Nearly 11,000 years ago, a man died in what is now Nevada. Wrapped in a rabbit-skin blanket and reed mats, he was buried in a place called Spirit Cave.

Now scientists have recovered and analyzed his DNA, along with that of 70 other ancient people whose remains were discovered throughout the Americas. The findings lend astonishing detail to a story once lost to prehistory: how and when humans spread across the Western Hemisphere.

The earliest known arrivals from Asia were already splitting into recognizably distinct groups, the research suggests. Some of these populations thrived, becoming the ancestors of indigenous peoples throughout the hemisphere.

Continue reading “Crossing From Asia, the First Americans Rushed Into the Unknown” →

On the wall of a cave deep in the jungles of Borneo, there is an image of a thick-bodied, spindly-legged animal, drawn in reddish ocher.

It may be a crude image. But it also is more than 40,000 years old, scientists reported on Wednesday, making this the oldest figurative art in the world.

Until now, the oldest known human-made figures were ivory sculptures found in Germany. Scientists have estimated that those figurines — of horses, birds and people — were at most 40,000 years old.

Continue reading “In Cave in Borneo Jungle, Scientists Find Oldest Figurative Painting in the World” →

People have always told stories about their ancestral origins. But now millions of people are looking at their DNA to see if those stories hold up. While genetic tests can indeed reveal some secrets about our family past, we can also jump to the wrong conclusions from their results.

The reception of Senator Elizabeth Warren’s DNA results is a textbook case in this confusion.

On Monday morning, Senator Warren released an analysis on her DNA showing that six to 10 generations back she had a Native American ancestor.

Continue reading “Before Arguing About DNA Tests, Learn the Science Behind Them” →

Cancer is a disease of mutations. Tumor cells are riddled with genetic mutations not found in healthy cells. Scientists estimate that it takes five to 10 key mutations for a healthy cell to become cancerous.

Some of these mutations can be caused by assaults from the environment, such as ultraviolet rays and cigarette smoke. Others arise from harmful molecules produced by the cells themselves. In recent years, researchers have begun taking a closer look at these mutations, to try to understand how they arise in healthy cells, and what causes these cells to later erupt into full-blown cancer.

Continue reading “Researchers Explore a Cancer Paradox” →