A Ph.D in most biological sciences would only teach you enough to get through the first year of medical school (although in far more detail than you need for me

A Ph.D in most biological sciences would only teach you enough to get through the first year of medical school (although in far more detail than you need for medicine). The last 2 years of medical school are a practical application of your coursework as you work with residents and more senior doctors to diagnose and treat patients. Medical school still follows the old guild model where you do some initial learning and then a long period of apprenticeship before you are allowed to go off on your own. That's why combined PhD/MD programs still take about 7 years - and that's not including residency and fellowships if you decide to actually practice medicine instead of becoming a scientist. disclaimer - not a doctor, but did a biological PhD and have several family members who just completed their MDs.