How long have humans lived on Earth?
4. How long has life existed on Earth? The oldest known fossils are approximately 3.5 billion years old, but some scientists have discovered chemical evidence suggesting that life may have begun even earlier, nearly 4 billion years ago. 6. How long ago did humans become human? The oldest known hominid, or humanlike species, has been dated at 4.4 million years old. Another species, which is yet to be confirmed as a hominid, has been dated at 6 million years old. Scientists estimate that the hominid lineage diverged from the ape lineage 5 to 8 million years ago. Homo sapiens, the species to which we belong, has existed for about 100,000 years.
