I think that statistically, philosophy is the major with the highest rate of med school acceptance, but take into account the number of people applying to med school from each major, biology only has an abysmal acceptance rate because everyone applies, one of the things that pissed me off about college, drunk idiots who think that they can get into med school because they're bio majors. Anyway, as long as you are at the top of your program, it should not matter which major you do, a bio major doesn't hurt you.