Happy Wednesday, April 1st, everyone!

Today, my picks for EvoLiteracy News are summarized in the following questions: Do liberal politicians smile more sincerely (= genuine happiness) than conservative politicians (= apparent happiness)? Does growing up in a deprive-from-resources environment (poverty) affect human brain development? How do sexual and natural selection interact when driving the evolution of plumage-coloration in birds? Below are the answers. Plus, don’t forget to visit the Photography Page of Evolution Literacy, which includes images of wildlife, landscapes, museums, monuments and cities from many countries, go to EvoLiteracy Photos.

Liberal Politicians Smile Sincerely… Conservatives Not So Much. Conservatives report, but liberals display, greater happiness. Science Magazine.

Wojcik et al. (total of 5 coauthors) summarize their study as follows: “Research suggesting that political conservatives are happier than political liberals has relied exclusively on self-report measures of subjective well-being. Wojcik et al. show that this finding is fully mediated by conservatives’ self-enhancing style of self-report and then describe three studies drawing from “big data” sources to assess liberal-conservative differences in happiness-related behavior. Relative to conservatives, liberals more frequently used positive emotional language in their speech and smiled more intensely and genuinely in photographs. The results were consistent across large samples of online survey takers, U.S. politicians, Twitter users, and LinkedIn users. Wojcik et al. findings illustrate the nuanced relationship between political ideology, self-enhancement, and happiness and illuminate the contradictory ways that happiness differences can manifest across behavior and self-reports.” See study in Science Magazine.

Poverty Does Affect Brain Development. Family income, parental education and brain structure in children and adolescents. Nature Neuroscience.

Noble et al. (total of 25 coauthors) write: “Socioeconomic disparities are associated with differences in cognitive development. We investigated relationships between socioeconomic factors and brain morphometry, independently of genetic ancestry, among a cohort of 1,000+ typically developing individuals between 3 and 20 years of age. Income was associated with brain surface area. Among children from lower income families, small differences in income were associated with relatively large differences in surface area, whereas, among children from higher income families, similar income increments were associated with smaller differences in surface area. These relationships were most prominent in [brain] regions supporting language, reading, executive functions and spatial skills; surface area mediated socioeconomic differences in certain neurocognitive abilities. These data imply that income relates most strongly to brain structure among the most disadvantaged children.” For access to complete article go to Nature Neuroscience.

Natural and sexual selection act on different axes [“directions”] of variation in avian plumage color. Science Advances.

Authors Peter O. Dunn, Jessica K. Armenta and Linda A. Whittingham summarize their research as follows: “The bright colors of birds are often attributed to sexual selection on males, but in many species both sexes are colorful and it has been long debated whether sexual selection can also explain this variation. Dunn et al. show that most evolutionary transitions in color have been toward similar plumage in both sexes, and the color of both sexes (for example, bright or dull) was associated with indices of natural selection (for example, habitat type), whereas sexual differences in color were primarily associated with indices of sexual selection on males (for example, polygyny [one male mating with several females] and large testes size). Debate about the evolution of bird coloration can be resolved by recognizing that both natural and sexual selection have been influential, but they have generally acted on two different axes [= “directions”]: sexual selection on an axis of sexual differences and natural selection on both sexes for the type of color (for example, bright or dull).” See complete article in Science Advances.

Dunn et al. explain that “Darwin’s theory of sexual selection was based on his observations of the bright colors of males, which he thought were preferred by females and led to a mating advantage for more colorful males. Wallace, on the other hand, pointed out that in many species, females are as ‘gay and brilliant’ as the male, and he suggested that dichromatism [the “two colors,” one in males, the other in females] evolved as a consequence of nest predation favoring more cryptic females.” The authors “examined both male and female plumage color in relation to 10 indices of natural and sexual selection to test whether dichromatism was primarily due to sexual selection, as Darwin proposed, whereas the color of both sexes was primarily due to natural selection [Wallace’s proposal].”

The Answer Is Both: Dunn et al. concluded that “Both natural and sexual selection have influenced the evolution of bird coloration, but in many respects, they have acted on two different axes [ = “directions”]: sexual selection on an axis of sexual differences and natural selection on an axis of color (for example, dull or bright) in both sexes. Thus, debate about the causes of variation in bird coloration may be resolved by recognizing that natural and sexual selection have generally acted on two different axes.” Science Advances.

Note: Sexual dimorphism driven by sexual selection is a wide spread phenomenon, documented in the fossil record; below, Parasaurolophus (male and female), a hadrosaurid dinosaur from the end of the Cretaceous (Art by Pavel Riha). The topic ‘sexual selection’ was addressed extensively by Charles Darwin in ‘The Descent of Man, and Selection in Relation to Sex‘ (1871), and by Alfred R. Wallace in ‘Tropical Nature, and Other Essays‘ (1878).

Reviews of Evolution Stands Faith Up: Reflections on Evolution’s Wars.

“…Shot-gun marriages between evolution and faith have never worked, despite the tradition of pointing the barrel at evolution’s head. The truth is that evolution likes it single. Free, with no stoppers of thought or restrains on logic. And when lured unknowingly into the altar by those who see facts and fiction compatible, evolution has consistently stood belief up and walked away, sometimes run, toward its secular turf… [The] dream of arranging evolution’s wedding with belief will remain dormant for as long as evolution is awake.” Provocative, intriguing, a contemporary and concise analysis of the clashes between science and faith: In this book, Guillermo Paz-y-Miño-C examines the societal sequels in public education, the future of America’s science and academia of believing in a deity. For this evolutionary biologist, educator and public speaker, “science is [the only] refined device for resolving ordinary curiosity and a powerful liberator of superstition. He thinks of science as “the subsistence kit to defeat re-emerging fundamentalism” in the world. With a journalistic style in short, yet documented essays, Paz-y-Miño-C encourages the reader to question “faith healing,” the “silly” forecast of Armageddon on two occasions in 2012 (after postponing the first engagement), or the “wrongly called” The God Particle, which scrambles fiction with facts. He considers “belief” to be a “disruptor,” which delays and stops the correct comprehension and acceptance of evidence. He alerts us about the threats of rejecting science, our African and ape evolutionary ancestry, and the epidemic growth of anti-intellectualism among decision makers, whose interest in replacing “curiosity-driven science” with profitable laboratory-bench work to secure sales of “science products” will drive the “culture of discovery in America” to vanish. But this author also contrasts his inner “frustration in attempting to reverse, at least around [his] immediate circle of influence, such trend…” with essays in which his contagious passion for science emerges. In his prose, Paz-y-Miño-C ignites our imagination to “take off from the roof of the Boston Museum of Science and its Charles Hayden Planetarium, while flying in a helicopter that, after metamorphosing into a spaceship, leaves Earth to immerse us into galactic infinitude.” Or to hike among sea lions, while they rest on the Galapagos shores, and feel as Darwin did the magnificence of nature. Or to contemplate the night sky from the top of the largest volcano in the World, Mauna Kea, in Hawaii, and accept the fact that, one day in the distant future, all its telescopes —or their remains— will drift away on their carrier, the late “Big Island,” and sink in the Pacific when the summit of Mauna Kea succumbs to erosion, hence following the drowning fate of the Hawaiian Islands. This open-ended book assures: “Once embraced by all, this truly universal language —scientific rationalism/empiricism and evolution— shall lead us to a more cohesive understanding of nature and of our amazingly diverse human condition. Humanity’s ultimate challenge will be to collectively embrace reality, with no stoppers of thought or restrains on logic.” (Imprint: Novinka).