Due to an odd quirk of genetics and some unique evolutionary circumstances, two humans who lived at different times in the distant past managed to pass on a very small fraction of their genomes to you. And to me. To all of us.

Originally released by Knowledgemotion, 2018. Streaming video file encoded with permission for digital streaming by Infobase on February 21, 2020.

The Two People We're All Related To (9:31); .