Sixth-Sense Filters at Work

- a typical instance -

Here is a page showing a modern natural scientist’s sixth sense generating sets of images devoid of sight-sound-touch-smell-taste verifaction, with notice of the highly trained local cultural filtration requisite to each. The discourse concerns the phylogeny of primates:

My imagination finds high-speed brachiation more exciting even than flying, and I like to dream of my ancestors enjoying what surely must have been one of the great experiences life could offer. Unfortunately, current thinking doubts that our ancestry ever went through a fully gibbon-like stage, but it is reasonable to conjecture that Concestor 4, approximately our 1-million-greats grandparent, was a small tree-dwelling ape with at least some proficiency in brachiation.

Among the apes, gibbons are second only to humans in the difficult art of walking upright. Using its hands only to steady itself, a gibbon will use bipedal walking to travel along the length of a branch, whereas it uses brachiation to travel across from branch to branch. If Concestor 4 practiced the same art and passed it on to its gibbon descendants, could some vestige of the skill have persisted in the brain of its human descendants too, waiting to resurface again in Africa? That is no more than a pleasing speculation, but it is true that apes in general have a tendency to walk bipedally from time to time. We can also only speculate on whether Concestor 4 shared the vocal virtuosity of its gibbon descendants, and whether this might have presaged the unique versatility of the human voice, in speech and in music. Then again, gibbons are faithfully monogamous, unlike the great apes which are our closer relatives. Unlike, indeed, the majority of human cultures, in which custom and in several cases religion encourages (or at least allows) polygyny. We do not know whether Concestor 4 resembled its gibbon descendants, or its great ape descendants in this respect.
Let’s summarise what we can guess about Concestor 4, making the usual weak assumption that it had a good number of the features shared by all its descendants, which means all the apes including us. It was probably more dedicated to life in the trees than Concestor 3, and smaller. If, as I suspect, it hung and swung by its arms, its arms were probably not so extremely specialised for brachiation as those of modern gibbons, and not so long. It probably had a gibbon-like face, with a short snout. It didn’t have a tail. Or, to be more precise, its tail vertebrae were, as in all the apes, joined together in a short internal tail, the coccyx... .

- Richard Dawkins, The Ancestor’s Tale
(2004), pp 121-2