All this talk about choice makes me want to clobber certain blurb writers

Why Girls Sleep Around: The Evolutionary Case for Female Promiscuity

In a study of mouse-like marsupials, “survival of babies with promiscuous mothers was almost three times as high as those in the monogamous group.” Key reasons: 1) “The sperm of some males were far more successful than others.” 2) “Babies fathered by these males were twice as likely to survive.”

Takeaway for women: “Polyandry improves female lifetime fitness.” Takeaway for men: “Males with more competitive ejaculates sire more viable offspring.” Fine print: “Males usually died after a short and intense single mating season due to exhaustion and aggressive encounters with other males.

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Let’s think about the biological reasons why it’s inaccurate to imply this finding can be extrapolated across species (and thus suggest all females have somehow selected to be more promiscuous). Most of my rationale has to do with the idea there are…well, ridiculously huge differences in the life history traits and mating strategies employed by humans and small marsupials, to name just two animals.  Polyandry, the mating with multiple males by females, improves female lifetime fitness for semelparous species—organisms with high adult mortality that blast the world with offspring shortly before they die, like cicadas, salmon and the antechinuses mentioned here. That’s the only chance at reproductive success they get, and more importantly there’s no parental care involved. In contrast, humans are iteroparous and invest much more energy in the survival of a few periodic offspring. So popping out 3 times as many kids at once would actually decrease lifetime fitness, because it’s likely to kill off or otherwise take an energetic toll on the mother on which the young depend. You have your zillion offspring, but they won’t survive. The relationship between increased mating and healthier babies doesn’t hold.

On the bright side, the fine print doesn’t apply to humans either, because sperm competition in iteroparous species is comparatively less fierce. In other words, guys don’t spend so much energy in their one mating session that they die right after it. (Because, we hope, they get more than a single try.) Not so the case for these marsupials: “Male antechinuses copulate for 5–14 consecutive hours with each female, and ejaculate around 3 h after mating starts. This extraordinary male reproductive biology could subject sperm to extreme physiological and epigenetic stress, resulting in the marked relationship between male sperm competitive ability and offspring viability” (Fisher et al. 2006, yes I actually went and found the article and am citing it in a USP blog post).

So HA, Slate! You and your sensationalist, insinuating headlines can take a backseat to breeding biology!

Although antechinuses are still really cute.

—Irene L.

Possible symposium thoughts

I was thinking about how I could convert some of the work I’m already doing (i.e. working in a neuro lab looking to repurpose Alzheimer’s drugs for glaucoma) to something relevant to the Two Cultures for the symposium.  One thought I had was that we needn’t limit ourselves to just the two cultures discussed in the paper (“scientists” and “humanities”/”everyone else”).

For my field, there’s actually a lot of interplay between scientists and the lay public.  In particular, the people making drugs/searching for new drug candidates/hoping to explain how or why drugs do or don’t work attempt to get grants from foundations (I’m talking something outside of NIH or NSF here; local foundations like the “Cure Huntington’s Disease Initiative” offer HUGE sums of money to labs pursuing ideas they deem worthy, whereas other smaller ones like local Autism foundations offer a precious few thousand to eager labs) that may not be scientifically-minded.  It’s quite an experience – and I suppose one could say it’s interdisciplinary – to work with people outside the field and even outside of science in general while fundamentally addressing a single goal.

While Science vs Public is related to Snow in a straightforward way, we could expand further on that idea.  There are multiple “cultures” (‘modes of thought”, “theories”, actual cultures) in virtually every discipline, and focusing on a literal interpretation of the phrase ‘Two Cultures’ may open up the discussion to some of you in history/polysci/other fields.  That way, we might also add in variety and avoid getting too stuck discussing Science vs Humanities.

My ideas aren’t complete yet, but my telephone is ringing and so I’m going to post this and be off.

Just my two cents,

Melissa G