Female marmosets that remain in their natal groups and help their mothers to carry new infants instead of dispersing and reproducing themselves:

Question

Quizplus · Accepted Answer

Female marmosets that help their mothers carry new infants instead of dispersing and reproducing themselves may benefit their inclusive fitness. This means that, by helping their relatives (in this case, their siblings), they can improve the survival and reproductive success of their kin, which shares their genetic material. While this behavior may not increase their own direct reproductive success, it can still promote the transmission of their genes to future generations through their relatives. This is a form of indirect fitness, which can contribute to an individual's overall evolutionary success. Therefore, these female marmosets are behaving in a way that makes evolutionary sense, despite not reproducing themselves.

Female Marmosets That Remain in Their Natal Groups and Help