a female marmoset can give birth to nephews and nieces.

I guess non-Jews might be impressed by that, but if you’ve seen the family tree from my Zeyde’s Polish shtetl, you know you can pull off those very same familial relationships just by making time with first cousin Bunya for a millenium.

The article’s got me thinking about “kin selection,” evolutionary biology’s explanation for why we sacrifice our own best interests for the wellbeing of family. The love a mother feels for her child, for example, is said to be a nifty trick designed by natural selection to help Mom spread the genes she shares with her child. Kin selection has been used to help explain everything from the social organization of supremely self-sacrificing “eusocial” creatures such as termites and naked mole rats, to the high rates at which stepchildren are abused (the so-called Cinderella Effect).

Willingness to sacrifice is alleged to be more-or-less proportional to the amount of DNA we share. When asked if he would lay down his life for his brother, biologist J.B.S. Haldane said, famously joked “No, but for two brothers or eight cousins.” Funny ‘cuz it’s true?

And how about this one: "I'd lay down my life for two brothers, eight cousins…or fifty-four random Ashkenazi Jews." Is a traditionally endogamous group like Ashkenazi Jews more prone than most other populations to in-group altruism? We're a people obsessed with our "peoplehood." Is "peoplehood" easier when you've got your base pairs in the same order? I know someone who would say so…