SPONSORED BY  | | | | January 10, 2024: Why the "Anthropocene" matters to all of us, supergenes that rarely change and the colors of Uranus and Neptune revealed. —Andrea Gawrylewski, Chief Newsletter Editor | | | Have you heard of the Anthropocene? For the last 20 years or so, scientists have debated whether human's effects on Earth constitute a new geologic "age," which they dubbed the Anthropocene (anthro, from the Greek for "human"). Could our transformations of the planet's atmosphere, land and soil, and its lifeforms be measured in millennia to come, as were the geologic shifts that accompanied previous eras like the Holocene and Pleistocene?
Marks on Earth: Greenhouse gases have risen dramatically since the industrial revolution began, more than 250 years ago. Along with them, black carbon–an airborne byproduct of fossil fuel combustion–blankets rocks and ice. Modern polymers (plastics) can be detected in sediment layers, as can radioactive isotopes from nuclear testing during the 1940s. An accounting of devastated populations of land and marine animals and plants will be left in the fossil record.
What the experts say: Some people (especially wealthy humans) seem to think that we and other life-forms will just be able to "adapt" to these dramatic changes, writes Naomi Oreskes, science historian at Harvard University. "The Anthropocene reminds us that the challenge we face is geological in scale. It affects the whole Earth. It reminds us that as this new epoch unfolds, there won't be anywhere to hide." | | | What's the purpose of sex? A classical geneticist would tell you that sex allows genes on chromosomes from two individuals to recombine and shuffle around to yield the most diverse traits possible (which makes offspring more adaptable to whatever their environment may throw at them). But scientists have discovered that in some species, certain genes are rarely shuffled. They're called "supergenes" and have so far been discovered in ants, butterflies, birds, fish, plants and fungi.
Why this is so cool: Suppressed recombination (minimal gene shuffling between chromosomes) happens on the sex chromosomes–some traits are more advantageous to males or females, and so are clustered on the sex chromosomes where they're preserved. But supergenes can regulate other traits not on sex chromosomes, like social behaviors. Researchers recently found a supergene in Formica wood ants that determines whether they will have single or multiple queens in their colony.
What the experts say: "We know that there are parts of chromosomes where there's a lot of recombination and parts where there's less," says Jessica Purcell, who studies ants at UC Riverside. "And the degree of linkage between genes in those regions can have really important implications for the evolutionary trajectory of whatever traits are under their control." | | | • The private U.S. Peregrine lander was meant to be the first commercial spacecraft to operate on the surface of the moon. Now it might not reach lunar orbit at all because of an anomaly in its propulsion system. | 5 min read | | | • Attendees of the recent COP28 meeting pledged to ramp up renewable energy programs and fund climate reparations. But the meeting failed to pin down any strict timeline of steps to achieve the goal of the Paris Agreement--limiting global warming to 1.5 to 2 degrees C, write scientists Christopher Wolf and William J. Ripple. "Any genuine strategy to address global warming must ultimately go beyond words and voting—it should include a thorough execution plan with defined goals, explicit measures and mechanisms to ensure accountability for outcomes," they say. | 5 min read | | | SPONSORED CONTENT BY NOVAVAX | Novavax is a global leader in vaccine development and research | The company's vaccine technology is built on a protein-based platform and combines the power of a well-understood approach with an innovative nanoparticle technology. It is intended to help protect against some of the world's most pressing viral diseases. Learn More. | | | • Should doctors let patients die from anorexia? This striking piece explores the question. | The New York Times | | | • For decades, all websites on the Internet have been designed with Google in mind. And now everything looks the same. | The Verge | | | • Journalist Tom Scocca details the mysterious medical condition that took over--and upended--his life. | New York Magazine | | | Credit: NASA/JPL-Caltech (Uranus and Neptune); "Modelling the Seasonal Cycle of Uranus's Colour and Magnitude, and Comparison with Neptune," by Patrick G. J. Irwin et al., in Monthly Notices of the Royal Astronomical Society, Vol. 527, No. 4; February 2024 (reprocessed images) | | | A fresh analysis of Voyager 2 images shows both ice giants Uranus and Neptune are in fact a similar shade of greenish blue, which is the "most accurate representation yet" of the planets' colors. The color comes from a layer of methane in the planets' atmospheres, which absorbs red color from the sun's light. | 3 min read | | | When I feel overwhelmed thinking about how drastically humans are changing Earth, I plug in my headphones, take a deep breath and listen to an episode of National Parks Nature Walks, a podcast series we published in 2021. Most of each episode is spent simply listening to sounds of nature, and it's a soothing reminder that plenty of life on this planet is carrying on more-or-less like usual. I can't recommend this podcast enough. | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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