TED-ED: How we think complex cells evolved - Adam Jacobson

Imagine you swallowed a small bird and suddenly gained the ability to fly - or you ate a cobra and were able to spit poisonous venom! Well, throughout the history of life (and specifically during the evolution of complex eukaryotic cells) things like this happened all the time. Adam Jacobson explains endosymbiosis, a type of symbiosis in which one symbiotic organism lives inside another.