December 18, 2024: On-Earth analogs of Mars, the human brain is disappointingly slow, and baby whales whine for food, too. —Andrea Gawrylewski, Chief Newsletter Editor | | | A newborn humpback whale calf resting on its mother's back. Cétamada Association | | | • Listen to the noises, which sound like burps, barks and snorts, that baby baleen whales make to beg for food. | 3 min read | | | agefotostock/Alamy Stock Photo | | | Spain's salty Tirez Lagoon dried up over the course of 20 years, becoming completely barren by 2015. So barren that it resembles the surface of Mars. A team of astrobiologists (biologists who look for life in space) analyzed microbes in Tirez soil samples from 2002 and 2021 and found that microbes called prokaryotes that were adapted to survive in wet conditions in 2002 could thrive in extremely dry ones by 2021.
Why this matters: Learning how lifeforms adapt (or don't) to changing landscapes on this planet may give us an idea of how to search for signs of life on the Red Planet. The researchers measured the 2021 samples for fatty acids called lipids, which form in cell membranes. They confirmed that these long-lasting molecules would be a good target in searching for signs of previous life on other planets.
What the experts say: Such time analogs of how organisms adapt raise "an interesting idea—that not only should we explore more for understanding Mars but also our own planet," says Nathalie Cabrol, chief scientist at the SETI Institute, which focuses on the search for extraterrestrial intelligence. There is a "dire need" for research on how fast Earth's biospheres are morphing because of climate change, she says. | | | It may feel like you have a million thoughts at once, but it turns out that human beings think at a fixed, excruciatingly slow speed. Researchers pooled data from studies across different fields (like neuroscience and psychology) that all looked at a range of elements, from the processing speed of single neurons to the cognitive abilities of memory champions. They ran their own calculations and determined that human thought occurs at a rate of about 10 bits per second—each thought happening one-at-a-time.
Why this is interesting: In contrast to their tortoise-paced thinking, human sensory systems gather data at about one billion (!) bits per second. Why such a discrepancy between sensing and thinking? The authors say the answer might have something to do with the brain's need to frequently switch tasks and integrate information across different neural circuits. All in all, they estimate that the total amount of information a person can learn across their lifetime could comfortably fit on a small thumb drive.
What the experts say: "Nature, it seems, has built a speed limit into our conscious thoughts, and no amount of neural engineering may be able to bypass it," says Tony Zador, a neuroscientist at Cold Spring Harbor Laboratory. "Why? We really don't know, but it's likely the result of our evolutionary history." | | | • One in four people will be affected by a mental health issue or a psychological disorder at some point in their lives, with anxiety and depression being the most common. A new field of study called neuroaesthetics is demonstrating how art and other aesthetic pursuits can change the human brain and behavior, writes Susan Magsamen, the founder and executive director of the International Arts + Mind Lab (IAM Lab), Center for Applied Neuroaesthetics, at Johns Hopkins University School of Medicine. Working on an art project for just 45 minutes, regardless of your skill, can decrease stress and has been shown to reduce cortisol levels in up to 75 percent of people, she says. | 4 min read | | | • How about some good news? The invasive murder hornet has been eradicated from the U.S. | The New York Times | • Sampling sheep earwax can tell farmers if their herds are eating poisonous grasses. | ScienceNews | | | • Leaked internal documents show that UnitedHealthcare is strategically limiting treatments for children with autism. | ProPublica | | | Revisiting the editors' favorite science stories of 2024. | | | Tukpahlearik Creek in northwestern Alaska's Brooks Range runs bright orange where permafrost is thawing. Taylor Roades | | | • In the last few years, scientists have recorded rivers and streams in pristine regions of Alaska that are as acidic as vinegar and have levels of electrical conductivity (an indicator of dissolved metals or minerals) similar to that of industrial wastewater. Plus, the waterways are turning orange. Scientists agree that climate change is behind the changes, but they aren't yet sure precisely how. One possible explanation is that thawing permafrost allows bacteria to reduce iron, which is soluble in water. Once in the water, that reduced iron can be oxidized, turning bright orange. | 21 min read | | | Just yesterday I was waxing philosophical that what is unknown by humans is vast compared with what we do know. And today we report that scientists estimate that all the knowledge one human can accumulate in a lifetime could fit on a modest thumb drive. If that doesn't humble you, I don't know what will! All the more reason to pool our collective knowledge and let in as much information as we can. | Thank you for filling your proverbial thumb drive with me every day. Send any comments, ideas or suggestions to: newsletters@sciam.com. Until tomorrow! | —Andrea Gawrylewski, Chief Newsletter Editor | | Subscribe to this and all of our newsletters . | | | | Scientific American
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