Abstract: The famous evolutionary biologist Charles Darwin considered Life on Earth a continuum since its advent. In 1859, he propounded his theory of Evolution based on his observations on the incredible voyage on HMS Beagle. In his book, On the Origin of Species, Darwin could demonstrate and explain that every complex life form had a simple predecessor form, giving rise to complex life forms after accumulating advanced characters. But he could not explain how the complexity in life forms suddenly appeared in the Cambrian and younger rock records. Compared to nearly 4400 million years of Earth's history, only 538 million years, called the Phanerozoic period, saw the appearance of diverse complex life forms as we see them today. This sudden appearance is known as the ‘Cambrian Explosion’. He admitted in his book that he could not explain this sudden appearance of complex forms in the fossil record. Since then, the evolution and extinction of life have been going on.
Darwin's question, "What happened before the Cambrian?" set the stage for further exploration and discovery. This question led to the establishment of a new science in palaeontology: Precambrian Palaeobiology. The pace of inquiry into Precambrian-age rock strata and discovery was slow in the early phase because finding evidence of early life forms was challenging. Suitable rocks were not known, and there was no idea where to look for the possible cryptic life of the Precambrian Eon.
India is one of the few countries where suitable Archaean metasedimentary rocks are available for examination; Proterozoic successions offer continuous rock records of Mesoproterozoic and Neoproterozoic successions. In these rock records, Indian researchers have documented age diagnostic fossils and some of the critical metabolic steps of the life form that gave rise to complexity noted in the Phanerozoic rock records. This talk traces the history of Precambrian Palaeobiology on a global scale, the evidence gathered from the Indian Precambrian successions over the last 75 years, and their significance in understanding evolution and antiquity of life forms on Earth.
About the speaker: Dr. Mukund Sharma is CSIR Emeritus Professor at Integral University, Lucknow, and former Scientist ‘G’ at the Birbal Sahni Institute of Palaeosciences, Lucknow. He has been recognized with several prestigious awards, including the Bhartiya Bhasha Samman by the BBP Rashtriya Parishad, the 2023 Dr. Anil Chandra Award for Excellence in Palaeontology by the Geological Survey of India, Bengaluru, and the 2018 L. Rama Rao Birth Centenary Award by the Geological Society of India. Prof. Sharma is a Fellow of multiple esteemed scientific bodies: the Indian Social Science Academy, the Geological Society of India, the Palaeontological Society of India, the Palaeobotanical Society of India, and the Indian Association of Sedimentologists. "He has successfully supervised 9 doctoral theses and has published over 146 research papers in reputed scientific journals.