Why complex life needs ENDOSYMBIOSIS

WITH EVOLUTIONARY BIOLOGIST JV CHAMARY

You’ve probably heard of symbiosis (Greek for ‘living together’), a close and long-term association between two different organisms. Endosymbiosis occurs when one organism, known as the endosymbiont, lives inside another, the host. Generally, endosymbionts are small enough to reside within host cells but they aren’t parasites. The interaction between any two species can range from parasitism – where one organism exploits a (usually larger) one to the point of being harmful – to mutualism, in which the association is beneficial to both partners. Unlike parasitic associations, endosymbiotic relationships typically aren’t one-sided.

How do the hosts benefit?