Today in Science: Yes, humans are still evolving

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May 23, 2025—Surprising results from genetic studies show humans are still evolving. Plus, the hurricane season forecast just came out, and contact lenses that let you see infrared light.    —Andrea Gawrylewski, Chief Newsletter Editor TODAY'S NEWS A satellite view of Hurricane Milton on October 9, 2024. CIRA/NOAA NOAA says it's ready for the active hurricane season predicted this year. But scientists across the country are sounding the alarm about personnel shortages and budget cuts. | 5 min read New contact lenses use nanoparticles to give people infrared vision—even with their eyes shut. | 3 min read The White House's $175-billion plan to protect the U.S. from nuclear annihilation will probably cost much more—and deliver far less—than has been claimed, says nuclear arms expert Jeffrey Lewis. | 10 min read This is what the FDA's plans to reduce access to COVID vaccinations means for your health. | 7 min read Could we talk (squeak?) to dolphins? A large language model might make it possible. | 19 min listen "Micromorts" and "microlives" are the statistical units that help mathematicians calculate the risk of dying from anything. | 5 min read More News TOP STORIES The Uru people of the Bolivian Altiplano have a gene variant that helps them metabolize the toxic arsenic found in their drinking water. Gaston Zilberman Still Evolving After All These Years  Recent studies of modern and ancient human genomes suggest that Homo sapiens have experienced many major episodes of natural selection (evolutionary pressure) in the past few thousand years. As our ancestors spread out around the globe tens of thousands of years ago they encountered new environments, each with its own foods, diseases and toxic substances. Examples of human evolution: Starting around 10,000 years ago when people first settled in regions of the Andes mountains, gene variants arose that code for enzymes to break down arsenic in the liver (it leaches into groundwater in some regions there). Around 4,500 years ago a gene spread in Europe and South Asia enabling people to digest milk past childhood. Around 8,500 years ago early farmers spread an allele (a version of a gene) that helped them synthesize long-chain polyunsaturated fatty acids from plant-based foods—these fatty acids are crucial for forming cell membranes, especially in the brain, and normally would only be obtained by eating meat.  Why this matters: Such shifts in our ancestral DNA were among dozens in humans, based on new genetic analyses. For much of the 21st century, evolutionary biologists have assumed that humans evolved at a leisurely pace in recent millennia. But genetic studies suggest that H. sapiens experienced many major episodes of natural selection.   What the experts say:  "It shows the plasticity of the human genome," says Karin Broberg of the Karolinska Institute in Sweden, who studies the genetics of susceptibility to environmental toxic substances. "We've spread throughout the world, and we live in very extreme environments, and we're able to make them our homes. We are like rats or cockroaches—extremely adaptable."

PLAY NOW Quiz time! Test your science knowledge with this week's quiz. Also check out today's Spellements puzzle. This week, reader James R. spotted that the word cevian was missing from Spellements this week. A cevian is a line segment that joins a vertex of a triangle with a point on the opposite side. Extra points for geometry words, James! More Games EXPERT PERSPECTIVES When a hurricane or tornado starts to form, local weather forecasters quickly pull up maps that track the storm's movement and show where it's headed. Behind the scenes, a vast network of satellites, airplanes, radar, computer models and weather analysts are providing access to the latest data—and warnings when necessary. This data comes from the National Oceanic and Atmospheric Administration. "Some private companies are starting to invest in satellites, but it would take an enormous amount of money to replicate the range of instrumentation and coverage that NOAA has in place," write Christine Wiedinmyer and Kari Bowen, scientists at CIRES, an institute for environmental study at the University of Colorado Boulder. "The government agency can be held accountable in a way private businesses are not because it answers to Congress. So, the data is trustworthy, accessible and developed with the goal to protect public safety and property for everyone. Could the same be said if only for-profit companies were producing that data?" they ask. | 5 min read More Opinion MOST POPULAR STORIES OF THE WEEK Vitamin D May Slow Cells' Aging | 4 min read Mitochondria Are More Than Powerhouses—They're the Motherboard of the Cell | 18 min read Astronomers' Epic Quest to Witness the Cosmic Dawn | 12 min read My colleague, senior sustainability editor Andrea Thompson, alerted me this morning that this year's first hurricane will be named "Andrea." Ours has never been used to name a hurricane before (though it was a few times for tropical storms). A wish on behalf of all human Andreas (if I may) on the inevitable materialization of our meteorological namesake: Blow out to sea, and leave us be! Best wishes for a calm hurricane season and restful long weekend. Send any thoughts or feedback to: newsletters@sciam.com. See you Monday.   —Andrea Gawrylewski, Chief Newsletter Editor

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