It took a half billion or more years for life to emerge; a billion years later the earliest forms of blue-green algae (which are actually bacteria) and simple fungi were generated. The first sponge-like animals emerged 650 million years ago, land plants about 500 million years ago, the first land animals 400 million years ago. The earliest human ancestors only three million years ago, human beings as we know them now emerged only 35,000 years ago, human “civilization” only four thousand years
