The controversy over early-Archaean microfossils

摘要

Few events in early earth history-whether they were concerned with the chemical, physical or biological aspects of the planet's evolution - have remained undebated, emerging views uncontested and which did not polarize the debating scientists into differing groups. The latest example is about discoveries of ancient fossils from the Archaean (2.5-3.8 b.y. period) which have generated much controversy about their authenticity and antiquity. Palaeontologists were undoubtedly excited when these discoveries were first reported, since these helped to modify the view that the Archaean era represented an 'azoic' or lifeless geological time. Besides bringing about this change in their perspective, the finds also infused fresh 'life' to fossil studies and shifted the emphasis from conventional approaches based on geology or morphology to sophisticated analytical techniques to solve not only problems about biogenecity or antiquity, but also enhance our understanding of organic metamorphism and biochemical evolution of the organisms. Though plenty of new data emerged from these innovative approaches, they also triggered a fresh volley of debates.