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Sunday, June 15, 2014

Chimpanzee Fathers

It's father's day, and in the news there is an item about the genetic contribution of chimpanzee fathers to the evolution of the species.

Ninety percent of genetic mutations in chimpanzees come from the father, and the older the father, the more mutations. Bow is still quite young, so I expect he would be a source of fewer mutations than most, were he allowed to father a child this year.

Bow in the outer pen yesterday

When I think of that, it reminds me of those people who say that we cannot safely interact with chimpanzees because they have not undergone a long process of domestication. By domestication, they do not mean becoming personally accustomed to living in a house, as the etymology of that word would imply. They mean a selective breeding program. Those people are crypto-eugenicists.

If we believed what they were saying and wanted to follow their train of thought to its ultimate conclusion, the obvious solution to the "chimpanzee problem" would be a breeding program designed to bring out more cooperative traits, less violence and higher intelligence. The product of that breeding program would be "domesticated chimpanzees", as safe to own as dog or cow.

I don't think it actually works that way. The truth is that nurture has a huge impact on how anyone turns out. The sense of having a common interest with others, as opposed to a conflict of interest, also makes a huge difference. Bow knows that we are in this together. Another chimpanzee who does not know me would behave completely differently toward me.The same is true for dogs. You cannot know that a dog is safe to interact with unless you know the dog. 

Maybe this idea that behavior is pre-wired in higher functioning mammals is influenced by the study of insects. Insects seem to pretty much know what they are supposed to be doing without anyone ever having told them. Yesterday, the bees on my property gravitated toward the blackberry blossoms.

The butterflies, on the other hand, congregated by the purple milkweed flowers.

How did they all know what they were supposed to be doing? And what made them all decide not to show up this morning, just because it looks like rain again?

Many things that Bow and I do also come pre-wired. The way we stand, for instance.

The way we move, the things we like to eat, the sorts of thoughts we have, all do involves some genetic predisposition. But who our friends are, who we rely on in a pinch and who is a stranger to us is something that depends on our experiences.

Chimpanzee fathers may cause ninety percent of the mutations, but it's the person the chimpanzee grows up with who is ultimately the trusted family member. 


  1. I thought the scientific info about how if Bow had a child now it would have far genetic mutations than older chimpanzee father was quite similar to humans. People always think an older woman having a baby is the cause of a child having certain mutations, but men can have the same issues. My aunt had her daughter when she was 43, and her daughter did not have any issues. Of course I realize having a child when you are older does up the chances of the genetic mutations issues, but I thought maybe it would be interesting for you to write more about how chimpanzees and humans are similar on this front, which might open understanding to people who simply view chimps as exotic creatures, rather than having many similarities to ourselves.

    Also, I love the photo of the purple milkweed flowers, which look far more verdant than the ones I spotted on a nature walk here in Southern California.

    1. Hi, Julia, yes it is true that in humans, too, there are more chances of mutation from an older father than an older mother, because women have all their eggs at birth, whereas men have to produce sperm over time. The article pointed out that in the case of male chimpanzees, they have to produce more sperm over a lifetime because of the way their competition over mates works, so the chance of genetic mutation from older males is higher even than in humans. This also presumably would speed up their evolution while slowing ours down, assuming any of those mutations were positive ones.

      One of the things that monogamy in many human societies has caused is a decline in competition over mates, as seen from the male perspective. This is not necessarily a good thing for human females, despite what many people want us to think.

      Thanks for noticing the photo of the milkweed flowers; I am appreciating the beauty of our milkweed more and more each day.