I just remembered about the media furore over Michael Dini, who was sued (or at least threatened with suit by a creationist group) for refusing to give letters of recommendation to students who do not accept humans arose by evolutionary mechanisms.
On his website, he gives an explanation of his decisions over whether to write a letter of recommendation or not. (I've pasted it at the bottom of this post).
This was portrayed as a conspiracy by creationists, though it's worth bearing in mind that Dini did it very openly, and explained his procedure on a public website. I personally believe that Dini gives a good justification for his actions, and his openness and honesty on the matter is admirable.
Michael Dini (http://www2.tltc.ttu.edu/dini) writes:
Before you ask me to write you a letter of recommendation for graduate or professional school in the biomedical sciences, there are several criteria that must be met. The request for a letter is best made by making an appointment to discuss the matter with me after considering these three criteria:
Criterion 1
You should have earned an "A" from me in at least one semester that you were taught by me.
Criterion 2
I should know you fairly well. Merely earning an "A" in a lower-division class that enrolls 500 students does not guarantee that I know you. In such a situation, all I would be able to provide is a very generic letter that would not be of much help in getting you into the school of your choice. You should allow me to become better acquainted with you. This can be done in several ways:
1) by meeting with me regularly during my office hours to discuss biological questions.
2) by enrolling in an Honors’ section taught by me.
3) by enrolling in my section of BIOL 4301 and serving as an undergraduate TA (enrollment is by invitation only).
4) by serving as the chairman or secretary of the Biology Advisory Committee.
Criterion 3
If you set up an appointment to discuss the writing of a letter of recommendation, I will ask you: "How do you account for the scientific origin of the human species?" If you will not give a scientific answer to this question, then you should not seek my recommendation.
Why do I ask this question? Let’s consider the situation of one wishing to enter medical school. Whereas medicine is historically rooted first in the practice of magic and later in religion, modern medicine is an endeavor that springs from the sciences, biology prominent among these. The central, unifying principle of biology is the theory of evolution, which includes both micro- and macro-evolution, and which extends to ALL species. Someone who ignores the most important theory in biology cannot expect to properly practice in a field that is now so heavily based on biology. It is easy to imagine how physicians who ignore or neglect the Darwinian aspects of medicine or the evolutionary origin of humans can make poor clinical decisions. The current crisis in antibiotic resistance may partly be the result of such decisions. For others, please read the citations below.
Good medicine, like good biology, is based on the collection and evaluation of physical evidence. So much physical evidence supports the evolution of humans from non-human ancestors that one can validly refer to the "fact" of human evolution, even if all of the details are not yet known; just as one can refer to the "fact" of gravity, even if all of the details of gravitational theory are not yet known. One can ignore this evidence only at the risk of calling into question one’s understanding of science and the scientific method. Scientists do not ignore logical conclusions based on abundant scientific evidence and experimentation because these conclusions do not conform to expectations or beliefs. Modern medicine relies heavily on the method of science. In my opinion, modern physicians do best when their practice is scientifically based.
The designated criteria for a letter of recommendation should not be misconstrued as discriminatory against anyone's personal beliefs. Rather, the goals of these requirements are to help insure that a student who wishes my recommendation uses scientific thinking to answer scientific questions.