Rain may have been an essential ingredient for the origin of life, according to a study published on Wednesday.

Life today exists as cells, which are sacs packed with DNA, RNA, proteins and other molecules. But when life arose roughly four billion years ago, cells were far simpler. Some scientists have investigated how so-called protocells first came about by trying to recreate them in labs.

Many researchers suspect that protocells contained only RNA, a single-stranded version of DNA. Both RNA and DNA store genetic information in their long sequences of molecular “letters.”

Continue reading “How Did the First Cells Arise? With a Little Rain, Study Finds.” →

When people suffer severe brain damage — as a result of car crashes, for example, or falls or aneurysms — they may slip into a coma for weeks, their eyes closed, their bodies unresponsive.

Some recover, but others enter a mysterious state: eyes open, yet without clear signs of consciousness. Hundreds of thousands of such patients in the United States alone are diagnosed in a vegetative state or as minimally conscious. They may survive for decades without regaining a connection to the outside world.

Continue reading “Unresponsive Brain-Damaged Patients May Have Some Awareness” →

Scientists have developed a new weapon against H.I.V.: a molecular mimic that invades a cell and steals essential proteins from the virus.

A study published in Science on Thursday reported that this viral thief prevented H.I.V. from multiplying inside of monkeys.

The new therapeutic approach will soon be tested in people, the scientists said. Four or five volunteers with H.I.V. will receive a single injection of the engineered virus. “This is imminent,” said Leor Weinberger, a virologist at the University of California, San Francisco, who led the new study.

Continue reading “Engineered Virus Steals Proteins From H.I.V., Pointing to New Therapy” →

A new study describes 700,000-year-old teeth and arm bones from one of our most enigmatic relatives: a toddler-size “hobbit” who lived on a small island between the Indian and Pacific Oceans.

The study, published on Tuesday in the journal Nature Communications, suggests that the species, Homo floresiensis, sometimes nicknamed hobbits, could be even smaller than previously thought. But the results still left scientists divided over how such exceptional humans evolved.

Continue reading “Scientists Find Arm Bone of Ancient ‘Hobbit’ Human” →

There is no rose without thorns, the old saying goes. But to botanists, there is no rose with thorns: The spiky outgrowths of a rose stem are called “prickles,” and are biologically distinct from the stiff, woody thorns of other plants.

Prickles are a remarkable example of evolution repeating itself. In the past 400 million years, plants evolved them 28 different times. Roses grow prickles on their stems, whereas others grow them on their leaves or their fruits. Grasses grow tiny prickles on their flowering tufts. Solanum atropurpureum, a wild relative of potatoes that grows in Brazil, has prickles so nasty that they’ve earned it two fearsome nicknames: “Purple devil” and “Malevolence.”

Continue reading “How Did Roses Get Their Thorns?” →