In fourteen hundred ninety-two, Columbus sailed the ocean… purple?
Sounds crazy, but that’d be the rhyme if Columbus was around 1.8 billion years ago, according to scientists.
Scientists have differed in opinion on what was happening to the Earth’s oceans when oxygen levels began to rise during the mid-Proterozoic period.
The main theory is that higher oxygen levels caused the prevalent iron formations to disappear, while opposing arguments maintain that the oceans were either oxygen or sulfur-rich. Either theory can be explained by the dwindling iron.
However, evidence for a sulfur-rich ocean has disrupted popular thinking.
Professors at the Australian National University uncovered 1.64 billion-year-old molecular fossils close to the Barney Creek formation of the McArthur Basin.
The fossilized eukaryotes were complex life forms containing a nucleus which evolved into our modern plant and animal life. The purple and green pigments they found on the fossils point towards phototrophic sulfur bacteria.
Jochen Brocks, who is leading the study, says, “The ocean north of Australia may indeed have been vastly anoxic, toxic for complex life and colored with a shade of purple.”
Brocks explained further that the ecosystem of the ocean at that time was vastly different from the oxygen-heavy water that makes up three-fifths of our planet.
“If indeed the oceans were sulfidic during this middle period of Earth’s history,” Brock continued, “it would rewrite much of what we’ve believed about a fifth of the planet’s history.”
The group of scientists suggests the Earth was practically made up of nitrogen and copper, elements necessary for life. This explains why the world was full of bacteria almost 2 billion years ago.
As technology advances every day, scientists hope to uncover more of the third rock from the sun’s hidden history. The new findings beg the question, if we have been wrong about what has led to our home planet’s current history, then what else have we failed to understand?