
Full Text:
Newly discovered fossil evidence from Namibia strengthens the proposition that the world’s first mass extinction was caused by “ecosystem engineers” – newly evolved biological organisms that altered the environment so radically it drove older species to extinction. The event, known as the end-Ediacaran extinction, took place 540 million years ago.
The earliest life on Earth consisted of microbes – various types of single-celled organisms. These held sway for more than 3 billion years, when the first multicellular organisms evolved. The most successful of these were the Ediacarans, which spread around the globe about 600 million years ago. They were a largely immobile form of marine life shaped like discs and tubes, fronds and quilted mattresses.Image credit: Simon Darroch/Vanderbilt
