For almost four billion years life had dawdled along without any detectable ambitions in the direction of complexity, and then suddenly, in the space of just five or ten million years, it had created all the basic body designs still in use today.
For nearly four billion years, life on Earth existed without any significant push toward complexity, evolving in a relatively simple manner. However, a remarkable shift occurred over a brief period of five to ten million years, during which life forms rapidly developed the fundamental body structures that continue to be the foundation of biological diversity today. This sudden burst of complexity marked a pivotal moment in the history of life.
This evolutionary leap not only introduced various body designs but also set the stage for future developments in the animal kingdom. Bill Bryson, in his book "A Short History of Nearly Everything," emphasizes the significance of this transition, illustrating how a lengthy period of slow evolution was abruptly followed by a rich variety of life forms that still exist and thrive in different ecosystems around the world.
