One of the most profound mysteries in the world, love between males and females, is explored. What was the evolutionary impetus which gave rise to love? Through an experiment involving the chlamydomonas, we recreate the fateful moment 25 billion years ago when genders first appeared.

Originally released by Film Ideas, 2013. Streaming video file encoded with permission for digital streaming by Infobase on March 15, 2019.

Komodo Dragon (6:22); --Origins of Sex (4:29); -- Sexual Reproduction and Species Survival (2:57); -- Fiddler Crab Courtship (4:33); -- Okinawa-benihaze Reproduction (4:05); -- Asexual Reproduction (2:11); -- Internal Fertilization (2:23); -- Shelled Eggs (3:04); -- Incubation Strategies (3:42); -- Raising Marsupial Young (1:38); -- Primate Society and Courtship (7:28); -- Credits: Mating: The Search for the Other Half (0:49); .