scigirl

Boring scigirl here...

Correlation does not mean causation. Blah blah blah. . .

However if the correlation is indeed valid, than it is interesting to wonder what the confounding variable is. I'm also wondering, on behalf of a man in a red bow tie... Does this theory apply to the quality of sperm facials as well?

scigirl

Jeremy Pallant

My first thought on seeing the subject was that.

Edited to add...

I see I just broke 900 posts. Only took me 2.5 years.

Gurdur

uh huh, uh huh uh huh uh huh

ps418

I read a paper yesterday in Behavioral Ecology (Cratsley and Lewis, 2003) that demonstrated a very similar female preference relationship in the firefly Photinus ignitus. I couldn't help but notice the similarities.

The paper demonstrates first that females of P. ignitus have a strong preference for males with longer flash durations. The range of flash durations was 56 to 123 ms, with 90% of the flies displaying flashes between 56 and 89 ms. Females were shown to prefer flash durations at the high end of the distribution. Beyond the range of flash duration typical of their species, however, female responsiveness drops. The females also have a preference for brightness, but are not able to distinguish between absolute brightness and relative brightness, i.e. they will respond to a not-so bright local fly, with greater relative brightness, than to an absolutely brighter fly who is further away and so looks dimmer from the female's perspective.

The second thing that the paper demonstrates is that, just as facial characteristics predict sperm motility and morphology in humans, the flash duration in male fireflies predicts quite well the size of their spermatophore (which contains both sperm and nutrients). In fact, flash duration was found to predict spermatophore size significantly better than did body mass or lantern dimensions. Cratsley and Lewis (2003) write that "[b]ecause adult Photinus fireflies do not feed in the field (Lloyd, 1997; Williams, 1917), male spermatophores may represent the only nutritional supplementation that females receive as adults. Therefore, females are expected to show preference for any male traits correlated with large spermatophores."

You can read the press release, or the paper itself:

Cratsley, C.K. and S.M. Lewis. (2003) Female preference for male courtship flashes in Photinus ignitus fireflies. Behavioral Ecology 14,135–140. PDF file

Patrick