Is this the Oldest Evidence of Life on Earth?

Fagjun | Published 2017-03-02 02:07

Scientists may have found Earth's oldest evidence of life in bacteria fossils in Canada.

On March 1, 2017, a team of researchers published a study on possible fossilized bacteria in Nuvvuagittuq, a rock formation that stretches out along the coast of Canada's Hudson Bay. If these fossils are indeed the remains of bacteria, there will be evidence that life existed on Earth as early as at least 3.77 billion years ago.

The researchers were Ph.D. student Matthew Dodd, Dr. Dominic Papineau, and a team of researchers from University College London. They aimed to find fossils that could be older than the 3.7 billion-year-old bacteria fossils found in Greenland last year.

The fossils found on Nuvvuagittuq come in filaments, tubes, squiggles on the rock. According to past research, hydrothermal vents are conducive to the formation of rocks like those found on Nuvvuagittuq. Hydrothermal vents are commonly home to signs of bacterial life from billions of years ago. This makes it likely that the fossils found in Nuvvuagittuq are indeed those of early life.

Scientists tested rocks from Nuvvuagittuq to see if there are chemical traces of bacterial remains.

The fossilized bacteria are contenders for the earliest life on Earth, and they are also apparently quite advanced. Based on the shapes of the fossils, Dodd concludes that these bacteria were more complex than expected. “These features show life had evolved beyond a simple cell occurring by itself — like a protocell,” claims Dodd.

Scientific Debate

However, many experts remain skeptical. Research regarding the origin of life on Earth is often subject to heated debate in the scientific community. These newest findings are no different. “I am frankly dubious,” says Frances Westall, the director of research at the CNRS-Centre de Biophysique Moléculaire. Westall argues that the filaments found in Nuvvuagittuq are too big, and other scientists have also expressed doubt.

Another criticism is rooted in the fact that the Nuvvuagittuq rocks were formed under extremely high temperatures. In these conditions, fossils are very unlikely to survive. However, Dr. Papineau argues that the Nuvvuagittuq rocks are made of chert, a very hard material that can possibly protect bacteria from extreme conditions.

The Next Steps

It may be years yet before the scientific community reaches a consensus on the Nuvvuagittuq fossils. If proven, these findings will confirm that life on Earth started quite early, not long after the formation of the planet. These findings can also impact the way scientists understand the evolution of life on Earth. If the fossils do indeed contain bacterial remains that are at least 3.77 billion years old, there will be evidence that life on Earth began and diversified quite quickly.

To further their research, the team will be traveling around the world to other rock formations similar to Nuvvuagittuq. They plan on finding and studying the origins of organic matter on these rocks to see if life was prevalent on Earth or more common around hydrothermal vents 4 billion years ago. Sooner or later, there may be stronger evidence that life began earlier than originally speculated.

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