Category Archives: Sex Science

The evolutionary puzzle of homosexuality

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In the last two decades, dozens of scientific papers have been published on the biological origins of homosexuality – another announcement was made last week. It’s becoming scientific orthodoxy. But how does it fit with Darwin’s theory of evolution?

Macklemore and Ryan Lewis’s hit song Same Love, which has become an unofficial anthem of the pro-gay marriage campaign in the US, reflects how many gay people feel about their sexuality.

It mocks those who “think it’s a decision, and you can be cured with some treatment and religion – man-made rewiring of a predisposition”. A minority of gay people disagree, maintaining that sexuality is a social construct, and they have made a conscious, proud choice to take same-sex partners.

But scientific opinion is with Macklemore. Since the early 1990s, researchers have shown that homosexuality is more common in brothers and relatives on the same maternal line, and a genetic factor is taken to be the cause. Also relevant – although in no way proof – is research identifying physical differences in the brains of adult straight and gay people, and a dizzying array of homosexual behaviour in animals.

But since gay and lesbian people have fewer children than straight people, a problem arises.001

“This is a paradox from an evolutionary perspective,” says Paul Vasey from the University of Lethbridge in Canada. “How can a trait like male homosexuality, which has a genetic component, persist over evolutionary time if the individuals that carry the genes associated with that trait are not reproducing?”

Scientists don’t know the answer to this Darwinian puzzle, but there are several theories. It’s possible that different mechanisms may be at work in different people. Most of the theories relate to research on male homosexuality. The evolution of lesbianism is relatively understudied – it may work in a similar way or be completely different.


The genes that code for homosexuality do other things too

The allele – or group of genes – that sometimes codes for homosexual orientation may at other times have a strong reproductive benefit. This would compensate for gay people’s lack of reproduction and ensure the continuation of the trait, as non-gay carriers of the gene pass it down.

There are two or more ways this might happen. One possibility is that the allele confers a psychological trait that makes straight men more attractive to women, or straight women more attractive to men. “We know that women tend to like more feminine behavioural features and facial features in their men, and that might be associated with things like good parenting skills or greater empathy,” says Qazi Rahman, co-author of Born Gay; The Psychobiology of Sex Orientation. Therefore, the theory goes, a low “dose” of these alleles enhances the carrier’s chances of reproductive success. Every now and then a family member receives a larger dose that affects his or her sexual orientation, but the allele still has an overall reproductive advantage.

Another way a “gay allele” might be able to compensate for a reproductive deficit is by having the converse effect in the opposite sex. For example, an allele which makes the bearer attracted to men has an obvious reproductive advantage to women. If it appears in a man’s genetic code it will code for same-sex attraction, but so long as this happens rarely the allele still has a net evolutionary benefit.

There is some evidence for this second theory. Andrea Camperio-Ciani, at the University of Padova in Italy, found that maternal female relatives of gay men have more children than maternal female relatives of straight men. The implication is that there is an unknown mechanism in the X chromosome of men’s genetic code which helps women in the family have more babies, but can lead to homosexuality in men. These results haven’t been replicated in some ethnic groups – but that doesn’t mean they are wrong with regards to the Italian population in Camperio-Ciani’s study.


Gay people were ‘helpers in the nest’

The fa'afafine of Samoa dislike being called "gay" or "homosexual"

The fa’afafine of Samoa dislike being called “gay” or “homosexual”

Some researchers believe that to understand the evolution of gay people, we need to look at how they fit into the wider culture.

Paul Vasey’s research in Samoa has focused on a theory called kin selection or the “helper in the nest” hypothesis. The idea is that gay people compensate for their lack of children by promoting the reproductive fitness of brothers or sisters, contributing money or performing other uncle-like activities such as babysitting or tutoring. Some of the gay person’s genetic code is shared with nieces and nephews and so, the theory goes, the genes which code for sexual orientation still get passed down.

