Way back in the dim and distant past in that vast expanse of pre-'Creation Week' history of life on Earth, simple bacteria were evolving a way to use the energy in sunlight to turn the carbon dioxide in the atmosphere into the basic building block of carbohydrates, glucose.
The process that was evolving was destined to transform life on Earth when the 'cyanobacteria' took up residence in archaea and turned them into simple algae, the progenitors of all plant-life on earth and responsible for so much greenery away from desert and polar regions.
And now scientists working at the Early Life Traces & Evolution laboratory of the Astrobiology Research Unit at Liège University (ULiège), Belgium have pushed back the earliest date for these pioneer bacteria in the fossil record to 1.75 Billion years by identifying thylakoids membranes, essential for early photosynthesis, in microfossils in rock formations in Australia, Democratic Republic of Congo and Canada.
Their discovery is explained in a ULiège press release:
Researchers at the University of Liège (ULiège) have identified microstructures in fossil cells that are 1.75 billion years old. These structures, called thylakoid membranes, are the oldest ever discovered. They push back the fossil record of thylakoids by 1.2 billion years and provide new information on the evolution of cyanobacteria, which played a crucial role in the accumulation of oxygen on the early Earth. This major discovery is presented in the journal Nature.Sadly, the team's paper in Nature is behind a paywall but the abstract is available:
Catherine Demoulin, Yannick Lara, Alexandre Lambion and Emmanuelle Javaux from the Early Life Traces & Evolution laboratory of the Astrobiology Research Unit at ULiège examined enigmatic microfossils called Navifusa majensis (N.majensis) in shales from the McDermott Formation in Australia, which are 1.75 billion years old, and in 1 billion year old formations of DRCongo and arctic Canada. Ultrastructural analyses in fossil cells from 2 formations (Australia, Canada) revealed the presence of internal membranes with an arrangement, fine structure and dimensions permitting to interpret them unambiguously as thylakoid membranes, where oxygenic photosynthesis occurs. These observations permitted to identify N majensis as a fossil cyanobacterium. This discovery puts into perspective the role of cyanobacteria with thylakoid membranes in early Earth oxygenation. They played an important role in the early evolution of life and were active during the Great Oxygenation Event (GOE), around 2.4 billion years ago. However, the chronology of the origins of oxygenic photosynthesis and the type of cyanobacteria (protocyanobacteria? With or without thylakoids?) involved remain debated, and the ULiège researchers' discovery offers a new approach to clarify these issues. "The oldest known fossil thylakoids date back to around 550 million years. The ones we have identified therefore extend the fossil record by 1.2 billion years", explains Professor Emmanuelle Javaux, paleobiologist and astrobiologist, director of the Early Life Traces & Evolution laboratory at ULiège. "The discovery of preserved thylakoids in N. majensis provides direct evidence of a minimum age of around 1.75 billion years for the divergence between cyanobacteria with thylakoids and those without." But the ULiège team's discovery raises the possibility to discover thylakoids in even older cyanobacterial fossils, and to test the hypothesis that the emergence of thylakoids may have played a major role in the great oxygenation of the early Earth around 2.4 billion years ago. This approach also permits to examine the role of dioxygen in the evolution of complex life (eucaryote) on our planet, including the origin and early diversification of algae that host chloroplasts derived from cyanobacteria. "Microscopic life is beautiful, the most diverse and abundant form of life on Earth since the origin of life. Studying its fossil record using new approaches will enable us to understand how life evolved over at least 3.5 billion years. Some of this research also tells us how to search for traces of life beyond Earth!", concludes Emmanuelle Javaux.
Abstract
Today oxygenic photosynthesis is unique to cyanobacteria and their plastid relatives within eukaryotes. Although its origin before the Great Oxidation Event is still debated1,2,3,4, the accumulation of O2 profoundly modified the redox chemistry of the Earth and the evolution of the biosphere, including complex life. Understanding the diversification of cyanobacteria is thus crucial to grasping the coevolution of our planet and life, but their early fossil record remains ambiguous5. Extant cyanobacteria include the thylakoid-less Gloeobacter-like group and the remainder of cyanobacteria that acquired thylakoid membranes6,7. The timing of this divergence is indirectly estimated at between 2.7 and 2.0 billion years ago (Ga) based on molecular clocks and phylogenies8,9,10,11 and inferred from the earliest undisputed fossil record of Eoentophysalis belcherensis, a 2.018–1.854 Ga pleurocapsalean cyanobacterium preserved in silicified stromatolites12,13. Here we report the oldest direct evidence of thylakoid membranes in a parallel-to-contorted arrangement within the enigmatic cylindrical microfossils Navifusa majensis from the McDermott Formation, Tawallah Group, Australia (1.78–1.73 Ga), and in a parietal arrangement in specimens from the Grassy Bay Formation, Shaler Supergroup, Canada (1.01–0.9 Ga). This discovery extends their fossil record by at least 1.2 Ga and provides a minimum age for the divergence of thylakoid-bearing cyanobacteria at roughly 1.75 Ga. It allows the unambiguous identification of early oxygenic photosynthesizers and a new redox proxy for probing early Earth ecosystems, highlighting the importance of examining the ultrastructure of fossil cells to decipher their palaeobiology and early evolution.
Demoulin, C.F., Lara, Y.J., Lambion, A. et al.
Oldest thylakoids in fossil cells directly evidence oxygenic photosynthesis. Nature (2024). https://doi.org/10.1038/s41586-023-06896-7
© 2024 Springer Nature Ltd.
Reprinted under the terms of s60 of the Copyright, Designs and Patents Act 1988.
And another team of scientists unwittingly refute creationism simply by revealing some facts about the world and the history of life on it - a history that has a geological and archaeological record going back to billions of years before creationism's 'Creation Week',
But that's just one more small pebble on the mountain of evidence creationists need to ignore to retain their childish superstition for fear a magic, mind-reading sky bogey will get angry with them. It would be cute if only children believed such absurdities but, apparently, there are even grown adults who still suffer from that psychosis.
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