Virginia Tech researchers have traced the evolution of life back nearly 2 billion years, revealing a slower pace of change during the "boring billion" period and a subsequent diversification following global ice ages. Their study, published in the journal Science, analyzes the rise and fall of ancient species over millions of years, expanding our understanding of life’s timeline beyond the last 500 million years to include the Proterozoic Eon (2,500 to 539 million years ago). This eon primarily featured smaller, soft-bodied marine eukaryotes, whose fossils are scarce.
Lead researcher Shuhai Xiao and colleagues conducted a high-resolution analysis of global fossil data, allowing them to chart fluctuations in species diversity. Their findings suggest that eukaryotes emerged no later than 1.8 billion years ago, exhibiting low turnover rates during the "boring billion." However, cataclysmic events like the Snowball Earth ice ages prompted a rapid increase in evolutionary dynamics post-glaciation. These insights raise questions about the environmental and evolutionary factors that influenced the changing rates of evolution throughout history. The research not only sheds light on ancient life but also sets a framework for future studies in evolutionary biology.
