(RxWiki News) Whales have often held the fascination of many people, and women may have more in common with these magnificent creatures that cruise our oceans than we originally thought, particularly women in menopause.
In a study of killer whales, pilot whales and humans, researchers discovered that grandmothers have a special role in the survival of the young in their families. This likely explains why females in each of these species move into menopause rather than continuing to bear children of their own late in life.
"Menopause may be linked to social system's need for a grandmother role."
Dr. Michael Cant and researchers from the Universities of Exeter and Cambridge recognized that killer whales, pilot whales and humans are the only three known mammals where females stop breeding relatively early and adopt an active role in parenting the offspring of their own children.
It appears that this need for a grandmother role in these species is the key to why menopause has evolved in killer whales, pilot whales, and humans.
While social structures differ, in each species the older females become more genetically related to their children’s children. This relationship motivates older females to ensure the survival of her grandchildren by sharing parenting skills and resources (such as food). It also helps the family or species as a whole survive generations to come.
Dr. Rufus Johnstone, from the Department of Zoology at the University of Cambridge, and co-author of the study, said, "For the first time we can see a common link between menopausal species which provides a valid explanation as to why this trait might have evolved.”
This study adds to the already special role that grandmothers hold in their grandchildren’s lives and creates a more positive meaning to the word “menopause.”