Library of Excerpts

Female Sexual Selection: Part 1

This page contains a collection of excerpts from sources used to support Shift Theory, an alternative theory of human evolution. Click here for an introduction to this new and unique theory of evolution.

"Or should we perhaps compare the whale's brain to the peacock's tail, a scintilating mental display organ for the purpose of attracting a mate and enhancing the pleasures of courtship: the whale who provides the most stimulating entertainment having the best choice of mates?" (Lovelock, J (1979) Gaia, A New Look at Life on Earth. Oxford Univ. Press: Oxford. p. 141)

"Contemporary human foraging groups obtain at least 30% of their dietary energy from animals foods, compared to 5-7% in chimpanzees. Adaptation to this calorically dense, easy to digest diet is evident in our gut morphology, as humans have a relatively reduced digestive tract in comparison to most other primates (Sussman, 1987; Chivers and Hladik, 1980; Milton, 1987). This distinct diet appears to be linked to the high metabolic costs of the human brain. In general, primate brain size varies as a direct (linear) function of body metabolism. This means that the proportion of metabolic energy spent on the brain is relatively constant across primates of all size (about 8-9% of RMR). Species spending a larger proportion of RMR on their brain have a higher quality diet than expected for their body size. Conversely, small brains relative to metabolic turnover are associated with poor quality diets. Humans represent the positive extreme, having both a very high quality diet and a brain that accounts for 20-25% of resting metabolic energy. Other researchers have previously noted the apparent link between metabolic rate and brain size. (Armstrong, 1985; Mink et al., 1981; Martin, 1989, 1990). In particular, Martin (1989) has argued that this relationship reflects the association between brain growth and maternal metabolism. This hypothesis posits that since the majority of brain growth in humans and other primates occurs prenatally and early in the postnatal period, it is maternal metabolic output (through pregnancy and lactation) that largely determines achieved adult brain size. If this hypothesis is correct, the results of the present study would imply that improvement in the stablity and quality of maternal nutrition (to support the high metabolic demands of pregnancy and lactation) was a consequence of the selection for larger brain size in hominid evolution." (Jolly, Clifford J. (1963) A suggested case of evolution by sexual selection in primates. Man (London) 63: 84-5)

“Testosterone-dependent secondary sexual characteristics in males may signal immunological competence and are sexually selected for in several species. In humans, oestrogen-dependent characteristics of the female body correlate with health and reproductive fitness and are found attractive. Enhancing the sexual dimorphism of human faces should raise attractiveness by enhancing sex-hormone-related cues to youth and fertility in females, and to dominance and immunocompetence in males. Here we report the results of asking subjects to choose the most attractive faces from continua that enhanced or diminished differences between the average shape of female and male faces. As predicted, subjects preferred feminized to average shapes of a female face. This preference applied across UK and Japanese populations but was stronger for within-population judgements, which indicates that attractiveness cues are learned. Subjects preferred feminized to average or masculinized shapes of a male face. Enhancing masculine facial characteristics increased both perceived dominance and negative attributions (for example, coldness or dishonesty) relevant to relationships and paternal investment. These results indicate a selection pressure that limits sexual dimorphism and encourages neoteny in humans.” (Perrett DI, Lee KJ, Penton-Voak I, Rowland D, Yoshikawa S, Burt DM, Henzi SP, Castles DL, Akamatsu S (1998) Effects of sexual dimorphism on facial attractiveness. Nature 94 (6696): 884-7)

“All combinations of male tactics from rape (Shields and Shields 1983, Thornhill and Thornhill 1983) to high investment (Trivers 1972) and the environmental and social circumstances that occasion their expression have recieved analysis in the literature. As Hrdy (1981) observed: “The sociobiological literature stresses the travails of males--their quest for different females, the burdens of intrasexual competition, the entire biological infrastructure for the double standard. No doubt this perspective has led to insights concerning male sexuality. But it has also effectively blocked progress toward understanding female sexuality--defined here as the readiness of a female to engage in sexual activity.” (Robert L. Smith (1984) Human Sperm Competition. in Sperm Competition and the Evolution of Animal Mating Systems pp. 602)

