As critical persons that scientists must be, we are told to question everything (and we should). And this is good, but we should also know what kind of questions we can ask in a given context. The prime example that I find (now considering myself a life scientist) , is when someone asks for the reason of something in biology: why doesn’t the virus does this? why does the cell has this protein and not other? These seem very natural questions to ask. However, if we think carefully, we are asking to be given reasons for natural phenomena. Furthermore we also must understand that reason is something that only organisms capable of understanding what reason is, and can have an ulterior motive for doing things a certain way. To the best of my knowledge we humans are the only ones in this planet that can do that. Besides, reason embodies a set of concepts and values that are inherently human, so we cannot even understand the concept that nature has of reason (if there is one).
The only answer that can be given to WHY questions in biology is the following: because it works. I do understand that sometimes we pose WHY questions and get satisfactory answers, but rather these questions are HOW questions which are the type of questions that science can answer. Nature doesn’t have a reason for doing things, there have been many possibilities and there will continue to be many possibilities that nature will try. The ones that work will be the ones that will stay.
As an example in the field I work if someone asks: WHY do bacteria become resistant? someone might want to give the following answer: “because bacteria want to survive the killing effects of antibiotics”. Which of course is a perfectly good reason if we were talking about humans, we have the capacity to not want something. Now, bacteria don’t have this self awareness and cannot decide whether they want to live or not. Their survival depends on obtaining a gene or a mutation that allows them to stay alive, simply because that mutation or gene is what it works to not be killed. I think the appropriate question here will be: HOW is it that bacteria become resistant to antibiotics? This is something that can be proved or known by using the scientific method.