New uses for the pubic microbiome?

A few weeks ago I posted that 80,000,000 bacteria may be transferred when you make-out with someone for greater than 10 seconds. Perhaps it’s no surprise then that a bacterial signature may also be transferred during other intimate activities.

At one point in the study, the two people who lived together suddenly had more similarity in their pubic hair bacteria than they had before. It turned out that they’d had sex 18 hours before the sample collection. Ergo, the study authors suggest, a forensic investigator could use microbial shifts to help prove that two people had had intimate contact.

Data came from a study where researchers looked at head and pubic hair samples from seven individuals, finding that pubic hair microbes are more “individualized” than head hair microbes. And while the authors acknowledge this is very, very preliminary – the (distant) applications of microbial evidence are interesting to think about:

 “The implication of this present study is that the transfer of bacteria between victim and offender, in rape cases, may provide a new way of linking the offender to the victim, in instances in which no human DNA is transferred.”

Read more about the study here.

 

The keywords of this post are ones I’m unwilling to Google Image search – so here’s an alpaca with silly hair. Relevant? No. Amusing and better than what would come up under a search for “pubic hair microbiome”? Yes.

Under selection, an endangered species runs low on evolutionary “fuel”

Atlapetes pallidiceps

A pale-headed brushfinch, Atlapetes pallidiceps. (Wikimedia Commons:Aves y Conservación/NBII Image Gallery)

The pale-headed brushfinch, Atlapetes pallidiceps, is a conservation success story, or at least the first chapter of one. The birds were thought to be extinct, until a 1998 survey [PDF] of Ecuador’s Yunguilla Valley found four nesting pairs, and observed them foraging for insects and fruit. Following that rediscovery, the Fundacion Jocotoco secured a reserve encompassing the brush finches’ known territory, and took steps to control brood-parasitic cowbirds that were threatening them. Now, the population is five times bigger, with as many as 200 of the birds living in the reserve.

Have the brush finches’ rebounded enough to secure their population for the future? Populations that decline so precipitously can lose genetic variation, and may not regain it even if their numbers increase again. With reduced genetic variation, species that have undergone such a “population bottleneck” event may be unable to respond to natural selection imposed by disease or changing environments.

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Finding bias in discussions of campus sexual assault data

When science is used to support proposed changes to public policy, it isn’t uncommon for opponents of the policy changes to question the legitimacy of the studies cited. This often leads to rejection of scientific studies for completely unscientific reasons, and can even devolve into outright scientific denialism.

Earlier this year, the Obama administration proposed controversial policy changes related to sexual assault prevention on college campuses. As evidence of the need for reform, the White House Task Force to Protect Students from Sexual Assault cited the statistic that one in five women attending college are sexually assaulted at some point during their time on campus. Unsurprisingly, those opposed to the sexual assault policy changes are questioning the legitimacy of both the statistic and the study that produced it.

Recently, Emily Yoffe published an article in which she argues that the statistics on sexual assault presented by the Obama administration are misleading. Yoffe describes herself as “bringing some healthy skepticism to the hard work of putting a number on the prevalence of campus rape.” The thing is, skepticism in and of itself isn’t really that helpful unless you understand how to think critically about scientific studies. Yoffe’s article presents a good example of how misconceptions about research methodology and statistics can derail an otherwise productive conversation and steer it towards the territory of science denialism.

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Purple martins, helped and harmed by humans

My grandfather, a farmer in rural Virginia, was never much worried about saving endangered species or stopping climate change, or any environmental issue that didn’t directly impact next year’s soybean harvest. But as long as I can remember, he maintained a tiny apartment house on a pole in his back yard — just for purple martins.

Martins are glossy, deep-purple swallows that nest in big colonies. Originally, they used cavities in dead tree trunks and cliffs, but in eastern North America they’re now entirely dependent on human-made birdhouses like my grandfather’s. In a great video, Adam Cole of NPR’s Skunk Bear, talks to some martin landlords, discusses some of the challenges the birds face in modern times, and goes on an expedition to find one of the roosts where they gather in huge flocks before migrating to South America for the winter.

Bringing back the “king” of American forests

The American chestnut used to be one of the most common trees in North American hardwood forests, providing enormous crops of nuts that supported birds and other wildlife, and a source of robust, rot-resistant lumber for human use. But American chestnuts were nearly wiped out by the introduction of a virulent chestnut blight from Asia.

But now, after years of selective breeding and some careful genetic engineering, biologists at the State University of New York and the American Chestnut Foundation have produced blight-resistant chestnuts and they’re getting ready to start restoring the population with a crowd-funding campaign. If American chestnuts couldn’t evolve to cope with blight on their own, they may be one of the first species to get an evolutionary helping hand from humans.

Don’t Buy This

One of the co-founders of the structure of the DNA, James Watson, is selling his Nobel Prize medallion.

And since he’s bringing himself back into the media spotlight, an article at slate reminds us all of some of his verbal gems.:

“Whenever you interview fat people you feel bad, because you know you’re not going to hire them.”

When speaking about women in science, “I think having all these women around makes it more fun for the men but they’re probably less effective.”

What else did the resident bad grandpa of science say recently? Read more here. 

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