I have problems with the logic or structure of this part: 
"we look at evolution ... by scientifically understanding ... and how we currently call this process illness and dis-ease "
*Evolution is not equal to disease, but the process of evolution might include disease
*We look by understanding? Rather the other way around, one understands by looking?
*The whole sentence is very long and hard to directly get it's meaning.

Yet, there are proposals that provide a clearer "how" in only one sentence. What could be appropriate, taking shortness and clarity into account?