If an organism is complex it maybe able to do more things, but it is susceptible to more things. if an organism is less complicated it may not be able to adapt well, but if it's environment changes it wont effect it that much.

The Complexity of Organisms

As we begin to investigate living organisms, we start with the simplest: Bacteria. As unicellular organisms, they seem quite simple, yet are soooooo adaptable! It's worth thinking about, and responding to: how does the simplicity and/or complexity of an organism benefit its adaptability? Include real-world examples to support your claim, and feel free to comment on each other's claims (tactfully, of course).

sarah berkowitz:

I would describe science as the study of everything in the universe, on Earth and in our atmosphere, dead or alive, water and land. This definition has expanded in my mind beyond not only the study of how things but why they work or don't work. Also, science is more than experiments, it is physically everything.