image of Niagara Falls

image of Niagara Falls Niagara Falls is comprised of three waterfalls, the largest of which is Horseshoe Falls. Straddling the border between the USA and Canada, the water cascades. The first signs of life emerged on Earth in the form of microbes about 4 billion years ago. While scientists are still determining exactly when and how these microbes appeared, it’s clear that the emergence of life is intricately intertwined with the chemical and physical characteristics of early Earth.