Scientists may never know what sparked life on our planet ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏ ͏
September 21, 2026—Will scientists ever know, for sure, how life began on Earth? Plus, dogs have a rich inner world, and most scientists are using AI for their research. Monday, let's go!
—Andrea Gawrylewski,
Chief Newsletter Editor
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Origins of Life
We’re back this week with more impossible questions in science. Today, how did life begin on Earth? A scientific field called Origins of Life, or OoL, is devoted to finding the answer. Several hypotheses are in the running, but the details are far from agreed upon. This may be a question for which scientists are able to find only plausible explanations.
What scientists agree on: Earth’s oldest fossils date back to at least 3.4 billion years ago, with evidence that life may have arisen more than half a billion years before that. Scientists also generally agree that life didn’t come into being in a single flash but in an extended sequence of events, (i.e. chemical reactions lead eventually to metabolism or the storage and transmission of genetic information which led to cells with boundaries). But the order of events is not agreed upon.
RNA First: Some scientists believe RNA was the initial important part of biology to form. Before DNA or proteins or cells, RNA stored information and catalyzed chemical reactions. RNA would have assembled into single strands that could make copies of themselves, setting up a process of reproduction and evolution.
Metabolism First: Supporters of this idea say the critical first development was the ability to convert basic chemicals into more complex compounds. Some simple chemical reactions happened to produce energy-storing molecules. Those molecules started more chemical reactions, which became increasingly complex as the cycle continued. Eventually the self-sustaining chemical reactions resulted in structures resembling RNA.
Other possibilities: One idea that is waning in popularity is the guess that space rocks may have seeded life on this planet. Samples of asteroids and meteorites suggest they don’t have the kind of organic molecules whose structure matches what life uses here. Experts have also considered that the regions around deep-sea hydrothermal vents may have spurred life. But that idea, too, is fading away: surrounded by the entire ocean, famously large, vents could not have concentrated chemical constituents enough, scientists say.
Join the discussion: Which Origins of Life theory do you like best? Do you think we’ll ever solve this question? Share your thoughts here.
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Ekaterina savyolova via Getty Images
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A Dog's Life
More and more research is asking what dogs really think—not just how their owners see them. And studies show that our fuzzy friends have a much more complex inner world than we thought. One community science experiment involving 10,000 participants found that when dogs were given buttons that “spoke” words, the overwhelming majority used the buttons in a non-random way, communicating things like “want food” and “go outside”; another recent study found that dogs blink in response to other dogs and humans blinking; and MRI scans of dogs have shown that they have specific reactions when viewing pictures of different human emotions.
Why this is interesting: Past research has shown that dogs can distinguish between words, male and female voices, other barks and even different languages. And that cute head tilt dogs do when you’re talking to them? It’s another sign they’re processing human language. Though pet owners may not be surprised at the emotional intelligence of our best friends, this field is relatively new, and scientists are just beginning to use tools like MRIs and other brain monitoring technology in their natural environment.
What the experts say: To better understand, care for and coexist with our fuzzy friends, we must continue asking what dogs know and understand about themselves and the world around them, including the elusive mystery of how dogs process time, says Federico Rossano, a cognitive researcher at the University of California, San Diego. “Dogs have been our companions for 15,000 years,” he says. “Half the population has dogs in their homes. Don’t you want to know what your roommate thinks?” —Mary Randolph, News Intern
Join the conversation: What is the most incredible, smart, intuitive, emotional, sweet, impressive thing your dog as ever done? Share your thoughts here.
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SCIENTIFIC AMERICAN EVENT
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Tomorrow at the Brooklyn Book Festival, Scientific American will be hosting a panel exploring science in fiction, featuring four of this year's highly anticipated book releases. The panel will include authors Heather Frances, Isabel J. Kim, Matthew Kressel and Sarah G. Pierce, and be moderated by SciAm's Brianne Kane.
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Amanda Montañez; Source: “AI in Science: Early Insights,” by Mihai Codreanu et al. Released online September 2026 (data)
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A report out this week from Google, Google DeepMind and the Massachusetts Institute of Technology’s MIT FutureTech set out to measure how AI is changing the economics of science in a variety of fields. The study combines a survey of 637 scientists with analyses of 15 million Gemini conversations and an inventory of more than 2,600 specialized models. (The scientists were recruited through specialist panels, so frequent AI users may have been overrepresented.) The majority of scientists are using the technology a lot, but so far AI hasn't helped advance laboratory studies. Read more here.
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Mexico City flushes its waste into a rural valley. Cases of cancer in the people who live near the site are surging. | The New York Times ($)
Addiction clinics are seeing a rise in kratom and 7-OH withdrawal cases. | STAT ($)
Scientists in Montana find an incredibly well-preserved feather from 66 million years ago. | Current Biology
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Tiny investment, enormous universe: subscribe to Scientific American for 90 days for just $1 and help keep this newsletter going.
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The work of origin-of-life researchers, some who recreate early Earth conditions in sealed-up laboratory tanks, reminds me of the work of Jenny Bergner. I wrote about the up-and-coming U.C. Berkeley astrochemist earlier this year. In her lab, Bergner and colleagues try to recreate the harsh conditions of interstellar space—just above absolute zero and a near-perfect vacuum—and see what molecules can arise. She told me that a similar set of organic molecules can spontaneously form in space that scientists have observed in labs here on Earth. The same fundamental reactions are occurring, but the physical environment of interstellar space is more restrictive. Something about Earth has the magic recipe for life, and I can understand the drive to figure out what it is.
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Welcome to a new week of discovery! Reach out any time with comments or questions: newsletters@sciam.com. See you tomorrow!
—Andrea Gawrylewski,
Chief Newsletter Editor
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