Sex roundup: Affirmative action in animal research
My list of potential topics is heavy with sex this week. First–and possibly most far-reaching–the National Institutes of Health is coming to grips with the fact that males and females are . . . different. They react differently to drugs, for instance. And that means that research results from one are not necessarily trustworthy for both.
To be fair, let us note that NIH changed the rules to even up the sex ratio in human research some years ago. Today the agency brags that more than half of research participants in human studies are female.
Until now, though, that affirmative action has not applied to studies with lab animals. It’s possible that decades worth of animal research has been skewed by the fact that female lab animals have been routinely eliminated from research. One reason given: their raging hormones make interpreting results messy. See Susannah Locke’s post at Vox explaining the kinds of problems the present system has created.
The agency is writing new animal research guidelines for NIH-funded researchers; they will be released in phases beginning late this year. Researchers will be required to include both sexes in their animal experiments, and to include them in large enough numbers to detect sex differences in the results. Grant reviewers will be instructed to take lab animal sex balance into consideration when considering a proposal. Those who work with cells will be encouraged to use both kinds too, but the rules for cells seem a little more, um, flexible.
Even some researchers who thoroughly approve of organizing a piece of research so that it’s possible to sort out any effects that differ by sex have been made gloomy by this announcement. As Drug Monkey explains, it will increase research costs, and by more than just doubling the costs.
“Let me be clear, I want to do sex-differences studies. I am delighted that this will be a new prescription. I agree with the motivating sentiments. . . What it takes is additional grant funding. Or tolerance on the part of P&T committees, hiring committees and grant review panels for apparently reduced progress on a scientific topic of interest.”
Sex roundup: Researchers have been ignoring vaginas, too
Turns out that female reproductive machinery has been excluded from research along with female lab animals and female cells. Researchers from Europe and Australia report in PLOS Biology that they looked at 25 years’ worth of studies on the evolution of genitals–an increasingly hot topic–and found that just under half, 49%, report on male genitalia only. (44% studied genitalia of both sexes and 8% females only.)
Like the objection to disproportional attention to males in lab animal research, this is a complaint that has nothing at all to do with sexual politics. It’s about how to design studies that don’t skew results and lead to false conclusions.
Some of this may be, if not exactly sexual politics, a hangover from previous centuries: the idea that females are passive recipients of male sexual attention, with few genital features to excite research interest. But a big part of this neglect is because female genitalia are a lot more difficult to study. Male apparatus is usually out there for all to see; female genitalia are more often internal. Elizabeth Gibney reports at the Nature Newsblog that the data support this idea. Female creatures with external genitalia–spiders, for example–are not nearly as neglected by researchers.
At Not Exactly Rocket Science, Ed Yong agrees. A tube, he says, is easier to study than a cavity. But he also thinks old-fashioned (and erroneous) ideas about female passivity during sex linger and divert research attention. He’s got lots of fascinating details from animals to show that females often control, for instance, the ease of mating (in ducks) and the choice of male sperm (in earwigs.)
Sex roundup: Risky older fathers, another flub from Nate Silver’s 538
Knight Science Journalism Tracker Paul Raeburn takes issue with a piece at Nate Silver’s fivethirtyeight.com asserting that tales of birth defects, autism, and other psychiatric and behavior disorders associated with older fathers are overblown. He argues that the piece entirely ignores a crucial paper, a 2012 study from deCODE Genetics showing that the older they get, the more likely men are to pass mutations on to their children.
The 538 piece is by Emily Oster, who at the moment is looking like the only member of the 3-person 538 science staff who’s writing regularly. Most of the work so far posted in the 538 science section is from outsiders, not all of them writers.
Oster is an economist at the University of Chicago, but has been producing a weekly piece of science writing in debunkery mode. I wrote about Nate Silver’s new 538 in March, and my post was partly about another Oster piece. This was a contrarian take on whether acetominophen during pregnancy has long-term consequences for children. I liked some of what she said, especially her emphasis on how science writers so routinely give readers misleading impressions of a study by reporting relative risk figures instead of absolute numbers. But, given the small amount of data she analyzed, I thought the piece was waaaay too long.