“This context for human sperm competition almost certainly exceeds all others in importance. Female extramarital sex occurs in 73.2% of indexed societies and is common in 57.1% (Fig 1I). The cross-cultural occurrence of male and female extra-marital sex is surprisingly similar (Fig 1J). Gaulin and Schlegel (1980) found low levels of paternity assurance in nearly half (N=61) of the 135 societies they examined. Presumably, sperm competition is especially intense in these societies. Kinsey et al. (1953) found ca. 26% of U.S. adult females had engaged in extra-martital intercourse, and over 50% of respondents in the Cosmopolitan survey (Wolfe 1981) indicated that they had had extramarital liaisons. Although similar data are not available for other cultures, it seems safe to assume that female extra-bond sex occurs in all but the most restrictive societies, and that it is common.” (Robert L. Smith (1984) Human Sperm Competition. in Sperm Competition and the Evolution of Animal Mating Systems pp. 609)

“In many cultures, however, choice of the first primary mate for a girl is made entirely by the parents and often exclusively by the daughter’s male parent (Levi-Strauss 1969), Daly and Wilson 1978, Symons 1979). The parents’ interests may, but probably will not be coincident with the daughter’s. Thus a parent-offspring conflict (see Trivers 1974) is created that may result in extramarital adventures by dissatisfied daughters.” (Robert L. Smith (1984) Human Sperm Competition. in Sperm Competition and the Evolution of Animal Mating Systems pp. 611)

“Chimpanzees are reproductively extraordinary among the great apes. They are not strikingly dimorphic for size as are the other two species (Fig 2), but male chimpanzees have enormous scrotal testes, proportionately about 5 and 10 times larger than Pongo and Gorilla, respectively, and a specialized penis more than twice as long as that on the much larger gorilla. Short (1981) has calculated that the testes of an averave chimpanzee can sustain sperm production at a level that will produce at least four full-strength ejaculates/day, each containing several times the number of sperm in an average gorilla or orangutan ejaculate.” (Robert L. Smith (1984) Human Sperm Competition. in Sperm Competition and the Evolution of Animal Mating Systems pp. 619)

“Masturbation seems a bizarre, maladaptive behavior because it wastes sperm, but the practice is almost universal among U.S. males and is particularly common in adolescents (Kinsey et al. 1948, Sorensen 1973). Masturbation is also commonly observed in some captive primates. It has been said that “primates masturbate, because they can,” but if autoeroticism were maladaptive, the tendency should have been repressed by natural selection. A clue to a possible function is found in the fact that males who do not ejaculate byu coitus or masturbation for some period of time experience nocturnal emissions, i.e. spontaneous seminal discharge chring sleep. This suggests that stored sperm and/or accessory gland products may have definite “shelf life” after which they are best discarded and replaced with new in order to stay competitive. Another possibility that has not been properly investigated is that frequent ejaculation may activate some feedback machansim (e.g. testosterone/inhibin) to stimulate higher levels of spermatogenesis and accessory gland secretion.” (Robert L. Smith (1984) Human Sperm Competition. in Sperm Competition and the Evolution of Animal Mating Systems pp. 633)

“Homo sapiens sapiens appeared sometime between 50,000 and 100,000 years BP, and was characterized by loss of robustness and changes in the female pelvis. The female skeletal changes are indicative of some change in pregnancy and births. These alternations may have includedd reduction in the gestation period from 11 months to the present 9 months and a concomitant increase in dependency of infants on parental care. The prediction is made on the basis of morphometric comparisons with the great apes and other mammal (Pilbeam 1984).” (Robert L. Smith (1984) Human Sperm Competition. in Sperm Competition and the Evolution of Animal Mating Systems pp. 633)

“Consortship would have gradually given way to long-term pairbonding with progressively higher levels of male investment in mates and offspring. Increased male investment coincided with the increased levels of paternity assurance that resulted from improved male efficiencies in controlling their mates’ reproductive activities. Selection strongly favored sexually jealous males who maintained tight control over their mates, and this progressively and substantially reduced the levels of sperm competition. Females evolved cryptic ovulation, perennial pendulous breasts, and behavioral deceptions to militate against male control efficiencies, and to achieve reproductive and other advantages from faculative polyandry. Paradoxically, female opportunity to secure advantages by faculative polyandry was created and propagated by the ability of males to mix high and low investment strategies.” (Robert L. Smith (1984) Human Sperm Competition. in Sperm Competition and the Evolution of Animal Mating Systems pp. 651)

“An excessively large penis produced by epigamic selection would be no less effective in delivering sperm than one of optimal length, but a substantially shorter (than optimal) penis would obviously place its owner’s ejaculates at a disadvantage in competition with those deposited by a longer organ. Therefore it may be possible to test some predictions of the ejaculate delivery/sperm competition hypothesis for human penis length and distinguish this function from one of display.” (Robert L. Smith (1984) Human Sperm Competition. in Sperm Competition and the Evolution of Animal Mating Systems pp. 631)

“The relative parental investment of the sexes in their young is the key variable controlling the operation of sexual selection. Where one sex invests considerably more than the other, members of the latter will compete among themselves to mate with members of the former. Where investment is equal, sexual selection should operate similarly on the two sexes. The pattern of relative parental investment in species today seems strongly influenced by the early evolutionary differention into mobile sex cells fertilizing immobile ones, and sexual selection acts to mold the pattern of relative parental investment. The time sequence of parental investment analyzed by sex is an important paramenter affecting species in which both sexes invest considerable parental care: the individual initially investing more (usually the female) is vulnerable to desertion. On the other hand, in species with internal fertilization and strong male parental investment, the male is always vulnerable to cukoldry. Each vulnerability has led to the evolution of adaptations to decrease the vulnerability and to counter-adaptations. Females usually suffer higher mortality rates than males in monogamous birds, but in nonmonogamous birds and all other groups, males usually sugger high rates. The chromosomal hypothesis is unable to account for the data. Instead, an adaptive interpretation can be advanced based on the relative parental investment of the sexes. In species with little or no male parental investment, selection usually favors male adaptations that lead to high reproductive success in one or more breeding seasons at the cost of increased mortality. Male competition is such species can only be analysed in detail when the distribution of females in space and time is properly described. Data from field studies suggest that in some species, size, mobility, experience and metabolic rate are important to male reproductive success. Female choice can augment or oppose mortality selection. Female choice can only lead to runaway change in male morphology when females choose by a relative rather than absolute standard, and it is probably sometimes adaptive for females to so choose. The relative parental investment of the sexes affects the criteria of female choice (and of male choice). Throughout, I emphasize the criteria that sexual selection favors different male and female reproductive strategies and that even when ostensibly cooperating in a joint task male and female interests are rarely identical.” (Parental investment and sexual selection (1972) Robert L. Trivers in Sexual selection and the descent of man 1871-1971 Campbell, Bernard (ed.) pp. 173)

"In so far as there is differential expression of the gene in the two sexes it will be subject to sexual selection, i.e., the effects of different criteria, or timing, of mate choice in the two sexes. Such selective influences will determine the range of variation maintained separately in the populations of males and females. These in turn will exert their effects through actions on the rate and degree of lateralization. Thus the sex difference in the rate of maturation may be secondary to the fact that mate choice (for optimal features of the species characteristic of language) occures at a later age in males than females (males are one to two years older than females at the time of marriage a difference that is consistent across cultures." (Crow TJ, Crow LR, Done DJ, Leask S (1998) Relative hand skill predicts academic abiltity: global deficits at the point of hemispheric indecision. Neuropsychologia : )

"Polynesians seem to value stoutness and large size in females. Males should be handsome, which seems to mean a healthy body. Both sexes should have light skin (Danielsson 1956: 69-73)" (Smith, James M. (1976) Sexual selection in recent human populations. California Anthropologist 6 (1): pp. 21)

"Edward Westermarck in his early classic A Short History of Marriage (1968: 126-155) discussed consent as a condition for marrige. Females, he noted, most often were married off at the will of some male-father, family elders, uncle. It is to be noted that the male partner in such marriages, also, had little personal choice. However, Westermarck pointed out that females in the simplest hunting and gathering societies could - and did - refuse the assigned mate. Sometimes she could do this directly and in other societies by subtle, indirect action. She lost much of this freedom in technologically more advanced societies. Some of the strongest arguments against male dominant choice of females as sex partners can be found in the statistical, cross-cultural work of George Murdock (1949: 20-21). Out of 241 societies where his criteria could be applied, 163 involved some consideration: bride-price, bride service, or exchange of women. In other words, families made the decisions rather than the individuals involved. Regarding divorce, Murdock (1969: 175-76) found, somewhat surprisingly, that in thirty of forty societies there were no substantial differences in the rights of men and women to terminate a marriage. Only 15 percent actually had the stereotyped view where men controlled the action. If divorce involved equal female choice, isn't it likely that she would have had much to say about the original marriage? Further analysis of mating practices in primitive society raises more questions as to male choice selecting for spedific traits. Murdock's worldwide sample of 25o societies (1949:263) showed that only three had a generalized sex taboo. Most of the others allowed premarital sex, extra-marital sex, wife-lending, etc., all of which could be involved in pregnancy with someone other than the social father." (Smith, James M. (1976) Sexual selection in recent human populations. California Anthropologist 6 (1): pp. 20)

"These studies suggest that prior evolutionary accounts have emphasized too strongly intrasexual mate competition as primarily a male activity. For these samples, at least, such competition appears to occupy women as much as men. Indeed, summing across all 23 tactics, there was no sex difference in overall performance frequency. Female-female competition appears to be an unnecessarily neglected area of research in social psychology and evolutionary biology (see Cunningham, 1986). Similarity exists strongly for the acts considered to be most effective. The acts frequently performed and considered highly effective for both sexes involve displaying sympathy, kindness, good manners, helpfulness, and humor. Since the characteristic kind-understanding emerges at or near the top of mate selection preferences for both sexes (Buss, 1985; Buss & Barnes, 1986), these results support the general hypothesis that mate selection criteria influence tactics of intrasexual mate competition, even for criteria that show no sex differences." (Buss, D.M. (1988) The evolution of human intrasexual competition: tactics of mate attraction. Journal Personality and Social Psychology 54 (4): pp. 625)

"Sexually interacting couples who produced a child together are more genetically similar than either randomly paired individuals or sexually interacting couples in which the male is excluded from paternity. The two sexually interacting groups combined share about 50% of measured genetic markers, part way between the mothers and their offspring who share 73%, and the randomly generated dyads who share 43%. Thus these results demonstrate that successful human mating follows lines of genetic similarity." (Rushton, J.P. (1988) Genetic similarity, mate choice, and fecundity in humans Ethology & Sociobiology 9 (6): pp. 332)

"Put another way, it has been observed that humans assort on the basis of the more genetically influenced of a set of traits. These data were predicted by genetic similarity theory, a formulation that extends the idea of kin selection by postulating that organisms have a tendency to favor any individual of similar genotype, regardless of whether or not they are "kin" (Rushton et al. 1984)." (Rushton, J.P. (1988) Genetic similarity, mate choice, and fecundity in humans Ethology & Sociobiology 9 (6): pp. 332)

