A recent Virginia Tech analysis has pushed the timeline of life’s origin back nearly 2 billion years. Researchers, led by Shuhai Xiao, have extended our understanding of ancient life to the Proterozoic Eon, a period spanning 2,500 million to 539 million years ago.
Fossil evidence previously documented evolutionary milestones over the past half-billion years, but this new study provides a more complete picture of life’s origin. The team found that eukaryotes first appeared at least 1.8 billion years ago and remained relatively stable for the next billion years, with little change in species diversity.
However, around 720 million to 635 million years ago, Earth experienced severe ice ages, known as Snowball Earth events. This global glaciation had a significant impact on eukaryotic species, leading to rapid turnover of species after the thawing of the planet.
The study sheds new light on the complex relationship between environmental and evolutionary forces that influenced the development of life on Earth. Scientists are now pondering how changes in climate, rising atmospheric oxygen levels, competition among organisms, and other factors may have triggered this evolutionary surge.
This research provides a detailed framework for exploring unanswered questions about Earth’s ancient past and offers valuable insights into how living organisms interacted with their environment over billions of years. The findings are published in the journal Science.
Source: https://www.earth.com/news/timeline-of-lifes-evolution-extended-by-nearly-1-5-billion-years