Skeptical that PMS is an adaptive response designed to break up your relationship? Me too.

In a pleasantly surprising turn of events, this week a take-down of some dubious evolutionary psychology was published by the popular media!  The original article, a perspective piece published in Evolutionary Applications, claims that moodiness associated with PMS may have historically served an adaptive role by driving infertile couples apart. 

Premenstrual syndrome (PMS) affects up to 80% of women, often leading to significant personal, social and economic costs. When apparently maladaptive states are widespread, they sometimes confer a hidden advantage, or did so in our evolutionary past. We suggest that PMS had a selective advantage because it increased the chance that infertile pair bonds would dissolve, thus improving the reproductive outcomes of women in such partnerships. We confirm predictions arising from the hypothesis: PMS has high heritability; gene variants associated with PMS can be identified; animosity exhibited during PMS is preferentially directed at current partners; and behaviours exhibited during PMS may increase the chance of finding a new partner. Under this view, the prevalence of PMS might result from genes and behaviours that are adaptive in some societies, but are potentially less appropriate in modern cultures. Understanding this evolutionary mismatch might help depathologize PMS, and suggests solutions, including the choice to use cycle-stopping contraception.

Check out the response, published by The Daily Beast, here:

Here’s the scapegoat unhappy spouses have been waiting for: According to a paper out last week by Michael R. Gillings, premenstrual syndrome (PMS) can ruin a marriage. Gillings claims that PMSing women—in infertile couples in particular—may use feelings of “animosity” as well as risk-seeking and competitive behaviors to leave their husbands and find someone new. I’m sorry to say, but the evidence in favor of this hypothesis is thinner than Always Infinity menstrual pads.

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Q: What do your friends and your fourth cousins have in common?

you smell

A: Their genetic relatedness to you.

A new study out in PNAS this week suggests that you may have even more in common with your friends than you think.  In particular, you are more likely to share your sense of smell.

“People often talk about how their friends feel like family. Well, there’s some new research out that suggests there’s more to that than just a feeling. People appear to be more like their friends genetically than they are to strangers, the research found.  Some of the genes that friends were most likely to have in common involve smell. “We tend to smell things the same way that our friends do,” Fowler says. The study involved nearly 2,000 adults.”

Read (or listen) to the story at NPR (or check out the original article here for more data and less speculation).

Why study whether we evolved this way?

baby i was born this way

John Corvino, the chair of the Philosophy Department at Wayne State University, has recently published a book, What’s Wrong With Homosexuality, which systematically knocks down objections to the equality of LGBTQ folks. He’s been discussing major points from the book in a series of clever and widely-circulated videos, and I just recently discovered that, in an episode about the biological basis of sexual orientation, he talks about that review article proposing a possible epigenetic basis for sexual orientation that I discussed here a few months ago.

Full disclosure: I found Corvino’s post, actually, because he linked to my piece about the epigenetics paper, and he did so while paying it what I consider the highest compliment it’s possible to pay a science blogger: “A nice explanation of the paper can be found here.” Which: look at me blushing.

But Corvino comes at the question from a somewhat different angle than a biologist: he says it really doesn’t matter whether there’s an inborn basis to sexual orientation.

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Friday Coffee Break, Easter/April Fools edition

black coffee with chocolate easter eggs

Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.

To get this weeks coffee break started, Amy brings us a post about the Paleo diet.  A new book by Marlene Zuk aims to show that the Paleo diet is a misinterpretation of evolution.

Jeremy takes the time this week to wonder about the effect on sea level if all the ships in the ocean were removed.  Alternatively, XKCD also wondered what would happen if you removed all the sponges.

Sarah stumbled upon this gem of a PDF book which will hopefully prove useful as she transitions from student to post doc.  She also brings up the potentially scary idea that you may not own your own DNA.  At least if the current patent situation remains upheld.  What happens if a company can own a 15-base pair fragment of DNA?

CJ continues the discussion on DNA with an article on the recent sequencing of the HeLa genome and the continued controversy regarding the ownership and publication of an individuals genome.  We continue to venture on into a strange new world with these issues.

