The fundamental principle about doing science has changed. It has come from becoming a true scientist(born with natural curiosity towards natures, physics, understanding and exploring fundamentals principles of physics, life and matter) to bread butter scientist where you are pigeon holed into a cubicle writing grants all day and tinkering a very narrow part of a huge field to collect as much data possible so that you can put it in your next grant proposal. Oh by the way, do not forget to teach undergrad, grade their papers and sprinkle some tenure pressure, department politics into it and your life as a scientist is complete.