The theory of plate tectonics explains many earth features, like ocean floor trenches and sediment-free mid-ocean ridges made of hardened magma. The popular theory holds that continents drift slowly across earth's surface atop deeply buried molten rock, and that plate movements creep along at leisurely paces. But new research by Yale University geologists calls that into question.

Mosasaur fossils have been recovered from Late Cretaceous rocks all over the world. Most are just a fossilized tooth or perhaps a loose rib or vertebra. Occasionally, several bones are discovered still together. Conventional wisdom holds that creatures from this period died millions of year ago. If that's true, why do some still have soft tissue?

Sponges have long been considered one of the "simplest" forms of life. Now an international team of scientists has analyzed sponge DNA and concluded that it shares representative genes associated with the core processes of all animal cells--including human cells. What does this say about where sponges and people came from?

Humans are in rare company when it comes to singing duets. Humpback whales perform original couples' songs, as do a handful of birds. It was thought that bird duets were just for mating purposes, but a study on zebra finches has opened a new window on bird behavior.