Final answer:
Male redbacks exhibit self-sacrifice as an adaptive behavior to increase offspring survival, an example of altruistic behavior that raises the chances of their genes being passed on.
Step-by-step explanation:
Self-sacrifice in the male redback spider is indeed an example of adaptive behavior related to sexual selection. Male redbacks will sometimes sacrifice themselves to the female during mating, which increases the survival rate of the offspring. This behavior can be explained by the paternal investment hypothesis, which suggests that the male's self-sacrifice enhances the chances of his genes being passed on. Although it may seem counterintuitive, this behavior is ultimately altruistic, and it is about increasing genetic fitness rather than minimizing the male's risk of predation or facilitating mate bonding.
According to the good genes hypothesis, females choose males with impressive traits, such as the willingness to self-sacrifice, because these traits indicate genetic superiority that can be passed on to offspring. Long-term parental care and the quality of offspring are another consideration. Species that provide extensive parental care tend to have fewer offspring, which means the survival of each one is critically important, and behaviors that enhance offspring survival are highly selected for.