Arguably genetics did not exist, certainly as a science, before Darwin's original evolutionary theories were published. Mendel was only starting to publish his work at the time, so while animal husbandry and
ad hoc agricultural genetics were in existence there was nothing that we would consider comparable to modern genetics and certainly nothing like molecular genetics.
Obviously the modern synthesis of evolution could not precede Mendelian genetics.
I'm a bit worried about your Medical Science angle Schraf, I would say it is pretty arguable that a large amount of medical science is simply based on first hand observation of human anatomy and trial and error discovery of successful new treatments.