With a solid-phase radioimmunoassay it has been possible to detect species-specific collagen and albumin in fossils as old as 1.9 million years. This technique may provide new data on the genetic relations of fossil species to each other and to living forms.
This rersearch was supported by the L.S.B. Leakey Foundation, the Wenner Gren Foundation, and the University of California, San Francisco.