Man as the Prayer: The Origin and Nature of Humankind by Yup Lee
Chapter Two: The Meaning of Red Ochre
Anybody is free to imagine whatever he wants. Why, of all things, did I fantasize two apes copulating? Why on earth did I imagine that an ape examined the perineum of another, and poked it with a digit to sniff? The reason is that such a behavior has a direct bearing on the evolution of the human species from apelike creatures.
Sexual behavior is, in truth, not the last, but the first thing to consider for a proper understanding of human evolution. It seems that one of the main reasons why anthropologists have trouble explaining human evolution neatly and properly is that they have not grasped the essence of the sexual customs and practices of our distant ancestors and their repercussions on human evolution. Seemingly indecent behaviors of the ape actually conceal important clues to those customs and practices.
Keeping in mind the possibility that such behaviors may have had indelible effects upon human culture and history, let me begin my explanation by discussing the nose.
In general, animals living on the ground have very sensitive noses because they rely primarily on their sense of smell to investigate their surroundings.1 For their survival and reproduction, they make use of various kinds of odors which permeate the air by spreading low on the ground.2 But, for animals living high up in the trees, a three-dimensional space, the story may be quite different. In fact, the senses of vision and touch are highly developed among primate animals, especially among higher primates, while the sense of olfaction is markedly degenerated.3
It is speculated by G. Elliot Smith that, for arboreal primates, the eyes were more important for survival than the nose; therefore, some of the function of the nose was yielded in favor of the eyes.4
As a consequence of such change, the eyes, which had been on both sides of the face, moved to the front, making it possible for their owners to view things in three dimensions by bringing them to focus. In addition to the acquisition of stereoscopic vision, they ultimately came to acquire color vision thanks to the evolutionary force of what is called natural selection. As the sense of vision developed, the function of hands developed in tandem, sharpening the sense of touch.
Animals which dwell on the ground investigate any objects they come across by sniffing at it first with their long snouts, and investigate further by biting and tasting them with their teeth and tongues. In contrast, primates that have adapted to the tree life examine any objects first with their eyes to see and then with their fingers to touch, a phenomenon which may have stimulated the development of intelligence. This kind of explanation which attributes some of the most salient features of primates to their arboreal life has been widely accepted.5
In contrast, an alternative hypothesis explains that ancestral primates earned their keep by taking small insects as prey in their habitats with the result that their eyes and extremities became more and more specialized with the passage of time.6
For whatever reason, the eyes of primates were highly developed over tens of millions of years while their noses degraded substantially. Nonetheless, the nose seems to have played a decisive role among our own ancestors at critical moments, but not for day-to-day survival.
Anyway, what the leading animal in imagination did just before mating is actually fundamental for the reproduction and preservation of the species involved. To ensure its own reproductive success, it had no choice but to mobilize sense organs such as the eyes, hands and nose. It is not uncommon, among mammals, for males to investigate the female genitals with their noses, mouths, forefeet, and/or hands as a part of precopulatory play.7
In fact, our ancestors did almost the same thing in the past for millions of years, and to them we owe the preservation of our own lineage. If our ancestors had not done that, all of us might not be here now.
Why was such a thing done by a male ape which lived about five million years ago? It is speculated that he did it to verify the ovulation of his mate. Whether he was capable of pinpointing the most fertile point is uncertain, but the ability to time copulation in relation to the occurrence of ovulation should have been under the strong pressure of natural selection because such ability increases fitness or reproductive success of the males concerned.
The majority of vertebrates mate only during a brief period of the year. Marked morphological changes take place among many of them with the arrival of the mating season.8 This is the case with many primate species of which mature females go through morphological changes during the time of sexual receptivity. One of such changes which is widespread among lower primates or prosimians is a slight swelling and/or reddening of the vulva. A much more conspicuous change known as sexual swellings shows up periodically in the skin surrounding the female genitalia among many species of Old World monkeys, as well as some of the great apes.9
Among mature females of those monkeys and great apes, the genital region swells up and its color changes when they are in heat.10 In some species of monkeys, the color of other female body parts like the chest changes, visually signaling female readiness to mate.11
In the case of the common chimpanzees, one of the closest living relatives of humans, sexual swellings are very prominent and they mate most frequently at their height.12 The labia swell a little at the age of 7½ to 8½ years, and then their anogenital parts swell up fully when they reach the age of 10 to 11 years, accompanied by the menarche after an interval of 1 to 6 months.13 The menstrual cycle of common chimpanzees is about 36 days14 and can be divided into four phases: about 6 days of gradual swelling of the perineum, around 10 days for its full inflation, 5 to 6 days of its deflation, and about 14 days of its flatness.15 (more)
Copyright © 2000 Yup Lee. All rights reserved.