According to the most widely accepted theories, evolutionary biologists assert that life on Earth began roughly 4 billion years ago, beginning with single-celled bacteria and gradually giving way to more complex organisms. According to this same evolutionary timetable, the first complex organisms emerged during the Neoproterozoic era (ca. 800 million years ago), which took the form of fungi, algae, cyanobacteria, and sponges.
However, due to recent findings made in the Arctic Circle, it appears that sponges may have existed in Earth’s oceans hundreds of millions of years earlier than we thought! These findings were made by Prof. Elizabeth Turner of Laurentian University, who unearthed what could be the fossilized remains of sponges that are 890 million years old. If confirmed, these samples would predate the oldest fossilized sponges by around 350 million years.
Continue reading “Animals Could Have Been Around Hundreds of Millions of Years Earlier Than Previously Believed”
The last few years has seen an explosion of exoplanet discoveries. Some of those worlds are in what we deem the “habitable zone,” at least in preliminary observations. But how many of them will have life-supporting, oxygen-rich atmospheres in the same vein as Earth’s?
A new study suggests that breathable atmospheres might not be as rare as we thought on planets as old as Earth.
Continue reading “Science Fiction Might Be Right After All. There Might Be Breathable Atmospheres Across the Universe”
Billions of years ago, Earth’s environment was very different from the one we know today. Basically, our planet’s primordial atmosphere was toxic to life as we know it, consisting of carbon dioxide, nitrogen and other gases. However, by the Paleoproterozoic Era (2.5–1.6 billion years ago), a dramatic change occurred where oxygen began to be introduced to the atmosphere – known as the Great Oxidation Event (GOE).
Until recently, scientists were not sure if this event – which was the result of photosynthetic bacteria altering the atmosphere – occurred rapidly or not. However, according to a recent study by a team of international scientists, this event was much more rapid than previously thought. Based on newly-discovered geological evidence, the team concluded that the introduction of oxygen to our atmosphere was “more like a fire hose” than a trickle.
Continue reading “About 2.3 Billion Years Ago, a Firehose of Oxygen was Released Into the Atmosphere”