What Grandmas Are For

I’m currently reading William H. Calvin’s A Brief History of the Mind. Calvin writes really well, and puts together an absorbing and convincing story of how the human mind has developed. While he traces the development of the human species, starting about 7 million years ago when hominids shared a common ancestor with chimpanzees and bonobos, it appears that the evidence for the modern mind only appears as little as 50,000 years ago. And that’s even though Homo sapiens has been around for at least 100,000 years.
So something caused (in Calvin’s phrase) "the mind’s big bang" to occur around 50,000 years ago. He posits a number of candidates for the trigger, for example, the use of the structured planning that is necessary to throw things accurately being applied in other modalities and time scales. He also argues that "if children are exposed to structured stuff can softwire their brains to better handle it, and if the younger they are exposed, the better they do as adults, then the more precocious children will soon double the amount of structured speech heard by the next generation of youngsters… So the transition might be language, acting like a contagious disease over a few generations’ time."
This is EvoDevo, when evolution interacts with the development via the einviroment. Today, I ran across an interesting article in Seed magazine: Why Do Grandmas Exist? This points out that the menopause is something that is unique to the female Homo sapiens – none of the other primates have this. Other primate females are capable of becoming pregnant until they die. So the menopause might also be one of the triggers of the big bang: females who are no longer capable of child bearing have more time to babysit or to forage for food. And the babysitting might help the children be "exposed to structured stuff".
Food for thought.

About Geoff Coupe

I'm a British citizen, although I have lived and worked in the Netherlands since 1983. I came here on a three year assignment, but fell in love with the country, and one Dutchman in particular, and so have stayed here ever since. On the 13th December 2006 I also became a Dutch citizen.
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2 Responses to What Grandmas Are For

  1. Gelert says:

    Coming here always sends me off on your links and further reading on the fascinating topics you put up. This is another one. I love the idea of a mental big bang in human beings. Something happened. You deserve more readers – so many people would enjoy coming to read you.

  2. Geoff says:

    Hi, Gelert, thanks for the compliment. But really, it’s just intriguing – thinking about these things. There was something else I was going to say when I started this reply to your comment, but it’s fled my consciousness. Bugger. I’m sure it was really profound, but I’ve had the equivalent of a visit from the person from Porlock… Oh well, you’ll just have to wait for my comments on Mary Roach’s Stiff…

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