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"Neandertal DNA may affect how we think."

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Russ Roberts (https://hawaiisciencejournal.blogspot.com).

 

January 21, 2025: Inherited Neandertal DNA may affect human cognition, the fascinating history of Venn diagrams, and the contagious trickle of pee. —Andrea Gawrylewski, Chief Newsletter Editor TODAY'S NEWS Chimpanzee (Pan troglodytes) urinating in tree, Nyungwe National Park, Rwanda, Africa. Eric Baccega/Nature Picture Library/Alamy Stock Photo • Just as people often yawn when they see someone else do it, for chimpanzees, peeing is contagious. | 3 min read • An international group of scientists proposes that the measurement of adiposity--that is, excess body fat--replace the BMI scale when assessing health. | 4 min read • The upper stage of SpaceX's Starship vehicle exploded 8.5 minutes after liftoff last week. The cause was likely an oxygen or fuel leak, Elon Musk said. | 2 min read • Climate change absolutely fueled the California wildfires. Here's how. | 4 min read More News Are you enjoying this newsletter? If you want to dive deeper into the articles I link to, consider a subscription to Scientific American. We have special discounts for Today in Science readers!  TOP STORIES Neandertals had a braincase that was long and low in shape (left), in contrast to the globular braincase of Homo sapiens (right). People today with higher percentages of Neandertal DNA are more likely to have an elongate skull reminiscent of Neandertals. Philipp Gunz/MPI EVA Leipzig Neandertal Brain People outside of Africa can trace 1 to 2 percent of their genome to Neandertal ancestors–relatives of modern humans who went extinct some 30,000 years ago. People with more Neandertal DNA are more susceptible to immune disorders and have an increased risk for severe COVID. Neandertal DNA may affect skin or hair color, how readily our blood clots or determine how prone we are to certain skin cancers, thiamine (vitamin B1) deficiency, obesity and diabetes. Researchers have found that autistic people tend to have more rare Neandertal DNA single nucleotide polymorphisms (where one amino acid in the code is replaced by another). How this happened: Between 50,000 and 40,000 years ago, the Neandertal population dwindled to perhaps as few as 5,000 individuals. Because of this shallowing of the gene pool, the Neandertal genome contains many potentially harmful mutations. Our species probably inherited some of them when our ancestors interbred with Neandertals tens of millennia ago. What the experts say: “The notion that Neandertal DNA might significantly influence our brains and behavior, however, is actually a bit counterintuitive,” given that they went extinct, write Emily L. Casanova and F. Alex Feltus, professors of neuroscience and genetics, respectively. “Yet studies published over the past decade have shown that some Neandertal DNA has in fact persisted in and around some brain-related genes in modern humans.” EXPERT PERSPECTIVES •  A U.S. withdrawal from the World Health Organization (WHO) could be devastating, write Lawrence O. Gostin, a professor at Georgetown University and director of the World Health Organization Collaborating Center for National and Global Health Law, and Eric A. Friedman, a scholar at the Georgetown University Law Center. The U.S. is the WHO’s largest member-state funder, representing 22 percent of all WHO-assessed dues. With restricted or eliminated U.S. funding, "the organization’s programming would be hollowed out, and its pandemic responses capacities would be diminished, endangering health everywhere," they say. "Since the creation of WHO, the world has embraced international cooperation in health. Throughout those decades, the U.S. was the unrivaled global health leader, recognizing that we all inhabit a single planet and face common health threats." | 5 min read More Opinion INFOGRAPHIC OF THE DAY Amanda Montañez; Source: “Venn Diagrams and Independent Families of Sets,” by Branko Grünbaum in Mathematics Magazine, Vol. 48, No. 1; January 1975 (reference) Mathematician John Venn debuted his namesake diagrams in 1880 as a way to visualize contemporary advances in logic. The overlapping circles represent sets of certain elements (for example, things that are cuddly or Broadway shows). The overlapping region between two circles contains elements that belong to both sets (e.g., “cats”). Venn diagrams that contain three sets work fine, but adding more circles doesn’t work, since the number of new overlapping regions outnumbers the points of intersection of the circles. Venn diagrams using spheres or ellipses solve this problem….for a time. Venn and his successors believed that ellipses couldn’t portray all 32 regions required for a five-set diagram. Not until 1975 did mathematician Branko Grünbaum prove them wrong by example. It's not just genes, the latest research keeps demonstrating that Neandertals were not so different from us. They created complex tools, used plants as medicine, and even made jewelry and art. Despite their cognitive evolution, the Neandertals ultimately went extinct (and their genetic legacy lives on in our DNA). We humans have survived this long, yes. But we've also flirted with extinction before. And I do not think it's safe to say we will never come close again. Thriving on this planet is not a guarantee for any lifeform, including us. Welcome to a new week of scientific discovery! Let me know how I'm doing by emailing: newsletters@sciam.com. See you tomorrow. —Andrea Gawrylewski, Chief Newsletter Editor Subscribe to this and all of our newsletters here.

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