Sceptics have pointed out that since on average people share just 25% of their genetic code with these relatives, they would need to compensate for every child they don’t have themselves with two nieces or nephews that wouldn’t otherwise have existed. Vasey hasn’t yet measured just how much having a homosexual orientation boosts siblings’ reproduction rate, but he has established that in Samoa “gay” men spend more time on uncle-like activities than “straight” men.

“No-one was more surprised than me,” says Vasey about his findings. His lab had previously shown that gay men in Japan were no more attentive or generous towards their nieces and nephews than straight, childless men and women. The same result has been found in the UK, US and Canada.

Vasey believes that his Samoan result was different because the men he studied there were different. He studied the fa’afafine, who identify as a third gender, dressing as women and having sex with men who regard themselves as “straight”. They are a transgender group who do not like to be called “gay” or “homosexual”.

Vasey speculates that part of the reason the fa’afafine are more attentive to their nephews and nieces is their acceptance in Samoan culture compared to gay men in the West and Japan (“You can’t help your kin if they’ve rejected you”). But he also believes that there is something about the fa’afafine way of life that means they are more likely to be nurturing towards nieces and nephews, and speculates that he would find similar results in other “third gender” groups around the world.

If this is true, then the helper in the nest theory may partly explain how a genetic trait for same-sex attraction hasn’t been selected away. That hypothesis has led Vasey to speculate that the gay men who identify as men and have masculine traits – that is to say, most gay men in the West – are descended from men who had a cross-gendered sexuality.


Gay people do have children

gay-parents_opt

In the US, around 37% of lesbian, gay, bisexual and transsexual people have a child, about 60% of which are biological. According to the Williams Institute, gay couples that have children have an average of two.

These figures may not be high enough to sustain genetic traits specific to this group, but the evolutionary 002biologist Jeremy Yoder points out in a blog post that for much of modern history gay people haven’t been living openly gay lives. Compelled by society to enter marriages and have children, their reproduction rates may have been higher than they are now.

How many gay people have children also depends on how you define being “gay”. Many of the “straight” men who have sex with fa’afafine in Samoa go on to get married and have children.

“The category of same-sex sexuality becomes very diffuse when you take a multicultural perspective,” says Joan Roughgarden, an evolutionary biologist at the University of Hawaii. “If you go to India, you’ll find that if someone says they are ‘gay’ or ‘homosexual’ then that immediately identifies them as Western. But that doesn’t mean there’s no homosexuality there.”

Similarly in the West, there is evidence that many people go through a phase of homosexual activity. In the 1940s, US sex researcher Alfred Kinsey found that while just 4% of white men were exclusively gay after adolescence, 10% had a three-year period of gay activity and 37% had gay sex at some point in their lives.

A national survey of sexual attitudes in the UK last year came up with lower figures. Some 16% of women said they had had a sexual experience with another woman (8% had genital contact), and 7% of men said they had had a sexual experience with a man (with 5% having genital contact).

But most scientists researching gay evolution are interested in an ongoing, internal pattern of desire rather than whether people identify as gay or straight or how often people have gay sex. “Sexual identity and sexual behaviours are not good measures of sexual orientation,” says Paul Vasey. “Sexual feelings are.”


It’s not all in the DNA

Qazi Rahman says that alleles coding for same sex attraction only explain some of the variety in human sexuality. Other, naturally varying biological factors come into play, with about one in seven gay men, he says, owing their sexuality to the “big brother effect”.

This has nothing to do with George Orwell, but describes the observation that boys with older brothers are significantly more likely to become gay – with every older brother the chance of homosexuality increases by about a third. No-one knows why this is, but one theory is that with each male pregnancy, a woman’s body forms an immune reaction to proteins that have a role in the development of the male brain. Since this only comes into play after several siblings have been born – most of whom are heterosexual and go on to have children – this pre-natal quirk hasn’t been selected away by evolution.

