About time. Readers may recall that the first billion years of life when, we are told, simple microbes dominated, have been considered boring.
Well, books where we have only .01 percent of the text preserved are boring too.
But things may be changing. From Science News:
1.8 billion years ago, low oxygen may not have hindered life after all
After this wild youth of rapid change, things slowed down. About 1.8 billion years ago, the climate stabilized. Oxygen levels steadied. Evolution seemingly stalled. For around a billion years, not a lot changed on planet Earth. Scientists called this interval the dullest time in Earth’s history. It came to be known as the “boring billion.”
But scientists are taking a fresh look at the boring billion and coming up with very different, downright fascinating, alternatives. Recent work recasts the era as a possibly pivotal (and definitely contentious) chapter in the story of life, which took a new twist not long after, with the introduction of animals.
At that time, they say, a supercontinent called Nuna formed and broke up.
Pinpointing when animals could have evolved, based on atmospheric conditions alone, is difficult because estimates of early animals’ oxygen needs are speculative. After millions of years of adaptation, no early animals are alive today to testify. Instead of guessing how ancient animals might have lived, geobiologists Daniel Mills and Donald Canfield of the University of Southern Denmark in Odense and colleagues tested a modern analog: the sea sponge. Their finding challenges the view that low oxygen levels during the boring billion prohibited the evolution of animals, Mills and Canfield wrote last year in BioEssays. More.
If they are there, we may find them. But oxygen is not all that is required to make an animal, so once again, we are running into the information challenge created for Darwinian evolution (natural selection acting on random mutation generates huge levels of information, not noise) .
See also: What we know and don’t, about the origin of life