Early Earth's Atmosphere Could Have Been Half As Thick As Today

Did the young Earth really have a more dense atmosphere, as the current theory goes? Researchers recently used bubbles trapped in rocks to demonstrate that the air 2.7 billion years ago exerted at the most only half the pressure of today’s atmosphere. According to a study published this week in the journal Nature Geoscience, the commonly accepted idea that the early Earth had a thicker atmosphere to compensate for weaker sunlight is wrong. [Read More]

Did The First Monkey Arrive In North America By Raft?

Seven tiny teeth tell the story of an ancient monkey that made a 100-mile trek across the ocean between North and South America into modern-day Panama, the first fossil evidence for the existence of monkeys in North America. The find provides the oldest fossil evidence for the interchange of mammals between South and North America and challenges long-held views of South America as an island continent that evolved in isolation before the Isthmus of Panama was formed and animals began crossing between the continents about 3. [Read More]

Global Mass Extinction: No Species Safe, Say Scientists

According to a new study, dominant species with a population spread around the globe are just as vulnerable in a mass extinction as more fragile species confined to a single locale. In the Earth’s history there has been five mass extinction events, including climate change caused by volcanoes and an asteroid hit 66 million years ago that wiped out the dinosaurs. Generally, geographically widespread animals are less likely to become extinct than animals with smaller geographic ranges, giving them a hedge against regional environmental catastrophes. [Read More]