"Studies of simpler and more stable systems make it easier to observe patterns that may influence the way we think about more complex systems."

If you were ever curious about how certain bacteria survived the Cretaceous-Paleogene global extinction (extinction of the dinosaurs) read the following:
Astrobiology, vol. 9, Number 6, 2009, Harriet Jones, et al., Experiments on Mixotrophic Protists and Catastrophic Darkness.
In this paper several experiments were done to test the effect that 6 months of darkness and exposure to controlled amounts of DOC would do to mixotrophic bacteria. Turns out, they eat each other's dead bodies in order to survive. I am trying to imagine what a human would do if it was locked up with controlled nutrients with 1000's of other humans in the dark for 6 months... and I'm thinking "Zombies"? I guess we are not too far from the root of the tree, huh?