I’ve spent so much time talking about anti-science that I’ve forgotten to mention why I do it. Of course, I can give the grandiose reply; that science is the route to every improvement to human life to date. However while this is true, in reality I find science absolutely amazing! Nothing in any work of fiction compares to the strangeness that is reality.
Science blows my mind!
So, to remind myself of this fact, I plan to create an ongoing series where I briefly mention the latest studies that I’ve come across that I thought were pretty amazing.
Moths vs bats: fighting fire with fire!
In the July 2013 Biological Letters, there is an article by Barber and Kawahara (doi: 10.1098/rsbl.2013.0161) where they took three different species of hawkmoths and tested them with touch and playback of ultrasonic bat calls (used by for echolocation).
Each of these species responded to these actions by producing a completely ultrasonic call in return!
They found that the mechanism for this with the males were diamond-shaped scales that they would rub against their abdomen. As these scales were part of the reproductive structure, the mechanism would be different in the females of these species, as they too were able to produce ultrasonic sounds, although how females did this was not discovered.
While the function of this response is not yet know, the authors suggest that it might play a similar role to the ultrasonic sounds produced by the tiger moth; that is, to startle, warn or, coolest yet, jam the bat’s own sonar!
Who would have thought Galactic Sci-fi was actually being played out for real in our own back yards?
Social Learning in Fairy-wrens
This one is closer to my undergrad days, where I did a few studies on assemblage and more directly, animal behaviour; in my case it was a small allodapine bee species and their parasitic counterpart, both native to the Dandenong Ranges.
In Feeney and Langmore (2013), the researchers explored the ability of fairy-wrens to learn about a threat, in this case the a cuckoo species, via social learning.
The method they used was to expose naive members of a social group to a dummy cuckoo when they were by themselves, then again when with their group – with members aware of the potential threat cuckoos present – and then a final time when the previously naive member was alone and record the response.
They carried out the same test with a dummy honey eat, which poses no threat to the fairy-wrens, as a control.
The researchers found that naive members would learn about the threat through the behaviour of the group and would respond in kind with later appearances of the cuckoo!
We’ve all heard about how clever various parrots, ravens and crow species can be – even the currawong is also known for using tools (although less people have heard of this genus) – but I think it’s pretty cool that such a little bird (in my humble opinion, comparable in shape and size to a golf ball with a tail, but of course, more striking with its flashes of vivid blue within black and white) can learn from its peers!
It just goes to show that the minds of other species are more complex than we tend to give them credit for.
Beauty may indeed be in the eyes of the beholder, however the beholder is the result of evolutionary pressures. Facial beauty seems to be universal and beyond cultural preferences.
So why do we find one face more attractive than another?
Previous work has found a relationship between the attractiveness of a male face and the strength of his immune response to hepatitis B. Rantala et al (2013) explored whether the same would be found for females.
The researchers took photos of young Latvian females and collected data on their immune response to hep B, cortisol level (the hormone released due to stress) and percentage of body fat. They then had Latvian men rate the attractiveness of these faces for analysis.
Unlike when the test was was carried out on male faces, they found that a strong immune response did not predict how attractive a female face was. Instead, both cortisol levels and body fat better predicted female face attractiveness.
Stress, that is the amount of cortisol present, was negatively related to attractiveness; a finding that matches previous male tests. Faces that were were either ends of the body fat measure – either too thin or too fat – were also negatively associated with facial attractiveness.
Both stress and over/under weight can impact on fertility as well as susceptibility to disease and other health issues, which the author suggest provide the evolutionary motive.
Most importantly, the authors demonstrate something many people have been saying for years; the unrealistically thin woman that magazines splash before young woman – telling their readers what they ought to aspire to – is simply NOT attractive. Attractiveness is found in a healthy size, a happy smile and positive mindfulness.