"Link Found Between Earth's Oxygen and Evolution of Animals"
A new study suggests that sulfate, rather than phosphorus, was the main control in the oxygenation of the planet during the first major evolution of complex life, which could explain the prolonged low levels of oxygen throughout Earth's history and the late evolution of animal life on Earth. The study also holds implications about the possibility of intelligent life on other planets, suggesting that planets around stars larger than the sun may not develop complex intelligent life due to the relatively short lifetime of large stars.