Final answer:
In species with promiscuous mating systems, males develop secondary sexual characteristics due to sexual selection, which can increase reproductive success despite potential survival disadvantages.
Step-by-step explanation:
When analyzing the traits of males in species where females are promiscuous and mate with multiple males, we typically expect to see indirect competition among males. This kind of competition often leads to the development of elaborate secondary sexual characteristics, which arise as a result of sexual selection. Males may develop impressive traits, such as bright plumage or complex mating calls, to attract females and ensure that their genes are passed on to the next generation, despite these traits potentially decreasing their survival odds. The good genes hypothesis suggests that these impressive traits signal genetic superiority. Additionally, the handicap principle theorizes that the ability to survive with such extravagant traits indicates overall fitness, thus more attractive to potential mates.