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Scientists May Have Found the Earliest Evidence of Life On Earth (sciencemag.org)
sciencehabit writes with news that UCLA scientists have found evidence that life likely existed on Earth at least 4.1 billion years ago, 300 million years earlier than previously thought. Science reports: "When did life on Earth begin? Scientists have dug down through the geologic record, and the deeper they look, the more it seems that biology appeared early in our planet's 4.5-billion-year history. So far, geologists have uncovered possible traces of life as far back as 3.8 billion years. Now, a controversial new study presents potential evidence that life arose 300 million years before that, during the mysterious period following Earth's formation. The clues lie hidden in microscopic flecks of graphite—a carbon mineral—trapped inside a single large crystal of zircon. Zircons grow in magmas, often incorporating other minerals into their crystal structures of silicon, oxygen, and zirconium. And although they barely span the width of a human hair, zircons are nearly indestructible. They can outlast the rocks in which they initially formed, enduring multiple cycles of erosion and deposition."
Let's not even include a link to it!
Note that 4.1 Ga is right in the middle of the Hadean period, when the Earth was still settling into layers and the crust and oceans were just forming. No distinct core or mantle yet, and the moon was a ring of rock encircling the Earth. This is half a million years before plate tectonics, before even prokaryota (micros without cell nuclei) developed.
These clues might just tell _how_ cellular reproduction and upwards energy gradients (i.e. life) began, not just _when_.
It is dangerous to be right when the government is wrong.