Exposure to unusual levels of hormone before birth can also affect sexuality. For example, female foetuses exposed to higher levels of testosterone before birth show higher rates of lesbianism later on. Studies show that “butch” lesbian women and men have a smaller difference in length between their index and ring fingers – a marker of pre-natal exposure to testosterone. In “femme” lesbians the difference has been found to be less marked.

Brothers of a different kind – identical twins – also pose a tricky question. Research has found that if an identical twin is gay, there is about a 20% chance that the sibling will have the same sexual orientation. While that’s a greater likelihood than random, it’s lower than you might expect for two people with the same genetic code.

William Rice, from the University of California Santa Barbara, says that it may be possible to explain this 003by looking not at our genetic code but at the way it is processed. Rice and his colleagues refer to the emerging field of epigenetics, which studies the “epimarks” that decide which parts of our DNA get switched on or off. Epimarks get passed on to children, but only sometimes. Rice believes that female foetuses employ an epimark that makes them less sensitive to testosterone. Usually it’s not inherited, but occasionally it is, leading to same-sex preference in boys.

Dr William Byne, editor-in-chief of the journal LGBT Health, believes sexuality may well be inborn, but thinks it could be more complicated than some scientists believe. He notes that the heritability of homosexuality is similar to that for divorce, but “social science researchers have not… searched for ‘divorce genes’. Instead they have focused on heritable personality and temperamental traits that might influence the likelihood of divorce.”

For Qazi Rahman, it’s the media that oversimplifies genetic theories of sexuality, with their reports of the discovery of “the gay gene”. He believes that sexuality involves tens or perhaps hundreds of alleles that will probably take decades to uncover. And even if heterosexual sex is more advantageous in evolutionary terms than gay sex, it’s not only gay people whose sexuality is determined by their genes, he says, but straight people too.

Complete Article HERE!

What Makes These Dominican Children Grow Penises at Puberty?

By Michele Debczak

guevedoces

In the Dominican Republic, the phenomenon of children who were raised female appearing to swap sexes at puberty is so common it even has a name. Guevedoces roughly translates to “penis [or “balls”] at 12,” and it’s the result of a rare enzyme deficiency that delays crucial steps of male sexual development until puberty.

When guevedoces are born, they appear to have external female genitalia even though their genes and internal reproductive organs are male. Parents assume their children are girls and raise them as such. But when these children begin producing large amounts of testosterone at puberty, their testes descend and they grow a penis—in addition to all the other changes that come along with male adolescence. 

Sexual development normally begins in the womb, and the same is true for guevedoces. Whether the fetus has one X chromosome or two, for the first several weeks of development its genes follow the same blueprint for both sexes. Then, sometime around the eight-week mark, the sex chromosomes get to work. For males, the undeveloped gonads become testicles and they start to release male hormones, including testosterone. In a structure called the tubercle, an enzyme called 5-alpha-reductase converts the testosterone to a stronger hormone called dihydrotestosterone (DHT), which is necessary to develop external genitalia. It’s this hormone that turns the tubercle into a penis; without it, it develops into a clitoris.

The rare enzyme deficiency found in guevedoces leaves them unable to develop external male genitalia in the womb. They still produce plenty of testosterone, which triggers the development of internal structures like the epididymis and vas deferens, but the lack of DHT makes the babies appear female at birth. It’s not until the second surge of testosterone these children receive at puberty that they grow testes and a penis.

The condition is thought to be genetic, tracing back to the female founder of a small village in the Dominican Republic’s mountainous hinterland. Outside of the nation, it’s incredibly rare.

