Life’s Role in Shaping Our World

A recent scientific study traces the co-evolution of Earth’s atmosphere, oceans, and life over 500 million years, revealing how organisms like algae have modified and adapted to changing environmental conditions, ultimately enhancing Earth’s habitability.

Over the past 500 million years, interactions between the atmosphere, the ocean, and life on Earth have created conditions that allowed early organisms to thrive. An interdisciplinary team of scientists has now published a perspective article on this co-evolutionary history in the multidisciplinary open-access journal National Science Review.

“One of our tasks was to summarize the most important discoveries about carbon dioxide and oxygen in the atmosphere and ocean over the past 500 million years,” says Syracuse University geochemistry professor Zunli Lu, lead author on the paper. “We reviewed how those physical changes affected the evolution of life in the ocean. But it’s a two-way street. The evolution of life also impacted the chemical environment. It is not a trivial task to understand how to build a habitable Earth over long time scales”

The team from Syracuse University, Oxford University, and Stanford University explored the intricate feedbacks among ancient life forms, including plants and animals, and the chemical environment in the current Phanerozoic Eon, which began approximately 540 million years ago.

Environmental Feedback and Early Life

At the start of the Phanerozoic, carbon dioxide levels in the atmosphere were high, and oxygen levels were low. Such a condition would be difficult for many modern organisms to thrive. But ocean algae changed that. They absorbed carbon dioxide from the atmosphere, locked it into organic matter, and produced oxygen through DOI: 10.1093/nsr/nwae099