Question

In primates, males are often larger than females. If sexual dimorphism evolved to enable males to compete for access to multiple females, in which mating system would we expect to see the greatest sexual dimorphism?

• A. Monogamy
• B. Polygyny
• C. Polyandry
• D. Parthenogamy

Hint:

In species with polygyny, males often exhibit greater sexual dimorphism due to the competition for mates. Look for larger body size, more developed secondary sexual traits, and other displays that increase male reproductive success.

Answer 1

The Correct Option is B

Sexual dimorphism refers to the physical differences between males and females of a species. In species with polygyny, where one male mates with multiple females, males often compete with each other for access to mates. This competition can lead to the development of larger body size, more pronounced physical features such as larger canines or more colorful displays, which are favored by females when selecting mates.

In contrast, in monogamous systems, where one male mates with one female, the competition between males is generally less intense, as there are fewer males vying for the same female. Therefore, sexual dimorphism is typically less pronounced in monogamous species.

In polyandry, where a female mates with multiple males, sexual dimorphism is often weaker because there is less male-male competition for access to females. Similarly, in parthenogamy, where reproduction occurs without fertilization, sexual dimorphism does not develop in the same way.

Conclusion:
Therefore, polygyny, where one male mates with multiple females, tends to result in the greatest sexual dimorphism due to the increased competition and selection pressures on males to display traits that enhance their chances of reproductive success.