Archive for 'Arts and science'

Two Heads (One of Them Real) Are Somewhat Better Than One

Thursday, June 22nd, 2017

A new test of the old idea that apparently having a head at your rear might save your life, if you are a butterfly:

Two-headed butterfly vs. mantis: do false antennae matter?Tania G. López-Palafox and Carlos R. Cordero, PeerJ, vol. 5, 2017, e3493. The authors, at Universidad Nacional Autónoma de México, report:

“The colour patterns and morphological peculiarities of the hindwings of several butterfly species result in the appearance of a head at the rear end of the insect’s body…. We explored the role of hindwing tails (presumably mimicking antennae) in predator deception in the ‘‘false head’’ butterfly Callophrys xami. We exposed butterflies with intact wings and with hindwing tails experimentally ablated to female mantises (Stagmomantis limbata)…. [Our study indicates] that at least some aspects of the ‘false head’’ help C. xami survive some mantis attacks, supporting the notion that they are adaptations against predators.”

Why Are Bird Eggs Bird-Egg-Shaped? [New research from an Ig Nobellian]

Thursday, June 22nd, 2017

Mahadevan, who won an Ig Nobel Physics Prize in 2007 for studying how/why wrinkled sheets become wrinkled, has a new study out about how/why bird eggs become bird-egg shaped. The study, by Mahadevan and several collaborators, is:

Avian Egg Shape: Form, Function, and Evolution,” Mary Caswell Stoddard, Ee Hou Yong, Derya Akkaynak, Catherine Sheard, Joseph A. Tobias, and L. Mahadevan, Science, vol. 356, no. 6344, June 23, 2017, pp. 1249-1254. Here’s a bit of detail from it:

Ed Yong, writing in The Atlantic, savors the new paper:

Think about an egg and you’ll probably conjure up an ellipse that’s slightly fatter at one end—the classic chicken egg. But chickens are outliers. Hummingbirds lay eggs that look like Tic Tacs, owls lay nigh-perfect spheres, and sandpipers lay almost conical eggs that end in a rounded point. After analyzing hundreds of species, Stoddard showed that the most common shape—exemplified by an unremarkable songbird called the graceful prinia—is more pointed than a chicken’s.

“We mapped egg shapes like astronomers map stars,” Stoddard says. “And our concept of an egg is on the periphery of egg shapes.”

Beyond displacing chickens as the Platonic ideal of egg-dom, Stoddard’s data also helped her to solve a mystery that scientists have debated for centuries: Why exactly are eggs shaped the way they are?…

To solve it, Stoddard teamed up with L. Mahadevan, a biophysicist at Harvard University who has studied “how leaves ripple, how tendrils coil, and how the brain folds, among other things.” He realized that all eggs could be described according to two simple characteristics—how asymmetric they are, and how elliptical they are. Measure these traits, and you can plot every bird egg on a simple graph. They did that for the eggs of 1,400 bird species, whose measurements Stoddard extracted from almost 50,000 photos…

The Los Angeles Times report about this includes an appraisal by Charles Deeming, who himself was awarded a 2002 Ig Nobel Biology Prize for co-authoring the study “Courtship Behaviour of Ostriches Towards Humans Under Farming Conditions in Britain.” The LA Times writes:

Charles Deeming, an ecologist who studies bird reproduction at the University of Lincoln in England and who was not involved in the study, said that pelvis shape, in particular, could be critical in determining egg shape. With further research, he said, scientists may be able to narrow down a more specific link between bird anatomy and egg shape.

Eggs (spinning) in milk – study

Monday, June 19th, 2017

Have you ever wondered why a hard-boiled egg, or a pool ball, spinning on a countertop and passing through a puddle of milk, draws milk up the side of the egg and then ejects it at the maximum radius? So did Ken Langley, Jeff Hendricks, Matthew Elverud, Dan Maynes and Tadd Truscott of Brigham Young University, US.

A hard-boiled egg spinning on a countertop and passing through a puddle of milk draws milk up the side of the egg and then ejects it at the maximum radius. This same phenomenon occurs for any partially submerged spinning object whose radius increases upward from the fluid surface (e.g., spheres, inverted cones, rings, etc.). In particular, spheres are used to investigate the behavior of this phenomenon and its sensitivity to experimental parameters. Three modes of ejection — jets, sheets, and sheet break-up — are identified, which are highly dependent on several parameters: viscosity, angular velocity, immersion depth of sphere, and sphere diameter. Experimental results are presented with comparisons to a theoretical model that is derived using integral conservation of momentum. This phenomenon can be used as a pump to easily remove fluids from shallow areas.”

See: ‘Eggs in Milk: The Conclusion’ presented at the 64th Annual Meeting of the APS Division of Fluid Dynamics, Volume 56, Number 18, , 2011. Further details of the investigation, including the photo above, are provided by Tadd Truscott.


The Theory That Lesbians Evolved to Please Men [research study]

Thursday, June 15th, 2017

Researchers in Cyprus gathered info about men’s sexual desire for lesbians. Then, having satisfied their desire to collect that info, the researchers explained what it means to them. The study is:

The evolution of female same-sex attraction: The male choice hypothesis,” Menelaos Apostolou [pictured here], Marios Shialos, Michalis Khalil, and Vana Paschali, Personality and Individual Differences, vol. 116, 2017, pp. 372–378.

The authors, at the University of Nicosia, Cyprus, explain: “this paper proposed a theoretical framework where, during the period of human evolution, same-sex attractions in women were under positive selection. The source of positive selection has been male preferences for opposite-sex sex partners who experienced same-sex attractions.”

Apostolou, Shialos, Khalil, and Paschali gathered data: “This theoretical framework was used to generate four predictions that were tested in two online studies which employed a total of 1509 heterosexual participants. ”

Apostolou, Shialos, Khalil, and Paschali explain that the data confirms their expectations about what some men find sexually attractive about some women sometimes:

“It was found that… a considerable proportion of heterosexual men desired partners who experienced same-sex attractions. In addition, it was found that men were more sexually excited than women by the same-sex infidelity of their partners, and they desired more than women, their opposite-sex partners to have sex with same-sex individuals. Finally, participants’ preferences were contingent on the seriousness of the relationships, with same-sex attraction to be preferred more in short-term than in a long-term partner.”

Apostolou, Shialos, Khalil, and Paschali arrive at a new understanding about evolution:

“These findings were employed in understanding the evolutionary origins of same-sex attraction in women…. Men’s desire for women who are attracted to other women selects for women who are attracted to other women. In turn, male desires, along with factors such as arranged marriage, which weakened the negative fitness costs of same-sex attraction, can explain the relatively high frequency of this trait in the population.”

BONUS: The newspaper El País supplies its own interpretation of this study, pointing out that “no homosexual woman has been interviewed in this study.”

Schmutz: White Wine Invites Melanoma, and Coffee Discourages It?

Thursday, June 15th, 2017

Drinking alcohol — specifically, drinking white wine — may increase your change of getting melanoma, but drinking coffee may decrease your chance. That’s what this new study suggests. The study does not suggest, though we do, that you spend a few minutes exploring the ways that someone might find seemingly interesting things by the process known as “torturing the data.”

Here is the study: “Mélanome: alcool ou café, il faut choisir [Alcohol or coffee to help keep melanoma at bay],” Jean-Luc Schmutz, Annales de Dermatologie et de Vénéréologie, 2017. The author is at Hôpital de Brabois, Vandœuvre-lès-Nancy, France.

Here is Doctor Schmutz: