Warring sexes

Both Twisty and Amanda seem a bit weirded out by this news that the fetus can be viewed as a kind of parasite. This story has been around long enough that a lot of us just take it for granted—I wrote about the example of preeclampsia a while back.

There are worse feminist-troubling theories out there, though. In particular, there is the idea of intersexual evolutionary conflict and male-induced harm. In species where there is some level of promiscuity, it can be to the male’s evolutionary advantage to compel his mate to a) invest more effort in his immediate progeny, b) increase her short-term reproduction rate, and c) suppress her ability to mate with other males. After all, his optimal strategy is to flit from female to female, copulate, and put her to work producing his offspring. The female’s preferred strategy, on the other hand, is to take her time, maximize her lifetime reproduction rate, and select the best genetic endowment for her children.

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This sets up a cycle of counter-adaptations in the population. If a male acquires a mutation that increases his fitness at the expense of his mate’s—for instance, if some component of his semen works on her brain to suppress her interest in remating—it will spread through the population due to its positive effect on male fitness, even though it reduces female fitness. Subsequently, a female who acquired a counter-adaptive resistance to the male’s hormonal sabotage would have an advantage, and that gene would spread through the population, reducing male fitness by making them less capable of controlling female reproduction. Then, of course, males could evolve some other sneaky way of maximizing their reproduction rate—vaginal plugs, secretions that make the mated female unattractive to other males, proteins that put her ovaries into overdrive to produce more eggs now at the expense of the female’s long term survival.

It all sounds improbable and dystopian, but all of these mechanisms and more have been observed in that exceptionally promiscuous species, Drosophila. Drosophila seminal fluid has the property of reducing the female’s interest in remating, increasing her rate of egg-laying, and is also mildly toxic. Artificial selection in the lab can produce females that are resistant to the effects, and males that produce more and more potent semen to overcome their resistance, to the point where the line of “super potent” males, when crossed to unselected females, kill their partners with their ejaculations. There is literally a battle of the sexes in these species.

To speak up in my defense, though, not all males are evil exploitive pigs. The logic of this pattern of sexual competitiveness vanishes as species exhibit greater and greater monogamy—if you have only one mate, it is to your advantage to take good care of him or her, because a loss diminishes your reproductive fitness.


Rice WR (2000) Dangerous Liaisons. Proc. Nat. Acad. Sci. USA 97(24):12953-12955.

Rice WR (1996) Sexually antagonistic male adaptation triggered by experimental arrest of female evolution. Nature 381(6579):189-90.

I, for one, will welcome our Cyborg Insect overlords

Nah, I thought this has got to be a joke:

The Pentagon’s defence scientists want to create an army of cyber-insects that can be remotely controlled to check out explosives and send transmissions.

But no…there is actually a DARPA call for proposals.

DARPA seeks innovative proposals to develop technology to create insect-cyborgs, possibly enabled by intimately integrating microsystems within insects, during their early stages of metamorphoses. The healing processes from one metamorphic stage to the next stage are expected to yield more reliable bio-electromechanical interface to insects, as compared to adhesively bonded systems to adult insects. Once these platforms are integrated, various microsystem payloads can be mounted on the platforms with the goal of controlling insect locomotion, sense local environment, and scavenge power. Multidisciplinary teams of engineers, physicists, and biologists are expected to work together to develop new technologies utilizing insect biology, while developing foundations for the new field of insect cyborg engineering. The HI-MEMS may also serve as vehicles to conduct research to answer basic questions in biology.

The final demonstration goal of the HI-MEMS program is the delivery of an insect within five meters of a specific target located at hundred meters away, using electronic remote control, and/or global positioning system (GPS). Although flying insects are of great interest (e.g. moths and dragonflies), hopping and swimming insects could also meet final demonstration goals. In conjunction with delivery, the insect must remain stationary either indefinitely or until otherwise instructed. The insect-cyborg must also be able to transmit data from DOD relevant sensors, yielding information about the local environment. These sensors can include gas sensors, microphones, video, etc.

Although the idea of having a remote controlled dragonfly is very cool, I am very pessimistic, and have to dash a little cold water on the plan.

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Linkage

I must purge the mailbox of a few worthy links…so here they are.

There are a couple of calls for submissions:

A few carnivals I failed to mention this week:

Freethought Filter is back up and running again!

Darksyde addresses the Fermi “paradox”. I don’t think it’s a paradox at all, and that the answer from his list is the rarity solution.

News from Enceladus

There were all kinds of rumors today (from Drudge, of all places) that NASA was going to announce some major discovery related to life elsewhere in the solar system. While that would be incredibly cool, I was dubious—anyone remember the Martian “bacteria”? NASA has a rather poor reputation for this sort of thing.

Anyway, Bad Astronomy has the actual news: it’s interesting, but the media blew it way out of proportion. Plumes of water (they think) have been observed on Enceladus, a moon of Saturn.

I’d be more enthused if the earlier hype hadn’t switched on my skeptical gland and flooded my system with cyniclin, the hormone of disillusionment.

Snuppy is a real clone!

