The riches of the natural world are not spread evenly across the globe. Some places, such as the tropical Andes in South America, are simply stacked with unique species of plants and animals, many found no place else on Earth. So-called biodiversity “hotspots” are thought to cover just 2.3 percent of the planet’s surface, mostly in the tropics, yet they account for half of all known plant species and 77 percent of land vertebrates.
Contrary to popular belief, becoming a fossil can be easy instead of hard, and fossils can be abundant instead of rare. It all depends on what an organism is made of, where it lives and dies, and what happens next in the dust-to-dust process—preservation or natural recycling. Continue reading How Do Fossils Form?
Hundreds of millions of years ago, massive ice caps sheathed Earth’s continents from coast to coast. Only the peaks of the planet’s mountains stood above the ice as glaciers ground and crushed their way through the bedrock, meandering slowly toward the snow-covered plains. Where the glaciers met the oceans, huge blocks of ice and rock calved from the glaciers and dropped into the sea. Life, mostly algae, cyanobacteria and other bacteria, somehow persisted in the small ice-free pockets of ocean water. Like an icy planet in a distant solar system, Earth during its formative years, a juvenile phase known as the “Snowball” Earth, was a far different place than the mostly blue planet of today. Continue reading How Does Earth’s Carbon Cycle Work?
Spiders that travel on the wind are also adept sailors when they land on water, researchers have discovered.
Morito Hayashi, a spider researcher at the Natural History Museum in London, says that it had been assumed that a wet landing would be deadly for what are known as ballooning spiders—those that drift to new habitats on wind-blown silken threads that they spin to lift themselves aloft.