“We’ve learned,” he says, “that over the history of our planet, Earth and life have co-evolved. Changes in the environment affect life, and changes in life can transform the environment. This is a lesson to ponder as we think about our future as well as our past.”

—Andrew H. Knoll PhD—

From—Cambrian Ocean World: Ancient Sea Life of North America (Life of the Past).****couldn’t find this title****”