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Posts Tagged ‘sexual selection

“Not with a bang, but with a whimper”*…

 

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Death Table from Tuberculosis in the United States, prepared for the International Congress on Tuberculosis, September 21 to October 12, 1908. Image: U.S. National Library of Medicine

 

Recent history tells us a lot about how epidemics unfold, how outbreaks spread, and how they are controlled. We also know a good deal about beginnings—those first cases of pneumonia in Guangdong marking the SARS outbreak of 2002–3, the earliest instances of influenza in Veracruz leading to the H1N1 influenza pandemic of 2009–10, the outbreak of hemorrhagic fever in Guinea sparking the Ebola pandemic of 2014–16. But these stories of rising action and a dramatic denouement only get us so far in coming to terms with the global crisis of COVID-19. The coronavirus pandemic has blown past many efforts at containment, snapped the reins of case detection and surveillance across the world, and saturated all inhabited continents. To understand possible endings for this epidemic, we must look elsewhere than the neat pattern of beginning and end—and reconsider what we mean by the talk of “ending” epidemics to begin with…

Contrary to hopes for a tidy conclusion to the COVID-19 pandemic, history shows that outbreaks of infectious disease often have much murkier outcomes—including simply being forgotten about, or dismissed as someone else’s problem: “How Epidemics End.”

* T. S. Eliot, “The Hollow Men”

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As we contemplate the end, we might send insightful birthday greetings to Nettie Maria Stevens; she was born on this date in 1861.  A geneticist– and one of the first American women to achieve recognition for her contributions to scientific research– she built on the rediscovery of Mendel‘s paper on genetics (in 1900) with work that identified the mechanism of sexual selection: its determination by the single difference between two classes of sperm—the presence or absence of (what we now call) an X chromosome.

220px-Nettie_Stevens source

 

“For she had eyes and chose me”*…

 

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Psychologist David Perrett’s… Perception Lab recruited 300 men and 400 women, all of whom had heterosexual partners and had been raised by two parents. They learned that romantic partners tend to look alike — the participants and their partners tended to have similar hair color and similar eye color.

This might be explained by a self-similar preference or narcissism, but on looking deeper into the data Perrett’s team found that the single best predictor of one’s partner’s eye color was the eye color of one’s parent of the opposite sex. If a woman’s mother had blue eyes and her father had brown eyes, she would most likely be partnered with a brown-eyed man. If a man’s mother had blue eyes and his father had brown eyes, his partner most likely had blue eyes. Similarly, the hair color of a man’s mother was the single best predictor of his partner’s hair color. “These results indicate that individuals choose partners who resemble their opposite-sex parent both in eye and hair color.”…

The mysteries of human attraction: “Eye to Eye.”

Read the underlying paper: Anthony C. Little et al., “Investigating an Imprinting-Like Phenomenon in Humans: Partners and Opposite-Sex Parents Have Similar Hair and Eye Colour,” Evolution and Human Behavior 24:1 [2003], 43-51.

* William Shakespeare, Othello

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As we peer through the window to the soul, we might spare a thought for playwright, poet, artist, biologist, theoretical physicist, and philosopher Johann Wolfgang von Goethe; he died on this date in 1832.  Probably best remembered these days for Faust, he was “the master spirit of the German people,” and, after Napoleon, the leading figure of his age.

In 1810, Goethe published his Theory of Colors (Zur Farbenlehre), which he considered his most important work.  In it, he contentiously (and incorrectly) characterized color as arising from “the dynamic interplay of light and darkness through the mediation of a turbid medium.”  Still, Goethe was the first systematically to study the physiological effects of color; his observations of the effect of opposed colors led him to a symmetric arrangement of his color wheel, “for the colors diametrically opposed to each other… are those which reciprocally evoke each other in the eye.”  Indeed, after being translated into English by Charles Eastlake in 1840, his theory became widely adopted by the art world, most notably by J. M. W. Turner.

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Written by LW

March 22, 2020 at 1:01 am

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