The animal kingdom got off to a slow start. Studies on DNA indicate that the first animals evolved more than 750 million years ago, but for well over 200 million years, they left a meager mark on the fossil record. As best as paleontologists can tell, the animal kingdom during that time consisted of little more than sponges and other creatures rooted to the ocean floor.

But then, about 520 million years ago during the Cambrian Period, animal evolution shifted into high gear. Fast-moving predators, scavengers and burrowers evolved. Many of the major living groups of animals left their first fossils during this so-called Cambrian explosion, including our own ancestors.

Continue reading “The Cambrian Explosion’s Strange-Looking Poster Child” →

Certain people, researchers have discovered, can’t summon up mental images — it’s as if their mind’s eye is blind. This month in the journal Cortex, the condition received a name: aphantasia, based on the Greek word phantasia, which Aristotle used to describe the power that presents visual imagery to our minds.

I find research like this irresistible. It coaxes me to think about ways to experience life that are radically different from my own, and it offers clues to how the mind works.

And in this instance, I played a small part in the discovery.

Continue reading “Picture This? Some Just Can’t” →

In July 1996, two college students were wading in the shallows of the Columbia River near the town of Kennewick, Wash., when they stumbled across a human skull.

At first the police treated the case as a possible murder. But once a nearly complete skeleton emerged from the riverbed and was examined, it became clear that the bones were extremely old — 8,500 years old, it would later turn out.

The skeleton, which came to be known as Kennewick Man or the Ancient One, is one of the oldest and perhaps the most important — and controversial — ever found in North America. Native American tribes said that the bones were the remains of an ancestor and moved to reclaim them in order to provide a ritual burial.

Continue reading “New DNA Results Show Kennewick Man Was Native American” →

For centuries, archaeologists have reconstructed the early history of Europe by digging up ancient settlements and examining the items that their inhabitants left behind. More recently, researchers have been scrutinizing something even more revealing than pots, chariots and swords: DNA.

On Wednesday in the journal Nature, two teams of scientists — one based at the University of Copenhagen and one based at Harvard University — presented the largest studies to date of ancient European DNA, extracted from 170 skeletons found in countries from Spain to Russia. Both studies indicate that today’s Europeans descend from three groups who moved into Europe at different stages of history.

Continue reading “DNA Deciphers Roots of Modern Europeans” →