For some guevedoces, being raised as female wasn’t an easy experience. “I never liked to dress as a girl, and when they bought me toys for girls, I never bothered playing with them,” Johnny, who had grown up as Felicita, told BBC Two, which features these kids in the second episode of the series Countdown to Life: The Extraordinary Making of You. “When I saw a group of boys, I would stop to play ball with them.” When Johnny, now 24, began to undergo physical changes, he was taunted at school and called nasty names by his classmates. He’s had a number of short-term girlfriends since going through puberty and dreams of one day getting married and starting a family. Another child named Carla began the process of transitioning to Carlos at age 9; he can be seen receiving a smile-inducing haircut in the photo above.

Most people with this condition live out their adult lives as men, but some choose to undergo surgery and remain female. The discovery of this disorder in the 1970s led to the development of a best-selling drug called finasteride, which is commonly prescribed to treat benign enlargement of the prostate and male pattern baldness. (You may know it by the brand name Propecia.) The drug mimics the enzyme deficiency by blocking the action of 5-alpha-reductase.

You can learn more about this rare condition and the people who have it on the BBC Two series Countdown to Life: The Extraordinary Making of You.

Complete Article HERE!

Does Manspreading Work?

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Participants in a “No Trousers Day” flashmob ride the London Underground in 2012.

A study suggests people find expansive, space-consuming postures more romantically attractive

Manspreading might make you the villain of the morning L train, but a new study suggests it could also make you lucky in love. People who adopted “expansive postures”—widespread limbs and a stretched-out torso—in speed-dating situations garnered more romantic interest than those who folded their arms in “closed postures,” the researchers found.

For her recent paper, published this week in Proceedings of the National Academy of Sciences, Tanya Vacharkulksemsuk, a post-doctoral research fellow at the University of California, Berkeley, performed two studies. First, she and her team watched videos of 144 speed-dates and correlated them with the participants’ ratings of each other. People who sat in expanded postures were deemed more attractive, and for both men and women, postural expansiveness nearly doubled their chances of getting a “yes” response to a second date. Even laughing and smiling didn’t work as well as spreading out, Vacharkulksemsuk found.

Examples of expansive postures used in the study

Examples of expansive postures used in the study

Next, Vacharkulksemsuk posted pictures of people in open and closed postures on a dating site. Again, those in the expansive postures were about 25 percent more likely to generate interest from another user. However, this strategy worked much better for men than women. Men, overall, received far fewer bites than women did, but 87 percent of their “yesses” came in response to an open posture. For women, meanwhile, 53 percent of “yes” responses came when they were in an expansive posture.

Examples of contractive postures used in the study

Examples of contractive postures used in the study

In a separate test, Vacharkulksemsuk found that both the male and female “expansive” photos were considered more dominant than the “closed” photos. That dominance might suggest an abundance of resources and a willing to share those resources. When potential romantic partners are evaluating each other for just a few seconds, in other words, money talks—mainly through bodily breadth.

So should you rush to change your Tinder picture to something a little less pouty and a little more Backstreet Boys cira Millennium? Like with almost every study, there are reasons to be skeptical. “Power poses” made a big splash in 2010 when it was found that adopting them could tweak hormone levels—then sparked controversy after a follow-up study failed to replicate the effect.

Several researchers who weren’t involved with the study expressed doubts about its methodology. Agustín Fuentes, a professor of anthropology at the University of Notre Dame, said the findings might be a sign of general social preference for openness, but not necessarily that open-looking poses are sexier. “The connection to mating/dating assessment they suggest is superficial,” he said in an email.

Irving Biederman, a professor of neuroscience at the University of Southern California, said some of the “expansive” women might have looked vulnerable, rather than powerful.

To Vacharkulksemsuk, though, the fact that her study subjects rated both the male and female “expansive” photos as dominant—and found that dominance attractive—might signal the start of something very exciting. For decades, women have been told they’re most attractive when they’re demure, high-pitched, and generally non-threatening. This data “may be signifying a change in what men are looking for in women,” she said. Perhaps commuters should brace themselves for the rise of fem-spreading.

Complete Article HERE!