The paternal age piece is also quite long, but at least Oster does additional analysis of the data she considers. Which is good, because data is supposed to be what 538 is about. OTOH, not good if she’s leaving out essential data such as the deCODE paper Raeburn describes.
As I write, there are now two confirmed US cases of MERS, the new Middle East Respiratory Syndrome coronavirus, which has been fatal in somewhere between a quarter and a third of cases. Both US cases are imports, unrelated to each other, one diagnosed in Indiana and the other in Florida. Both occurred in healthcare workers traveling here from Saudi Arabia, which has been the chief locale of MERS cases.
The disease is not hugely contagious; it appears to require sustained close contact, as with hospital workers or family members caring for a sick relative. The World Health Organization has issued official reassurance: this is not a global public health emergency. Or at least not yet. Find this news in several places, including Physician’s First Watch (from the New England Journal of Medicine). First Watch is also making its archive of MERS articles, a couple of dozen at this point, available free here.
Find exhaustive detail as of last Tuesday at the Centers for Disease Control’s Morbidity and Mortality Weekly Report. Health authorities expect more imported cases of MERS. Jason Beaubien reports at Shots that American hospitals are taking steps to recognize MERS early and keep it from spreading.
Where the virus comes from and how it infects people are uncertain. Its primary source is thought to be the Egyptian tomb bat, an appropriately sepulchral name. I haven’t been able to find out why this animal’s common name is tomb bat. But reportedly it likes to nest in stone structures, so maybe that’s it. It’s a fruit bat, like the bat reservoir for another scary coronavirus, SARS.
The virus has spread to camels, now suspected of being its intermediate host. A Lancet paper from last fall found antibodies to the virus in some camel populations but not others. The virus itself has been recovered from the noses of Saudi Arabian dromedary camels. (That’s the one-hump kind.)
Laurie Garrett, a long-time and highly decorated science writer who specializes in infectious disease, tells us at Foreign Policy that the geographic range of infected camels “perfectly overlaps the North African terrain of Egyptian tomb bats.” This could mean, she speculates, that sporadic human MERS disease may have occurred in the Middle East, unrecognized, for centuries.
Some MERS patients had contact with camel meat or milk before they fell ill, but camels appear to be involved in only a small number of MERS cases. Which means, Garrett says, “the vast majority of MERS cases seem to have been acquired by other means.”
For a thorough overview of the MERS story so far, see Judy Stone’s post at her SciAm blog Molecules to Medicine. She and Laurie Garrett both delve into the politics of MERS. The Saudi Arabian authorities in particular are tight-fisted with information. A scientist there was fired for sending a saliva sample to the Netherlands for analysis.
The genetics of race
Science writer Nicholas Wade, late of the New York Times, has a new book out about the genetics of racial classification. Race, it argues, is not a social construct; races are genetically real and it’s time we learned to live with that fact. I reviewed the book this week at the Genetic Literacy Project. A Troublesome Inheritance: Genes, Race and Human History is impressively researched and will tell you things you didn’t know even if you know a lot.
My chief complaint is that, although Wade pays lip service to the reality that nongenetic factors loom large in human evolution and human development and human life, sometimes he doesn’t seem to believe it. That’s particularly evident in Chapter 7, where he endorses the work of economic historian Gregory Clark.
Clark argues that Brits underwent something of a personality change between 1200 and 1800 because the rich reproduced more than the poor. This resulted in reduced interpersonal aggression and national embrace of virtues like thrift and the work ethic.
Wade believes this was due to the genes of the rich. He produces no evidence for these behavioral genetics influences, however. He simply asserts them, a bad move for a science writer. Given what we know at the moment about these virtuous genes, which is nothing, it’s just as plausible that these changes were shaped by parental habits and cultural inculcation. More detail, and more argument (about this and other evolutionary topics), in my review.