The New York Times, March 1, 2019

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One night in November 1999, a 26-year-old woman was raped in a parking lot in Grand Rapids, Mich. Police officers managed to get the perpetrator’s DNA from a semen sample, but it matched no one in their databases.

Detectives found no fingerprints at the scene and located no witnesses. The woman, who had been attacked from behind, could not offer a description. It looked like the rapist would never be found.

Five years later, there was a break in the case. A man serving time for another sexual offense submitted a DNA sample with his parole application. The sample matched DNA from the rape scene.

There was just one catch: The parolee had an identical twin, and standard DNA tests can’t distinguish between identical twins. Prosecutors had no additional evidence to rule out one or the other. Because they couldn’t press charges against either of the men, the case remains open nearly 20 years later.

Continue reading “One Twin Committed the Crime — but Which One? A New DNA Test Can Finger the Culprit”

The New York Times, February 28, 2019

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High in the mountains of Central America lives a little known creature called Alston’s singing mouse. This rodent, which spends its life scuttling around the floor of the cloud forest, may not seem like it has much to tell us about ourselves.

But the mouse produces remarkable songs, and researchers have discovered some profound similarities to our own conversations. This ability may be linked evolutionarily to the ancient roots of human language.

Continue reading “These Mice Sing to One Another — Politely”

The New York Times, February 21, 2019

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In 1985, the chemist Steven A. Benner sat down with some colleagues and a notebook and sketched out a way to expand the alphabet of DNA. He has been trying to make those sketches real ever since.

On Thursday, Dr. Benner and a team of scientists reported success: in a paper, published in Science, they said they have in effect doubled the genetic alphabet.

Continue reading “DNA Gets a New — and Bigger — Genetic Alphabet”

The New York Times, January 30, 2019

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Over the past decade, the Denisova Cave in Siberia has yielded some of the most fascinating fossils ever found. To the naked eye, they are not much to look at — a few teeth, bits of bone.

But the fossils contain DNA dating back tens of thousands of years. That genetic material shows that Denisovans were a distinct branch of human evolution, a lost lineage.

Continue reading “High Ceilings and a Lovely View: Denisova Cave Was Home to a Lost Branch of Humanity”

The New York Times, January 28, 2019

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In 2014 John Cryan, a professor at University College Cork in Ireland, attended a meeting in California about Alzheimer’s disease. He wasn’t an expert on dementia. Instead, he studied the microbiome, the trillions of microbes inside the healthy human body.

Dr. Cryan and other scientists were beginning to find hints that these microbes could influence the brain and behavior. Perhaps, he told the scientific gathering, the microbiome has a role in the development of Alzheimer’s disease.

The idea was not well received. “I’ve never given a talk to so many people who didn’t believe what I was saying,” Dr. Cryan recalled.

Continue reading “Germs in Your Gut Are Talking to Your Brain. Scientists Want to Know What They’re Saying.”