In 1961, two biologists named Leonard Hayflick and Paul Moorehead discovered that old age is built into our cells. At the time, many scientists believed that if healthy human cells were put in a flask with a steady supply of nutrients, they would multiply forever. But when Dr. Hayflick and Dr. Moorehead reared fetal human cells, that’s not what they found. Time and again, their cells would divide about 50 times and then simply stop.

Cells that stop growing this way came to be known as senescent.

Continue reading “Signs of Aging, Even in the Embryo” →

Where did dogs come from? That simple question is the subject of a scientific debate right now. In May, a team of scientists published a study pointing to East Asia as the place where dogs evolved from wolves. Now, another group of researchers has announced that dogs evolved several thousand miles to the west, in Europe.

This controversy is intriguing even if you’re not a dog lover. It illuminates the challenges scientists face as they excavate the history of any species from its DNA.

Continue reading “Wolf to Dog: Scientists Agree on How, but Not Where” →

The laboratory of Vera Gorbunova and Andrei Seluanov, a husband-and-wife team of biologists at the University of Rochester, has the feel of a petting zoo. They maintain colonies of several species of rodents — some familiar, like mice and guinea pigs, and some much more exotic, like blind mole rats from Israel and naked mole rats from East Africa.

Amusing children with furry creatures is not their goal, however. The biology of animals is mysteriously diverse, and lurking within it may be clues to new kinds of medicine.

Continue reading “A Homely Rodent May Hold Cancer-Fighting Clues” →

The stories of scientists create new scientists. Alexander von Humboldt — the most famous naturalist of the early 19th century — chronicled his epic expeditions, between 1799 and 1804, in his “Personal Narrative of a Journey to the Equinoctial Regions of the New Continent.” When a nature-loving student at Cambridge named Charles Darwin read the book, it changed his life. He read passages aloud to his professors and learned Spanish so that he could follow in Humboldt’s footsteps.

Continue reading “Apes” →