What Happens To Men Who Stay Abstinent Until Marriage?

by Sarah Diefendorf

Russell Wilson and his girlfriend Ciara

Seattle Seahawks quarterback Russell Wilson and his girlfriend Ciara arrive at a White House State Dinner in April.

Seattle Seahawks quarterback Russell Wilson and his girlfriend, the singer Ciara, recently announced plans to remain sexually abstinent until marriage.

It was a vow that came as a surprise to many. After all, sexual purity is a commitment that is historically expected of, associated with – even demanded of – women. However, sexual abstinence is not something assumed of men, especially men like Russell Wilson.

Wilson, an accomplished, attractive athlete, embodies contemporary ideals of masculinity, which include style, wealth and, yes, sexual prowess.

So how does a man like Russell Wilson navigate a commitment to abstinence while upholding ideals of masculinity? Wilson’s status as an athlete and heartthrob is likely giving him what sociologist CJ Pascoe calls “jock insurance.” In other words, due to his celebrity status, he can make traditionally nonmasculine choices without having his masculinity questioned.

But what does it mean for a man who isn’t in the limelight, who makes a similar type of commitment to abstinence? And what does it mean for the women they date, and might eventually marry?

I’ve been researching men who pledge sexual abstinence since 2008, work that comes out of a larger scholarly interest in masculinities, religion and sex education.

While men make this commitment with the good intentions for a fulfilling marriage and sex life, my research indicates that the beliefs about sexuality and gender that come hand in hand with these pledges of abstinence do not necessarily make for an easy transition to a married sexual life.

Who’s Pledging “Purity?”

Comedian Joy Behar recently joked that abstinence is what you do after you’ve been married for a long time. Here, Behar makes two assumptions. One is that sexual activity declines both with age and the time spent in a relationship. This is true.

The second is that abstinence is not something you do before marriage. For the most part, this is true as well: by age 21, 85% of men and 81% of women in the United States have engaged in sexual intercourse.

purity ringIf we compare these numbers to the average age of first marriage in the United States – 27 for women, and 29 for men – we get the picture: most people are having sex before marriage.

Still, some in the United States are making “virginity pledges,” and commit to abstinence until marriage. Most of the data that exist on this practice show that those who make the pledges will do so in high school, often by either signing a pledge card or donning a purity ring.

Research on this population tells us a few things: that those who pledge are more likely to be young women, and that – regardless of gender – an abstinence pledge delays the onset of sexual activity by only 18 months. Furthermore, taking a virginity pledge will often encourage other types of sexual behavior.

Virgins In Guyland

But little is known about men who pledge and navigate this commitment to abstinence.

I was curious about how men maintain pledges in light of these statistics, and also balance them with expectations about masculinity. So in 2008, I began researching a support group of 15 men at an Evangelical church in the Southwest. All members were white, in their early to mid-20’s, single or casually dating – and supporting each other in their decisions to remain abstinent until marriage.

The group, called The River, met once a week, where, sitting on couches, eating pizza or talking about video games, they’d eventually gravitate toward the topic that brought them all together in the first place: sex.

On the surface, it would seem impossible for these men to participate in what sociologist Michael Kimmel calls “Guyland” – a developmental and social stage driven by a “guy code” that demands, among other things, sexual conquest and detached intimacy.

Rather, the men of The River approach sex as something sacred, a gift from God meant to be enjoyed in the confines of the marriage bed. At the same time, these men struggle with what they describe as the “beastly elements” – or temptations – of sexuality. And it is precisely because of these so-called beastly elements that these men find each other in the same space every week.

The men of The River grappled with pornography use, masturbation, lust and same-sex desire, all of which can potentially derail these men from their pledge.

It raises an interesting dilemma: to these men, sex is both sacred and beastly. Yet the way they navigate this seeming contradiction actually allows them to exert their masculinity in line with the demands of Guyland.