Friday Coffee Break, Spring Break Style

Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.

beachcoffee

To get things started, CJ found a depressing study (depending on your perspective anyway) about how your attitude can affect your health.  It’s not what you would expect a study to find, but there are additional conflicting studies so take it as you will.  However, she follows it up with another article about how the privatization of space flight has a long way to go before we can all reach for the stars.

From Amy, a new variant in the African-American Y-chromosome leads to the speculation on how long ago the common ancestor of modern humans existed and/or whether there was potential interbreeding between Neanderthals and modern humans.

To follow that up, Jeremy found an interesting video that shows a morphing of the faces of human ancestry.

From Sarah, a rather fun blog post on Scientific American on how one individual looked for answers to questions and found lots of information, but failed to answer the original question.

Finally, to return to the spring break theme, the CDC reports in its weekly grand rounds about multi-drug resistant gonorrhea.

Friday Coffee Break, barnacle sex, crab lice, and chimps

credit ilovecoffeebook.com

credit ilovecoffeebook.com

Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.

Amy was learning about Synesthesia this week over at the Neurocritic Blog. Do you taste shapes or hear in colors?

Noah (@NM_Reid) must be getting tired of winter and read up on Brazilian bikini waxes making crab lice an endangered species. Tom Houslay (@tomhouslay) asks via Twitter if we need protected areas or migration corridors setup. The Bug Girl (@bug_girl) has a different point of view that you should check out.

CJ says, who doesn’t love barnacle sex? Check out the lasted news that shocked scientists, well not CJ, over at Science NOW.

Do you have a diet of milk, meat, blood? Jeremy (@JBYoder) suggests you take a look at the Empirical Zeal blog to learn how the Maasai of Kenya can consume over 200% of the daily cholesterol intake yet remain relatively healthy.

How did they get here? A new study in PNAS shows ‘gene flow’ from India to Australia 4000 years ago. See the digested report here.

Sarah (@sarahmhird) is about fairness and chimps this week. Chimps may have a sense of fairness similar to humans. If you’re curious for yourself, on the BBC lab site, you can find out how your sense of “fair” relates to others with a morality test. The Lab UK site also has other tests and your results are used for scientific research.

Late breaking addition from CJ: Being Married Helps [MALE] Professors Get seo companies Ahead.

Is epigenetics totally gay?

… epigenetics is why I love you? (Photos from the ONE National Gay & Lesbian Archive.)

In the light of much of what we know about evolution, human homosexuality doesn’t make a lot of sense. Available data suggests that sexual orientation has some inborn, probably genetic, basis. But it’s hard to reconcile that with the fact that gay men and lesbians aren’t, by definition, particularly interested in doing what it takes to pass on any genes that might have contributed to creating their orientation. Natural selection is, all things being equal, pretty good at eliminating genes that make people less likely to make babies.

I’m gay. I’m also an evolutionary biologist. You could say this particular puzzle is tailor-made to attract my interest.

It turns out that there are a number of ways that human populations might accommodate gene variants for same-sex attraction without suspending the rules of natural selection. But it’s also possible that human sexual orientation has a biological basis without being genetic. Natural selection can’t do anything about a trait if variation in that trait isn’t linked to variation at the genetic level. So I was immediately interested by the recent announcement that a team of biologists at NIMBioS, the National Institute for Mathematical and Biological Synthesis, had found that human homosexuality is due not to genetics, but to epigenetics.

However, as soon as I secured a copy of the study itself (available in PDF format here), I was disappointed to find out that the reports of a solution to this particular evolutionary enigma are somewhat exaggerated. The paper doesn’t present any new data that directly links a specific developmental process to human sexual orientation — it’s a review article, gathering existing results in support of a hypothesis that isn’t, at its most basic level, entirely new. But it’s not the job of a review article to present new data; reviews are supposed to gather up what is already known on a topic and identify what new research could do to better answer the questions that remain. And that’s exactly what the new study does.

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