The Independent on Saturday

Speaker’s corner

- James clarke

DOCTORS now agree that mom was right – eat fish because it’s good for the brain. More than that, there’s now a suggestion that early humans living along the South African coast and consequent­ly eating lots of fish were more intelligen­t than humans living inland living off meat and veggies.

And women, because they ate a great deal more shellfish than men – after all, they were the gatherers – were probably brighter than their menfolk.

Ichthyolog­ist Professor Mike Bruton, who is now a generalist dedicated to promoting science here and in the Middle East, recently gave a talk about fish and brains in Cape Town. He focused his talk on studies by a friend, archaeolog­ist Professor John Parkington, at the University of Cape Town. Parkington suggested that fish – especially shellfish because they provide an important nutrient for the brain – led to the emergence of the first really intelligen­t humans.

Parkington studied pre-historic huntergath­erer people living along the west coast, where one finds the world’s largest middens of discarded shells. He is researchin­g a period of time that began before humans migrated from Africa.

Bruton says big-brained humans took a different route in evolution to that of other large mammals. Interpreti­ng Parkington, he described how the human species “invested in the process of developing a large brain and skull to contain it”.

As an animal’s body gets bigger, the brain gets bigger, though not at the same rate. A large but not terribly bright mammal, like a rhino, typically has a brain about 0.4% of the body weight.

Humans broke the rule by having a large body and a large brain – about 2% of our body weight. Our coastal ancestors had access to a high quality food to feed their brains – fish.

Brain developmen­t is driven by what a pregnant mother eats while she is breastfeed­ing her baby. And the key nutrients needed are polyunsatu­rated fatty acids (PUFAs) without which “children are irremediab­ly mentally and visually disadvanta­ged”.

PUFAs are uncommon in the meat of terrestria­l animals such as antelope, but very common in marine and freshwater fish and shellfish. Bruton says coastal women habitually gathered and ate large amounts of shellfish while men wasted their time and energy hunting down sirloins and chops that provided few nutrients for brain developmen­t.

Seafood allowed Homo erectus (the species that preceded Homo sapiens) to accelerate brain developmen­t, so infusing the human race with a greater intelligen­ce allowing them to eventually become rocket scientists, lawyers, doctors and computer programmer­s, and their children to send SMS messages to each other simply by using their thumbs.

It seems to be no coincidenc­e that the world’s earliest signs of humans engaging in creative activities – making decorative necklaces, water vessels and advanced stone artefacts – are along the Cape coast.

So it wasn’t simply shambling beetlebrow­ed humans that eventually migrated from Africa – it was intelligen­t humans.

Parkington, during a lecture, once held aloft an apple and perlemoen shell and said: “Homo sapiens (meaning ‘man the wise’) probably came about not in some Middle East orchard, but on a Cape beach.”

Gonzales, the fishmonger, would agree with all this. A customer who marvelled at how quick-witted and intelligen­t Gonzales was asked him: “What makes you so clever, Mr Gonzales?” Gonzales said, “Fish heads. Eat enough and you’ll be positively brilliant. Only R150 a kilo.” The customer bought some.

A week later, he complained they were disgusting and he didn’t feel any smarter. “You didn’t eat enough,” said Gonzales. The customer went home with 20 more. Two weeks later he was back – and angry. “Hey, Gonzales,” he said, “you’re selling me fish heads for R150 a kilo when I can buy the whole fish for that. You’re ripping me off !” “You see?” said Gonzales. “You’re smarter already!”

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