The discovery of living fossils floating in sea water 2.1 billion years ago on the Gabonese geological site, which they have been exploring for fifteen years, constitutes a new major advance in the knowledge of the emergence of multicellular life on Earth.
Abderrazak El Albani has been exploring the rocks of the Gabonese site in the Franceville region for 15 years, and his discoveries continue to upset scientific knowledge of the origins of life on Earth. “We realized in 2008 that there were life forms that shouldn’t have been there.“, he recalls.
The latest research by the international team of twelve researchers he leads has highlighted “the oldest fossils of eukaryotic protists (the first complex cells that make up living things), which lived in seawater 2.1 billion years ago“. The first traces of plankton ever observed.
A new discovery which is the subject of a publication this Tuesday, May 2 in the journal Earth Planetary Sciences Letter.
“Until now, the oldest recognized planktonic eukaryotic protists were dated at 570 million years. This new discovery highlights a biological innovation that raises new questions about the history of evolution, namely: did perfected planktonic life forms already exist 2.1 billion years ago? specifies the CNRS press release announcing the publication.
These delicate creatures resembling marine flying saucers, whose size can reach 4.5 centimeters, would therefore be the first macroscopic planktons to have appeared on Earth. A complex and sophisticated assembly of cells, which has the particularity of including zinc enrichment. Extremely sharp chemical analyzes of the fossils revealed the presence, inside the fossil, of “two and a half times more zinc than on the rock around“, says Abderrazak El Albani. “Thehe zinc is a nutrient that enters into the composition of proteins and DNA, it is essential for biological metabolism” he specifies. A presence of zinc which definitively distinguishes these organisms from bacteria.
These fossils were discovered in the famous Gabonese deposit of Moulendé, which had already delivered the oldest multicellular organisms “Gabionta”. The date of the appearance of multicellular life on Earth had then been pushed back by about 1.5 billion years, from – 600 million to – 2.1 billion years. of a sophisticated, complex life, at -2.1 billion years ago, it was unimaginable until then. These discoveries have really changed our knowledge of the appearance of multicellular life on Earth. And it was not easy to get it accepted by the scientific community, which can be dogmatic. Our results were initially disputed“, specifies the researcher.After 15 years of scientific production, the facts are there, the most reluctant have sided with them and we are very much in demand to visit our collections in Poitiers, or exhibit our fossil specimens in museums around the world.“he rejoices.
Professor El Albani and his team will return to Gabon to continue their research. Over the past fifteen years, they have taken the opportunity to train a dozen Gabonese doctoral students. The objective today is to obtain the definitive classification of the site as a UNESCO World Heritage Site, in order to preserve it from possible looting, and to make this exceptional site available to the world scientific community thanks to to a steering committee for the research programs that could be carried out there.