Fossils discovered in Morocco are the oldest known remains of Homo sapiens, scientists reported on Wednesday, a finding that rewrites the story of mankind’s origins and suggests that our species evolved in multiple locations across the African continent.

“We did not evolve from a single ‘cradle of mankind’ somewhere in East Africa,” said Philipp Gunz, a paleoanthropologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and a co-author of two new studies on the fossils, published in the journal Nature. “We evolved on the African continent.”

Continue reading “Oldest Fossils of Homo Sapiens Found in Morocco, Altering History of Our Species” →

Climate change will alter the ecosystems that humanity depends upon in the coming century. But given the complexity of the living world, how can you learn what may happen?

A team of Australian scientists has an answer: miniature ecosystems designed to simulate the impact of climate change. The experiments are already revealing dangers that would have been missed had researchers tried to study individual species in isolation.

“If you just take one fish and put it in a tank and see how it responds to temperature, you can imagine that’s a huge simplification of reality,” said Ivan Nagelkerken, an ecologist at the University of Adelaide who is leading the research effort.

Continue reading “To Simulate Climate Change, Scientists Build Miniature Worlds” →

Prehistoric humans — perhaps Neanderthals or another lost species — occupied what is now California some 130,000 years ago, a team of scientists reported on Wednesday.

The bold and fiercely disputed claim, published in the journal Nature, is based on a study of mastodon bones discovered near San Diego. If the scientists are right, they would significantly alter our understanding of how humans spread around the planet.

The earliest widely accepted evidence of people in the Americas is less than 15,000 years old. Genetic studies strongly support the idea that those people were the ancestors of living Native Americans, arriving in North America from Asia.

Continue reading “Humans Lived in North America 130,000 Years Ago, Study Claims” →

The oldfield mouse doesn’t seem extraordinary. With soulful black eyes and tiny teacup ears, the rodent lives a humdrum life scurrying about meadows and beaches in the Southeast.

But field biologists have long known that when it comes to sex and family life, this mouse is remarkable: Peromyscus polionotus is monogamous — an exception among mammals — and a solicitous parent.

Fathers and mothers will dig burrows together and build elaborate nests when pups are on the way; after they’re born, the father will help tend to the pups, retrieving them when they fall out of the nest, licking them, and huddling to keep them warm.

Continue reading “Why Are Some Mice (and People) Monogamous? A Study Points to Genes” →

For decades, scientists have been trying to figure out what all the carbon dioxide we have been putting into the atmosphere has been doing to plants. It turns out that the best place to find an answer is where no plants can survive: the icy wastes of Antarctica.

As ice forms in Antarctica, it traps air bubbles. For thousands of years, they have preserved samples of the atmosphere. The levels of one chemical in that mix reveal the global growth of plants at any point in that history.

“It’s the whole Earth — it’s every plant,” said J. Elliott Campbell of the University of California, Merced.

Continue reading “Antarctic Ice Reveals Earth’s Accelerating Plant Growth” →