Group members had an elaborate network of accountability partners to help them resist temptations. For example, one had an accountability partner who viewed his weekly online browsing history to make sure he wasn’t looking at pornography. Another accountability partner texted him each night to make sure that he and his girlfriend were “behaving.”

While these behaviors may seem unusual, they work in ways that allow men to actually assert their masculinity. Through what sociologist Amy Wilkins calls “collective performances of temptation,” these men are able to discuss just how difficult it is to refrain from the beastly urges; in this way, they reinforce the norm that they are highly sexual men, even in the absence of sexual activity.

The River, as a support group, works largely in the same way. These men are able to confirm their sexual desires in a homosocial space – similar to Kimmel’s research in Guyland – from which Kimmel notes that the “actual experience of sex pales in comparison to the experience of talking about sex.”

A ‘Sacred Gift’ – With Mixed Returns

The men of The River believed that the time and work required to maintain these pledges would pay off in the form of a happy and healthy marriage.

Ciara, in discussing her commitment to abstinence with Russell Wilson, similarly added that she believes such a promise is important for creating a foundation of love and friendship. She stated that, “if we have that [base] that strong, we can conquer anything with our love.”

So what happened once after the men of The River got married? In 2011, I followed up with them.

All but one had gotten married. But while the transition to married life brought promises of enjoying their “sacred gift from God,” this gift was fraught.

Respondents reported that they still struggled with the beastly elements of sexuality. They also had the added concern of extramarital affairs. Furthermore – and perhaps most importantly – men no longer had the support to work through these temptations.

There were two reasons behind this development.

First, respondents had been told, since they were young, that women were nonsexual. At the same time, these men had also been taught that their wives would be available for their pleasure.

It’s a double standard that’s in line with longstanding cultural ideals of the relationship between femininity and purity. But it’s a contradiction that leaves men unwilling to open up to the very women they’re having sex with.

These married men and women were not talking to each other about sex. Rather than freely discussing sex or temptation with their wives (as they had done with their accountability partners), the men simply tried to suppress temptation by imagining the devastation any sexual deviations might cause their wives.

after marriage

After marriage, the men felt left to their own devices.

Second, these men could no longer reach out to their support networks due to their own ideals of masculinity. They had been promised a sacred gift: a sexually active, happy marriage. Yet many weren’t fully satisfied, as evidenced by the continued tension between the sacred and beastly. However, to open up about these continued struggles would be to admit failure as masculine, Christian man.

In the end, the research indicates that a pledge of sexual abstinence works to uphold an ideal of masculinity that disadvantages both men and women.

After 25 years of being told that sex is something dangerous that needs to be controlled, the transition to married (and sexual) life is difficult, at best, while leaving men without the support they need. Women, meanwhile, are often left out of the conversation entirely.

So when we urge abstinence in place of healthy conversations about sex and sexuality, we may be undermining the relationships that are the driving goal of these commitments in the first place.

Complete Article HERE!

No, Scientists Have Not Found the ‘Gay Gene’

By Ed Yong

The media is hyping a study that doesn’t do what it says it does.

A woman works with human genetic material at a laboratory in Munich May 23, 2011. On May 25, 2011 the ethic commission of the German lower house of parliament (Bundestag) will discuss about alternative proposals for a new law on the use of preimplantation genetic diagnosis (PGD). Preimplantation genetic diagnosis (Praeimplantationsdiagnostik) is a technique used to identify genetic defects in embryos created through in vitro fertilization (IVF) before pregnancy, which is banned by German legislation.

This week, a team from the University of California, Los Angeles claimed to have found several epigenetic marks—chemical modifications of DNA that don’t change the underlying sequence—that are associated with homosexuality in men. Postdoc Tuck Ngun presented the results yesterday at the American Society of Human Genetics 2015 conference. Nature News were among the first to break the story based on a press release issued by the conference organisersOthers quickly followed suit. “Have They Found The Gay Gene?” said the front page of Metro, a London paper, on Friday morning.

