Was thinking about "logic" in biology while reading Nick Lane's book "Power, Sex, Suicide" (ignore the catchy title; it's a great book). Not every logic applied by someone who studies nature is automatically bio-logic. In summary and retrospect, I would say that most of the logic I have used in my years in biology was math, physics, or engineering logic. Very little was truly bio-logic. Nick Lane, by contrast, argues very logically that bacterial design prevented them from growing and evolving the complexity of the higher organisms that surround us today. What I am trying to say is this: determine and address the root question (challenge) in what you do as early and as rigorously as possible.