A physics professor was very strict about attendance, and
despised tardiness. Every student caught arriving to class late
(especially those interrupting his lecture) was quickly
reprimanded in front of the whole class. Students were quick to
comment on the professor's genetics.
One day a student entered through the front doors of the lecture hall, while the professor was writing notes on the chalkboard. The professor caught the student out of the corner of his eye (this acute sense of peripheral vision, further supported the rumors of his evolution), and turned to face the student. He demanded, "What do you think you're doing?"
Being a science student, one naturally thinks quickly, so the
student snapped up and replied, "I came down from the back to
get a better look at the board."