Meanwhile, the mood at the conference has been decidedly less complimentary, with several geneticists criticizing the methods presented in the talk, the validity of the results, and the coverage in the press.

Ngun’s study was based on 37 pairs of identical male twins who were discordant—that is, one twin in each pair was gay, while the other was straight—and 10 pairs who were both gay. He analysed 140,000 regions in the genomes of the twins and looked for methylation marks—chemical Post-It notes that dictate when and where genes are activated. He whittled these down to around 6,000 regions of interest, and then built a computer model that would use data from these regions to classify people based on their sexual orientation.

The best model used just five of the methylation marks, and correctly classified the twins 67 percent of the time. “To our knowledge, this is the first example of a biomarker-based predictive model for sexual orientation,” Ngun wrote in his abstract.

The problems begin with the size of the study, which is tiny. The field of epigenetics is littered with the corpses of statistically underpowered studies like these, which simply lack the numbers to produce reliable, reproducible results.

Unfortunately, the problems don’t end there. The team split their group into two: a “training set” whose data they used to build their algorithm, and a “testing set”, whose data they used to verify it. That’s standard and good practice—exactly what they should have done. But splitting the sample means that the study goes from underpowered to really underpowered.

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There’s also another, larger issue. As far as could be judged from the unpublished results presented in the talk, the team used their training set to build several models for classifying their twins, and eventually chose the one with the greatest accuracy when applied to the testing set. That’s a problem because in research like this, there has to be a strict firewall between the training and testing sets; the team broke that firewall by essentially using the testing set to optimise their algorithms.

If you use this strategy, chances are you will find a positive result through random chance alone. Chances are some combination of methylation marks out of the original 6,000 will be significantly linked to sexual orientation, whether they genuinely affect sexual orientation or not. This is a well-known statistical problem that can be at least partly countered by running what’s called a correction for multiple testing. The team didn’t do that. (In an email to The Atlantic, Ngun denies that such a correction was necessary.)And, “like everyone else in the history of epigenetics studies they could not resist trying to interpret the findings mechanistically,” wrote John Greally from the Albert Einstein College of Medicine in a blog post. By which he means: they gave the results an imprimatur of plausibility by noting the roles of the genes affected by the five epi-marks. One is involved in controlling immune genes that have been linked to sexual attraction. Another is involved in moving molecules along neurons. Could epi-marks on these genes influence someone’s sexual attraction? Maybe. It’s also plausible that someone’s sexual orientation influences epi-marks on these genes. Correlation, after all, does not imply causation.

So, ultimately, what we have is an underpowered fishing expedition that used inappropriate statistics and that snagged results which may be false positives. Epigenetics marks may well be involved in sexual orientation. But this study, despite its claims, does not prove that and, as designed, could not have.

In a response to Greally’s post, Ngun admitted that the study was underpowered. “The reality is that we had basically no funding,” he said. “The sample size was not what we wanted. But do I hold out for some impossible ideal or do I work with what I have? I chose the latter.” He also told Nature News that he plans to “replicate the study in a different group of twins and also determine whether the same marks are more common in gay men than in straight men in a large and diverse population.”Great. Replication and verification are the cornerstones of science. But to replicate and verify, you need a sturdy preliminary finding upon which to build and expand—and that’s not the case here. It may seem like the noble choice to work with what you’ve got. But when what you’ve got are the makings of a fatally weak study, of the kind well known to cause problems in a field, it really is an option—perhaps the best option—to not do it at all. (The same could be said for journalists outside the conference choosing to cover the study based on a press release.)As Greally wrote in his post: “It’s not personal about [Ngun] or his colleagues, but we can no longer allow poor epigenetics studies to be given credibility if this field is to survive. By ‘poor,’ I mean uninterpretable.”

“This is only representative of the broader literature,” he told me. “The problems in the field are systematic. We need to change how epigenomics research is performed throughout the community.”

Complete Article HERE!