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Remember Snuppy, the cloned puppy? He’s been living under a cloud for a while now, since one of his creators was Woo-Suk Hwang, the Korean scientist who was found to have faked data and exploited his workers, and there was concern that perhaps the dog cloning experiment was also tainted.

Put those fears to rest. Two groups of researchers have independently analyzed Snuppy and its putative clone parent, and both agree that it is most likely a clone. The nuclear markers between the two were identical, while mitochondrial markers were different—exactly what you’d expect in this kind of clone, and not what you’d see from simple twins, for instance, or if someone had faked the samples.


Parker HG, Kruglyak L, Ostrander EA (2006) DNA analysis of a putative dog clone. Nature 440:E1-E2.

Seoul National University Investigation Committee, Lee JB, Park C (2006) Verification that Snuppy is a clone. Nature 440:E2-E3.

Hug a high school teacher today!

My morning was spent at the local high school today, talking to the biology classes about the evidence for evolution. This wasn’t in response to any specific worries—in fact, talking to the instructor, it’s clear that they’re doing a decent job of covering the basic concepts here already—but that my daughter is in the class, and she thought it would be fun to have her Dad join in the conversation. I will say that it was very obliging of the Chronicle of Higher Ed to publish this today:

In a packed IMAX theater in St. Louis last month, a middle-school teacher took the stage and lectured some of the leaders in the American scientific establishment. In a friendly but commanding style honed by three decades in the classroom, Linda K. Froschauer told scientists that it was time for them to get involved in elementary and secondary education.

“Go home. Identify science teachers in your own neighborhood. Offer to help them,” she said. “Go to the board of education and speak up.”

Excellent advice! It gives an overworked teacher a brief break, lets you see what’s going on in the classrooms, makes the students a little more familiar with college faculty, and maybe it makes a few of them think and gives them a tiny bit more background. It was generally a very positive experience, although it does make me appreciate the work our secondary ed teachers have to do.

I gave a very informal lecture in which I confronted the whole ‘controversy’ about humans evolving from apes. I brought along a few transparencies and a human skull, and gave them an overview of three lines of evidence: transitional fossils, similarities in genes and chromosome structure, and “plagiarized errors”. I kept it fairly simple, using little of the technical vocabulary and defining what little I had to use, but tried to introduce some important concepts, like the taxonomic hierarchy and diagnostic characters and repetitive DNA and pseudogenes. I was also impressed that the students asked good questions, so I think they were grasping what I was talking about.

Boy, but high school teachers have a very different burden than I do. Having to give the same talk 3 times in a row is challenging—I was getting bored with me! The students also range in ability and interest far more than I’m used to…there were many who were attentive and curious (more than I’d expected, which is a very good sign), and there were some who were bored and rather disruptive (but not as many as I’d feared.) I tried not to completely neglect the troublemakers and engaged them a few times with questions, but I had it fairly easy since the regular teacher was there to hover over them and keep them in line. There’s a bit of drill sergeant rigor required in high school teachers that I don’t need at the university as much, I think.

I’d do it again, gladly…as long as I’ve got a few weeks to recover between days at the high school. The grade schools are where we have the most need to get more science into play anyway, so it feels like a productive birthday for me when I can talk to a few 10th graders. And any high school teachers out there—you’re doing an important job, and those of us up in the ivory tower of the university really do care about what’s going on in our schools. Don’t be shy about asking your local college science departments if we’d be willing to contribute in your classroom, I think there is a fair number of us who’d be happy to share our perspective.

PZ Myers’ Own Original, Cosmic, and Eccentric Analogy for How the Genome Works -OR- High Geekology

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I’m teaching my developmental biology course this afternoon, and I have a slightly peculiar approach to the teaching the subject. One of the difficulties with introducing undergraduates to an immense and complicated topic like development is that there is a continual war between making sure they’re introduced to the all-important details, and stepping back and giving them the big picture of the process. I do this explicitly by dividing my week; Mondays are lecture days where I stand up and talk about Molecule X interacting with Molecule Y in Tissue Z, and we go over textbook stuff. I’m probably going too fast, but I want students to come out of the class having at least heard of Sonic Hedgehog and β-catenin and fasciclins and induction and cis regulatory elements and so forth.

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Swamps are lovely

Darksyde’s latest Science Friday is an interview with Michael Grunwald on the subject of the Florida Everglades. It’s a mostly bad news with threads of forlorn hope scattered throughout, like most environmental news.

The bad news is that the ecosystem is in a state of near-collapse. Lake Okeechobee is going to hell; it’s the color of espresso. The Caloosahatchee and St. Lucie estuaries are just gross. And CERP is already way over budget, behind schedule, and off track; Congress is losing interest in funding it. The good news is that there are signs that Floridians are beginning to recognize that their way of life is not sustainable. Posh towns like Fort Myers, Sanibel, Stuart and Jupiter are in revolt over the decline of the estuaries; retirees are having trouble breathing at the beach. Governor Bush shocked enviros by taking their side in a battle over sprawl in Miami-Dade County. A plan to build a massive biotech campus at the edge of the Everglades–maybe the biggest project in Florida since Disney–was blocked by an environmental lawsuit; now it looks like it’s going to move to a more sensible location. And remember: several million acres of the Everglades ecosystem is already in public ownership. So there’s hope.