With a skull of 3 million years, scientists have been able to prove the existence of Australopithecus afarensis, the oldest ancestor of humanity. 4 million years ago, humanity did not exist. But at least one creature bore in its bones what would be the hallmark of Homo sapiens. Australopithecus afarensis, that creature's name, had a tiny brain. But it stood like no monkey could do, representing an ancestral trait that would be passed from generation to generation to modern man.
Estuaries filter out sediments and pollutants from rivers and streams before they flow into the ocean, providing cleaner waters for humans and marine life.
