If the class average is too low, do profs usually curve or adjust the grading scale? My prof for my first year anthropology class is new, and I'm having trouble understanding her marking scheme. 

Here is the distribution of our class grades:


Exam 1: Median 62%, Top 75% got above 47%, while 25% got above 69%
Exam 2: Median 58%, Top 75% got above 44%, while 25% got above 70%.


We haven't gotten our final exam marks back yet, but I was wondering if this is normal for a first year anthropology course?
When it comes to grading, there really is nothing that can be considered "normal." As for adjusting grades, the answer is a definite maybe. It really depends on the instructor. I do, but many of my colleagues don't, but then they give tests with much higher averages than I do.

Exam grades and difficulties can vary from course to course and from year to year within a course, let alone between departments and institutions. There will generally be an attempt to bring grades in line with "expectations" and requirements of the school. But what those expectations are can vary widely. For instance, at one university I worked for, there was nothing wrong if a third of the students or more failed; at my current institution, it would create major headaches if so many students failed.