Reproductive support by post-reproductive individuals
(specifically post-reproductive females)
likely led to the development of menopause
[8, 9]. Menopause allows older females
to shift time and energy away from their own
reproduction and towards their close kin's reproduction
[9].
• Maintenance of extensive male support of reproduction
via provisioning of both female and offspring
likely led to concealed ovulation and continuous,
nonreproductive sexual activity [10, 11].
Both traits help maintain extended male-female
relationships [3].