At the heart of all life is a code. Our cells use it to turn the information in our DNA into proteins. So do maple trees. So do hammerhead sharks. So do shiitake mushrooms. Except for some minor variations, the genetic code is universal.

It’s also redundant. DNA can code for the same building block of proteins in more than one way. Researchers have long debated what purpose this redundancy serves — or whether it’s just an accident of history.

Continue reading “Scientists Are Learning to Rewrite the Code of Life” →

In April, a team of scientists based at the University of Cambridge claimed that a planet orbiting a distant star bore a possible signature of life. The announcement kicked up a fierce debate among astronomers, with many skeptics arguing that the evidence was too ambiguous.

Now a NASA-led team has made a new set of observations of the planet known as K2-18b, which lies 124 light-years from Earth. They have provided a clearer picture of the planet — confirming the presence of water, perhaps even as a liquid ocean.

Continue reading “Hints of Life on Exoplanet Recede Even Further” →

German paleontologists have discovered a 247-million-year-old fossil of a reptile with a bizarre row of plumes sprouting from its back. The elaborate display is a paradox of evolution. The plumes bear some similarities to feathers, even though the newly discovered reptile was not closely related to birds.

Stephan Spiekman, a paleontologist at the Stuttgart State Museum of Natural History in Germany and an author of the new study, said that the discovery could change how scientists think about the origin of feathers. In birds, a complex network of genes is enlisted to sprout feathers from their skin. Part of the network might have already evolved in early reptiles more than 300 million years ago.

Continue reading “Something Like Feathers Grew on a 247-Million-Year-Old Reptile” →

To prepare for future pandemics, scientists look to the past for clues. Over the last century, a series of new pathogens have swept the world, including H.I.V., Zika virus and SARS-CoV-2.

But the further back researchers look, the fuzzier that history becomes. Thucydides chronicled the plague of Athens, a disease that ravaged the city-state around 430 B.C. Despite all his gory details — “the inward parts, such as the throat or tongue, becoming bloody and emitting an unnatural and fetid breath” — today’s historians and scientists still don’t know which pathogen was responsible for it.

Continue reading “A 37,000-Year Chronicle of What Once Ailed Us” →

Companies like OpenAI and Meta are in a race to make something they like to call artificial general intelligence. But for all the money being spent on it, A.G.I. has no settled definition. It’s more of an aspiration to create something indistinguishable from the human mind.

Artificial intelligence today is already doing a lot of things that were once limited to human minds — such as playing championship chess and figuring out the structure of proteins. ChatGPT and other chatbots are crafting language so humanlike that people are falling in love with them.

Continue reading “Scientists Use A.I. to Mimic the Mind, Warts and All” →