Toothed whales and the grandmother hypothesis

I have just returned from Vancouver visiting family out there.

Each time we go, my husband manages to fit in a trip to go whale watching. He always talks enthusiastically about the huge pods of orca he has seen (I would love to go, but don’t as I get terribly sea- sick!).

My daughter who lives out in Canada then told me about scientists at the University of Exeter that have done research looking at Orca and their family pods. The pods tend to be led by a grandmother who can be an extraordinary age, who may not have had calves herself for 40 years.

Orcas tend to live in the family pod into which they were born and both the sons and daughters stay in that pod.

The older matriarchs help their daughters and sons to find food and catch it. These grandmothers have the experience and wisdom at knowing where food supplies are and this knowledge is particularly useful at times of food shortage.  The hotspots of salmon change each year and just like fishermen, the older orca know just where they are.

It is thought that orcas go through menopause so that they don’t keep producing young which would have to compete for food with the off spring of their daughters. They can also help find food for their own sons, so that the sons are fit and can reproduce with other pods. This makes her genetically linked to her whole pod and spreads her genes with other pods too. This supports a theory called the ‘grandmother hypothesis’.

But it is not just humans and orca that go through the menopause, scientists think that only three other animals go through the menopause; narwhals, short-finned pilot whales and belugas!

What about elephant, you might ask?

Elephants are long lived and tend to live in matriarchal groups, the older elephants providing knowledge to the young on food, water and danger. However, elephants sons tend to leave the family group, which means that the matriarchs genes tend to become less related genetically to the family group over time, so it is more of an advantage for them to keep producing young through their life span (National Geographic)

My daughter and I then got into conversation about the role of grandmothers in human society. She told me about a new book called The Slow Moon Climbs from Susan Mattern which highlights menopause in humans in a positive light. The book is about the history, science and meaning of menopause and look at how our species has evolved and thrived. The book looks at the role of post-reproductive women in the hunter-gatherer period of our history where the older women would lead their clans in the gathering of food and knowledge.

This Friday, the 18^th of October is World Menopause Day.

If you would like to know more about the menopause, hormonal change, the relationship of these hormones to symptoms and the role of stress, relaxation, exercise and diet in menopause then we have a gift for you.

We have a USB stick loaded with six lectures packed with loads of useful information about the menopause that is only available from us here at Quay Physio. To celebrate World Menopause Day, we are offering The Change for £69.00 (normal price £99.00), so pop in and pick up your copy now.

Have a great week

Wendy xx

originally posted 23rd October 2019