Today in Science: Did our ancestors eat each other?

Science meets inbox June 28, 2023: Ancient hominins may have eaten each other, a heatwave that just won't quit and how to know if aliens are eavesdropping on us. Read below! —Andrea Gawrylewski, Chief Newsletter Editor TOP STORIES Flesh Eaters A paleoanthropologist examining fossils at the National Museums of Kenya in Nairobi found intriguing marks on an ancient hominin tibia bone from approximately 1.45 million years ago. The scrapes on the bone were consistent with marks left by early stone butchering tools. "The most logical conclusion is, like the other animals, this hominin was butchered to be eaten," says Briana Pobiner, a palaeoanthropologist at the Smithsonian Institution, who did the subsequent study on the fossil. Why this is intriguing: The exact species that the tibia belongs to (Homo erectus? H. habilis? Paranthropus boisei?) is unknown. Even so, the fossil could be the earliest evidence that ancient humans butchered and ate each other's flesh. What the experts say: "It suggests that hominins using stone tools to butcher and consume other hominins happened as a typical part of life for our ancestors," says Jessica Thompson, a palaeoanthropologist at Yale University. Small gashes are visible on this tibia bone from an unidentified species. Credit: Jennifer Clark Big Texas Heat Last week I wrote about the stifling heat wave that has been baking most of Mexico for weeks. The meteorological phenomenon causing that extreme weather is also roasting large portions of Texas and the Southeast. A major "heat dome" has parked itself over the region and will keep temperatures soaring to deadly highs for at least another week.  How it works: A high-pressure system—also called a ridge—is stuck over Texas and Mexico. It causes air to sink and compress, becoming warmer. These systems also bring clear skies, letting through plenty of sunlight that further bakes the surface. The humidity of southern Texas in particular can launch the heat index even higher–125 degrees F in Corpus Christi on June 19 (cue melting face emoji). It takes a big push from the jet stream or another strong weather system to boot out the dome, but so far nothing has developed. What the experts say: Extreme heat is deadlier than hurricanes, tornadoes, and floods COMBINED. The very young and the elderly are particularly at risk. Stay indoors as much as possible and drink more water than you usually do. "If you're feeling thirsty, it's already too late," says Andrew Quigley, a meteorologist at the NWS office for Austin and San Antonio. More:  1. Why Extreme Heat is So Deadly 2. This Hot Summer Is One of the Coolest of the Rest of Our Lives Children play and cool off at a splash park in downtown Houston, Tex., on June 15, 2023. Credit: Chen Chen/Xinhua/Alamy Stock Photo TODAY'S NEWS • A 25-year-old bet about consciousness between neuroscientist Christof Koch and philosopher David Chalmers has finally been settled. | 7 min read • Wildfire smoke from Canada is causing poor air quality again. Here's what those air quality alerts mean. And here's how wildfire smoke reacts with city air to create toxic ozone. | Both a 4 min read • Seville, Spain, named its first heat wave last year Zoe. Now the country has named its second: "Yago" becomes Spain's second named heat wave.| 3 min read More News EXPERT PERSPECTIVES • Could aliens in the galaxy eavesdrop on our cell phone conversations? If the alien tech is the same as ours, we are safe, says Phil Plait, astronomer and science writer. But if they're more technologically advanced than us, they may have far more sensitive detection methods and are perhaps capable of picking up mobile transmissions even from interstellar distances, he writes.  | 6 min read WHAT WE'RE READING • An Iraqi Historian was murdered after being labeled a spy on Facebook. Meta did not act to silence online threats against him. | Business Insider • Some states are charging those who share drugs that lead to overdoses with first degree murder. Some find this approach misplaced and extreme. | The New York Times • The private space industry caters to the same group of people as those lost in the imploded underwater submersible Titan last week. Is it prepared to endure similar public failures? | Space News More Opinion I know all the heatwave news can be discouraging. The American Psychiatric Association officially recognizes climate change and its effects as a growing threat to mental health (therapists are calling it "eco-anxiety"). Mindfulness tactics (concentrating on your breath moving in and out of your lungs, for example) can help ease a spinning mind. If you're curious about the science backing this up check out our recent feature on mindfulness. Take care of yourself and reach out any time to chat with me about how you're liking this newsletter: newsletters@sciam.com. See you tomorrow! —Andrea Gawrylewski, Chief Newsletter Editor Subscribe to this and all of our newsletters here. Scientific American One New York Plaza, New York, NY, 10004   Support our mission, subscribe to Scientific American here   Unsubscribe Email Preferences