" usually upperclassmen have an advantage here;"
-All it took D. to get an internship at Med. Research lab at her in-state public was an email person in charge and a short inerview where the main topic of discussion was her Music Minor. The point is that this type of opportunity almost impossilbe to obtain outside of your UG, but any UG where you attend will have them. Just do not walk by, grab the opportunity, it is up to you. D’s research was great, lasted for 3 years (she was not an upperclssmen, she just started a sophomore year), she got 2 grants, based on her own proposal (another great opportunity to write your own proposal with cost calcs.) and had a poster presentation at the end. Great LOR from person in charge, overall great experience. Nobody does research to just pad some application. The adcoms can tell the difference. And D’s college did not even have a Med. School.
Opportunities for research are absolutely everywhere. They are meanningful, rewarding and end result may be more than one expected. All around my D. were nominated for PBK by the head of the lab (as one fringe benefit).