Final answer:
The 'grandmother hypothesis' suggests an extended lifespan of older females among hominins 30,000 years ago, contributing significantly to early human societies by caring for grandchildren and aiding their own children's resource gathering.
Step-by-step explanation:
The "grandmother hypothesis" suggests that 30,000 years ago among hominins, there was an extended lifespan of older females. This hypothesis posits that older women played a crucial role in the survival and social structures of early human societies. The hypothesis contends that as women lived longer past their childbearing years, they could contribute to the group in significant ways, such as caring for grandchildren, which allowed for their own children to invest more time in further reproduction or resource gathering.