Estrus swelling only occurs __________.
a. in females
b. when a female is ovulating
c. in the presence of males
d. in monkeys and prosimians, but not in apes
Question 2
Sexual swellings in female primates are likely to have evolved as __________.
a. a result of sexual selection
b. a means of communicating a lack of willingness to mate
c. as a means of inciting males to compete
d. a means of warding off unfit males