By Les Minter
Pliny the Elder (ad 23-79) famously remarked that there was “Always something new out of Africa”, and it turns out that his own species, Homo sapiens, is a great example.
The African origin of “anatomically modern” humans, between 200 and 100 ka (thousand years ago), is now supported by both fossil and genetic evidence.
The most significant feature of modern humans is our large brain, 3 – 4 times larger than would be expected in a mammal of our size and requiring 20% of our metabolic energy to maintain (up to 60% in the new-born).
A study by Simon Neubauer in 2018 found that the increase in brain size took place
about 300 ka but its characteristic globular shape only started to form 130 ka, reaching its present shape between 100 and 35 ka.
Fossilised skulls enable us to track changes in the shape and size of the brain,
but language, culture and other cognitive abilities do not fossilize and must be inferred, using archaeological evidence, such as, for example, tools or other artefacts, the use of fire (eg. hearths), or symbolic marks scratched on fragments of shell, bone, ochre, etc.
Recent evidence suggests that complex cognition may have appeared between about 164 and 75 ka (Marean, 2010).
By the way, in case you were wondering about the connection between golf and human cognition, it’s not that golf represents the pinnacle of human achievement: on the contrary, the use of clubs and the wild dancing associated with an activity known as “clubbing” appear quite early in the development of anatomically modern man.
The connection occurred when a survey was carried out near Mossel Bay in 1997, to assess the possible impact on the environment, of a proposed golf course development, perched on the clifftops at Pinnacle Point, overlooking the sea.
During the survey, 28 archaeological sites were discovered, 15 of which were caves or rock shelters that had been occupied by people (Strandlopers) foraging for food along the coast. Archaeological excavations began in July 2000.
Pinnacle Point Golf Course complex was opened in 2006 and has repeatedly been judged the Best Golf Course in South Africa and among the Top Ten most beautiful in the world.
Pinnacle Point Cave represents a “snapshot of human occupation from ~ 162 to 90 ka” (Marean 2010), broadly overlapping the period when early humans began to make even better use of their large brains.
It is one of three sites collectively known as The Cradle of Human Culture, and moves are afoot to have it registered as a World Heritage Site.
Along our coastline there are more than 1000 shell middens: piles of shells left by our human ancestors who foraged for mussels, limpets, alikreukel, or anything edible washed up on the beach.
In his remarkably interesting and beautifully illustrated book: Shorelines, Strandlopers and Shell Middens, (2006), archaeologist John Parkington expresses the view that “it was the regular consumption of shellfish and other seafood that allowed us the luxury of such a large brain” (see also Crawford et al. 1999 and Kyriakou et al., 2016).
How so?
Long-chain omega-3 fatty acids such as DHA (docosahexaenoic acid) are important components of cell membranes and essential for the normal development and function of our brain and eyes.
They enable brain cells to communicate with one another and are needed in large quantities while the brain is developing during late pregnancy and the first 18 months after birth. Animals cannot produce DHA from scratch but obtain it from plants.
Microscopic marine plants (phytoplankton) pass it down the food chain where it accumulates in the fatty tissues of fish like mackerel, cod, and salmon, as well as filter feeders such as oysters and mussels, providing a rich, indirect source to the animals that feed on them.
Brown mussels, alikreukel, limpets, chitons and black mussels were the most common seafood species collected by the occupants of Pinnacle Point cave.
Xo is sitting in a small rocky cove just around the corner from the cave, flaking a nice round quartz cobble core. He grips the core firmly in his left hand, using his fingers and opposable thumb to good effect and brings the hammerstone down, removing a sharp-edged flake.
Back in the future, Joe, who worked as a New York janitor before becoming a professional golfer, is on the green of the 8th hole. He addresses the ball somewhat colourfully, having just lost one over the cliff on the approach.
He carefully arranges his opposable thumbs and other digits around the SuperStroke Triaxon Pistol GT Tour putter grip (favoured by Rory McIlroy) before coaxing the ball …. into the hole.
Progenitor and Pro janitor, separated by 100 000 years! Food for thought?
*Les Minter is a retired herpetologist and is therefore someone with friends in low places.
References:
Crawford 1999 Lipids 1999
Kyriacou et al. 2016 Journal of Human Evolution 97: 86-96
Marean et al. 2004 PaleoAnthropology 2: 14-83
Marean 2010 Journal of Human Evolution 59 Sep-Oct 425-443
Neubauer et al. 2018 Sci Adv.
Parkington 2006 Shorelines, Strandlopers and Shell Middens