Who are we?

Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people.
-- Carl Sagan

Who are we? We are just an upright, walking. big-brain, superintelligent big ape. We belong to the family called Hominidi. We are the species called Homo Sapiens Sapiens. We are one species of about 5500 mammalian species that exist on Earth today, one of probably 16 upright-walking apes that have existed, and the only one (except for the bonobos) that exist on Earth today. We evolved from common ancestors with the gorilla, the chimpanzees and the bonobos. We have a common past and we have a common future, and it’s important to remember that all of these great apes have come from an interesting evolutionary journey as we have. It is this journey that has been the focus of the past three generations of my family searching for fossils in Africa. When we find a fossil, we mark it with GPS coordinates, take digital pictures, then begin to excavate it slowly using picks and brushes. Let me take you back to Africa 2 million years ago, to the Rift Valley (If you want to become a fossil, you want to die in a place like the Rift Valley, where flows bring sediments that bury you fast, and later move the terrain so that your bones resurface for people like me to find them). Two million years ago, one of our ancestors lived along Lake Turkana. Homo Erectus (she shows a skull) lived alongside three other species there (picture above). Members of his species later started moving north and east, leaving Africa (90’000 generations ago) and beginning his spread across the globe. Until 30’000 years ago at least three species of hominids lived on Earth.

Who are we today? We are certainly a polluting, wasteful, nasty species, with a few nice things thrown in perhaps. We have a much larger brain than our ape ancestors. Is this a good evolution, or will it lead us to be one of the shortest-living species on Earth? What makes us different is our collective intelligence. We have reached an extraordinary number of people on this planet. We are certainly the only animal that makes conscious decisions that are bad for our species. It’s important to remember that we all have an African origin. We have a common past and share a common future. Evolutionarily speaking we are just a blip, sitting on the edge of a precipice. But we have the tools and the technology to communicate what needs to be done to hold it together. Will we do that?
-- Louise Leakey

Louise Leakey asks, "Who are we?" The question takes her to the Rift Valley in Eastern Africa, where she digs for the evolutionary origins of humankind -- and suggests a stunning new vision of our competing ancestors.