The many-hour BBC documentary Planet Earth, mentioned earlier, takes viewers way off the beaten track — deep into giant caves, for example. But humans — and human evolution — creep in.
Non-human primates are shown a dozen-odd times during the series. Only once do we see them walk erect: When baboons wade into a flooded area of Africa. This adds credence to the Aquatic Ape theory of human evolution, which assumes our ancestors came to walk upright because it helped them walk in water. David Attenborough, Planet Earth‘s narrator, made an excellent radio show about the Aquatic Ape theory.
The Aquatic Ape theory explains all sorts of physical differences between man and our closest primate ancestors — why we walk upright and they don’t, for example. My ideas about human evolution are about what happened next. I try to explain ways we differ mentally from other primates — we speak, for example. The core idea of my theory is that the human brain has changed in many ways to promote occupational specialization. For example, language — single words — began because it facilitated trade; it was the first advertising. (I think of a Guatemalan market where someone shouted “toothpaste” over and over. He was selling toothpaste.)
The magic of occupational specialization also comes up in Planet Earth. The “Planet Earth Diaries” (Making-of) section of “Seasonal Forests” describes filming baobab trees using a unique hot-air balloon designed for photography by Dany Cleyet-Marrel and piloted by him. Twice he flies into trees by mistake. “Many of Planet Earth‘s finest images would have been impossible without devoted and passionate specialists like Dany,” says Attenborough.
You might like The Hand: How Its Use Shapes the Brain, Language, and Human Culture by Frank R. Wilson for a hand-oriented view of human evolution.
Thanks. I picked it up in a bookstore but I should look at it again. Certainly the flexible hand preceded the big brain.
Interesting read. I missed the show (no TV) but saw the baboon wading video and macaque swimming video at Laelaps blog.
I agree with much of the AAT, but see it as part of life in a generalised coastal tropical habitat. Your mention of occupational specialization in later humans fits with my interpretation of butted hand axes as both butchering tools and woodcrafting tools used to construct the first dugout boats from hollow bent trees at waterside. These dugouts were the ‘first cargo pickup trucks on the aquatic superhighway” that allowed trade and settlements upstream inland in areas formerly dominated by the big cat predators, and allowed relatively safe easy transport of people including babies, with slingstone pebbles as ballast in the bottom for stability, and push-pole thrusting spears propelling and spare throwing spears bunched aside like arrows in a quiver. Further development of boats included thinner lighter dugouts and later portageable ribbed skin kayaks, birchbark canoes and plank sailboats on the sea of galilee 20,000 years ago.
The words Tectonic, Technical, Technology has the root Tek, which is Greek for carpenter or craftsman. I think it derived from the sound of stone “tick-ticking” against stone to make a hand axe and other simple tools. Other languages around the world have similar sounding words for crafting tools, which suggest great antiquity. (Chip or chop are other variations of it.)
The hand in primates (and even more in anthropoids) was selected for plucking loosely hanging fruits in angiosperm trees, which had previously been the long held domain of fruit bats and frugivorous birds. Plucking allowed the changes in the jaws and dental structure, which allowed the brain to enlarge later.
This combined with greater vertical climbing and posture produced a more stable bipedal locomotion, as seen in the gibbon and spider monkey. Bipedal wading doesn’t cause dry land bipedalism (see wetland apes which wade on 2 legs but walk on 4, while gibbons are bipedal on the ground but never wade), but it does reinforce an already bipedal habit.
Most likely the combination of fruit tree climbing, wading for molluscs in mangroves, shore cliff climbing for seabird eggs, coconut palm climbing, beachcombing for turtle eggs, vertical floating (with inflated laryngeal air sac) while plucking aquatic vegetation all combined to further the upright stance in hominoids and resulted in the complete loss of the tail. Later, the ancestors of the Great apes expanded inland along gallery forests staying arboreal and becoming more quadrupedal when on the ground, while ancient Homo erectus improved swimming and changed from vertical floating to horizontal backfloating (losing the lar. throat air sac but gaining a layer of skin fat) resulting in greater hydrodynamic linearity, thermoinsulation and oxygen breath holding abilities and becoming a more adept diver for shellfish and crustaceans.
I envision them diving as male-female pairs alternating dives, while the younger males acted as area patrol guards/gangs and younger females as babysitters at the shore. Later the use of hollow logs and driftwood as floats in waters with crocs or sharks began the emergence of the most primitive vehicular industry, shells pebbles and stone tools used to make simple dugouts.
Very interesting comment, thanks. And you have a most thought-provoking website, too.
thanks, yep.