I've learned that there is a lot of misinformation concerning average grades at Berkeley, some of it on various threads on College Confidential. As a Cal professor I have access from the administration to average cumulative grade data for all majors as well as average major grades for some.
In terms of cumulative GPAs here are some averages for the 2010-2013 period for some of the various Biology majors that pre-med and pre-health students often select:
Public Health: 3.43
The data on average "major GPAs"--i.e. the average of the upper and lower division courses within each major-- is much more difficult to obtain. Some departments don't calculate or report this information. What I can say is that between 2010 and 2013, the average major GPAs for MCB majors was 3.25, and for IB majors it was 3.11. MCB is often considered a GPA killer for pre-meds at Berkeley, but in fact, MCB grads have higher average GPAs than grads in most other Bio majors at Berkeley. The truth is that MCB majors do very well. So please do not make any decisions based on faulty data!