The sea sponge is the first animal on Earth according to MIT scientists who recently published a research paper in the Proceedings of the National Academy of Sciences.
Lead author of the paper, David Gold who is a postdoc in the Department of Earth at the Massachusetts Institute of Technology conducted a series of genetic tests to understand pre-Cambrian evolution. The results of the tests suggest that molecules which are produced by the plain sea sponge are present in rocks that are 640 million years old. Thus, the sea sponge would be the world’s oldest animal to date.
During the Cambrian era a booming evolution process was experienced on our planet. 540 million years ago marked the beginning of the Cambrian era and the emergence of animal organisms on the planet. From here onwards, unicellular organisms developed into multicellular organisms at a rapid pace. The trove of fossils from this period offers a great variety of clues as to an evolution timeline.
However, the pre-Cambrian era is little understood. Now, thanks to the MIT scientific team working with the Department of Earth, Atmospheric and Planetary Sciences, the sea sponge is in the spotlight. David Gold explained:
“We brought together paleontological and genetic evidence to make a pretty strong case that this really is a molecular fossil of sponges. This is some of the oldest evidence for animal life.”
A recent scientific debate asked whether the sea sponge or the comb jelly are the world’s oldest animal. The evidence brought forth by David Gold and MIT professor Roger Summons tilts the balance in the favor of the sea sponge. How did the MIT scientific team come to the conclusion that the sea sponge is the first animal on Earth?
Paleontological evidence in the form of 640 million-year-old rocks was first brought to analysis. Some of these ancient rocks contain high levels of a lipid molecule resembling cholesterol. At the time, sea sponges would have been the only organisms capable of producing this molecule. Prior to the Cambrian explosion of animal life, evolution is rather blurred.
However, molecular fossils can now provide a number of answers to the scientific community’s most puzzling questions. The Cambrian explosion of animal life should have been supported by evolution before the Cambrian era. Molecular fossils and biomarkers suggest that the MIT team was right in assuming that the sea sponge is the first animal on Earth.
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