Scientists Unearth Ancient Evidence on the Origins of Life, Dating Back 1.75 Billion Years

There’s a major discovery that sheds new light on the origins of life on Earth.

Scientists have found the oldest direct proof of oxygenic photosynthesis, the process of converting sunlight into energy and oxygen, in fossilized bacteria from Australia and Canada. 

These fossils, dating back 1.75 billion years, push back the confirmed origin of photosynthesis as we know it by at least 1.2 billion years.1

Photosynthesis in Life’s Development

Scientists Unearth Ancient Evidence on the Origins of Life, Dating Back 1.75 Billion Years » photosynthesis dp10457997
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Photosynthesis is essential for life as it produces available oxygen, which is vital for most organisms. While scientists believe photosynthesis originated about 3.5 billion years ago, it was initially a primitive form that didn’t produce oxygen.(ref) 

The transition to oxygen-producing photosynthesis, which is now dominant, remains unclear.

Cyanobacteria & the Rise of Oxygen

Scientists Unearth Ancient Evidence on the Origins of Life, Dating Back 1.75 Billion Years » cyanobacteria ss1433998760
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Cyanobacteria are thought to be among the first organisms to perform oxygenic photosynthesis using thylakoid membranes, structures inside their cells where this process occurs. 

Their oxygen production led to the Great Oxygenation Event, which changed Earth’s chemistry and paved the way for breathing life into Earth.(ref)

Finding Thylakoid Membranes in Ancient Fossils

Scientists Unearth Ancient Evidence on the Origins of Life, Dating Back 1.75 Billion Years » cyanobacteria wc
Image Credit: Tuomas Huokko, Tao Ni, Gregory F. Dykes, Deborah M. Simpson, Philip Brownridge, Fabian D. Conradi, Robert J. Beynon, Peter J. Nixon, Conrad W. Mullineaux, Peijun Zhang & Lu-Ning Liu, CC BY 4.0, via Wikimedia Commons

Researchers discovered thylakoid membranes, the direct evidence of oxygenic photosynthesis, in 1.75 billion-year-old fossils from the McDermott Formation in Australia and one billion-year-old fossils from the Grassy Bay Formation in Arctic Canada. 

This finding provides valuable insights into the evolution of complex life on Earth.(ref)

Challenges in Fossil Preservation & Analysis

Scientists Unearth Ancient Evidence on the Origins of Life, Dating Back 1.75 Billion Years » What Types of Ancient Structures Were Discovered ss1955212840
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Finding and analyzing such ancient fossils is challenging. Bacteria are soft-bodied organisms that don’t fossilize well, and the fossils are tiny, making them difficult to locate.(ref) Furthermore, the compression of sediment and rock over time can destroy delicate structures like thylakoid membranes.(ref)

Understanding Life on Earth & Beyond

Scientists Unearth Ancient Evidence on the Origins of Life, Dating Back 1.75 Billion Years » thylakoid dp625728368
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The discovery of these ancient thylakoid membranes is significant as it helps scientists understand the evolution of complex life on Earth. 

It also has implications for searching for signs of life on other planets by providing clues about the potential existence of photosynthesis in different environments.

Source:

  1. Nature
Martha A. Lavallie
Martha A. Lavallie
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Martha is a journalist with close to a decade of experience in uncovering and reporting on the most compelling stories of our time. Passionate about staying ahead of the curve, she specializes in shedding light on trending topics and captivating global narratives. Her insightful articles have garnered acclaim, making her a trusted voice in today's dynamic media landscape.