<p>Mini, from what I have been piecing together, you would see a significant drop in the % of students going directly to med school at a lot of colleges of different types and different selectivities.
When I was a first year medical student the average age was 23-24, it is now a little over 25. Many students are spreading their science courses out over the whole 4 years (this is what admissions folks at various LACs told us) to improve their GPA, others are adding a 5th year of research to pad their resumes. There are a number of post-bac programs that didn’t exist 25 years ago, yada, yada. At some point (just like college admissions and ECs or SAT prep) the process takes on a life of its own - if a quarter of the applicants have done a year of research, or have a higher GPA, then you need to do something like that to improve your chances,</p>