When a female animal compares males to choose a mate, she can't order a laboratory genetic screen for each suitor. Instead, she has to rely on external cues that may indicate genetic quality. Until now, biologists have focused on elaborate ornaments, such as the peacock's tail, as cues that females might use.

An hour from now, will you remember reading this? It all depends on proteins in your brain called NMDA receptors, which allow your neurons to communicate with each other.

Vertebrate creatures first began moving from the world's oceans to land about 415 million years ago, then all but disappeared by 360 million years ago. The fossil record contains few examples of animals with backbones for the next 15 million years, and then suddenly vertebrates show up again, this time for good.

There's growing evidence that the dinosaurs and most their contemporaries were not wiped out by the famed Chicxulub meteor impact, according to a paleontologist who says multiple meteor impacts, massive volcanism in India, and climate changes culminated in the end of the Cretaceous Period.

Queen's University researchers have discovered that seeking out the most attractive mate may be unhealthy for any offspring.

In a study of orangutans living on the Indonesian islands of Borneo and Sumatra, scientists from Duke University and the University of Zurich have found what they say is the first demonstration in primates of an evolutionary connection between available food supplies and brain size.

Soil from a Copper Age site in northern Kazakhstan has yielded new evidence for domesticated horses up to 5,600 years ago. The discovery, consisting of phosphorus-enriched soils inside what appear to be the remains of horse corrals beside pit houses, matches what would be expected from Earth once enriched by horse manure. The Krasnyi Yar site was inhabited by people of the Botai culture of the Eurasian Steppe, who relied heavily on horses for food, tools, and transport.

One of the most colorful birds in the world may have a less-than-colorful future. Macaws, the largest members of the parrot family, have seen their numbers decline in recent decades, and that trend is continuing today.

Can nuclear energy save us from global warming? Perhaps, but the tradeoffs involved are sobering: thousands of metric tons of nuclear waste generated each year and a greatly increased risk of nuclear weapons proliferation or diversion of nuclear material into terrorists' hands.

A person suffering from tennis elbow may not have to look any further than his or her own body for the most effective treatment, according to a study published in the November issue of The American Journal of Sports Medicine.

By studying the humble honey bee, researchers at the University of Illinois at Urbana-Champaign have come a step closer to understanding the molecular basis of social behavior in humans.