Although single-celled creatures had been reigning on Earth for billions of years, a major shift occurred when multicellular beings emerged (aka complex life forms). A first step was when cells started to organize themselves into new three-dimensional structures and ultimately leading to the emergence of mammals like ourselves.
Researchers found chemical traces in ancient rocks and decided that it’s a good idea to recreate them. By studying chemical biomarkers, scientists from Caltech and The Australian National University (ANU), Max Planck Institute are showing that complex life evolved much later on Earth than previously thought.
First forms of multicellular life evolved 100 million years later than initially thought
During an MIT study from 2009, chemicals from rocks located in Oman were analyzed, and the conclusion was that the first forms of complex life evolved 635 million years ago.
Researchers from MIT have used ‘biomarkers’ to try to bridge a 340 million year gap between the molecular clock and actual fossil evidence. They also found evidence of a sponge biomarker within rocks dating back 635 million years. According to the new research, other mechanisms except for sponges could produce those biomarkers.
Dr Lennart van Maldegem, who is a co-author of one of the linked studies into the origins of biomarkers from the ancient rocks, declared:
It brings the oldest evidence for animals nearly 100 million years closer to the present day,
We were able to demonstrate that certain molecules from common algae can be altered by geological processes – leading to molecules which are indistinguishable from those produced by sponge-like animals.
Therefore, the earliest date for the start of complex life on Earth switches to about 560 million years ago, a period when bacteria and green algae were representing something common for the world’s seas. Also, the acritarchs, planktonic single-celled algae of uncertain affinity were also dominating the planet.
The two new studies were published in Nature Ecology and Evolution.