“Young women appear to be attractive to young men owing to the combination of paedomorphic and secondary sexual signal characteristics which they present to them initially at a distance. Hairlessness, voice tone, complexion and girlish behavior all have a childlike character that in ethnological terms appear to lower the probability of a male aggressive response of to appease if one is present. These same characteristics are likely to reduce male fear and anxiety on closer approach and to permit sexual expression. The male begins to display in various “show-off” performances including physical prowess (such as, dancing), exhibitions of virtuosity in the social graces, in demonstrations of charm and sensitive virility. These displays attract the female’s attention and provide the basis upon which she may choose to respond to or reject the male’s approach: or more usually, simply fail to observe them. ... From the purely ethological viewpoint this sequence has much in common wiht courtship in birds and often mammals....” (Sexual selection in the primates (1972) John H. Crook in Sexual selection and the descent of man 1871-1971 Campbell, Bernard (ed.) pp. 274)

"It is these changes that created man as we know him, for by the advent of Homo erectus the irreversible change had taken place -- as measured by stature and brain size. And this is the crucial fact: the unprecedented rapidity of the evolution of the hominid brain (increase of three times inside of two million years) occurred exactly during the period when the scale of hunting increased - and increased in proportion. That is, exactly as the size and scale of prey increased, as did the size and complexity of the brain." (Fox, R (1983) Sexual selection, female choice and human kinship. Cambridge Anthropology 8,3: pp. 8)

"Perhaps the facial proportions that Jones interprets in terms of age cues also indexed some other aspect(s) of female mate value. One possibility is hormonal status, which Jones considers unlikely. Yet high androgen levels in women are positively correlated with reproductive system dysfunctions, and observable indices of high androgen levels, such as acne, hirsutism, and a high waist-to-hip ratio--seem to be systematically percieved as unattractive. To my eye, the faces in Jone's figure I apear to differ more in "masculinity" than in age." (Symons, D (1995) response to...Sexual selection, physical attractiveness, and facial neoteny: cross-cultural evidence and implications. Current Anthropology 36 (5): pp. 741-43)

"1. Women whose facial proportions make them look younger than their actual age (as measured by regression equations predicting age as a function of facial proportions) are perceived as more attractive by male raters from five populations (but see n. 4). 2. A sample of U.S. female models has significantly more neotenous facial proportions than a sample of U.S. female undergraduates and a strikingly low predicted age, about 7 years, according to regression equations predicting age as a function of facial proportions. 3. Cardioidol strain, a mathematical transformation shown by earlier research to provide a good model for changes in facial proportions during the course of maturation and to affect the percieved ages of faces, also has an effect on female facial attractiveness according to U.S. raters. The effect is nonlinear, suggesting that neoteny is a component of attractiveness only up to a certain point. 4. Results for male attractiveness in the above studies are weak and / or inconsistent." (Jones, Doug (1995) Sexual selection, physical attractiveness, and facial neoteny: cross-cultural evidence and implications. Current Anthropology 36 (5): pp. 734)

"The evolution of modern Homo sapiens over the past 100,000 years has been marked by a trend toward increasingly craniofacial neoteny, including reduced prognathism, increased brachycephaly, and general gracilization in a number of populations. (Weidenreich 1945, Newman 1962, Brace and Mahler 1971, Frayer 1981). Biological anthropologists have generally invoked natural selection for ecological adaptation of nonadaptive forces such as pleiotropy or biased mutation to explain these trends. The analysis in this paper suggests that sexual selection may also be involved." (Jones, Doug (1995) Sexual selection, physical attractiveness, and facial neoteny: cross-cultural evidence and implications. Current Anthropology 36 (5): pp. 735)

"Since, in comparison with genetic transmission, social transmission typically results in a more rapid diffusion of a preference through a population, culturally generated sexual selection may be unusually fast, and the alleles underlying favored traits may be selected to high frequency in just a handful of generations. This analysis suggests that (1) there should be local, society-specific correlations between favored traits and mating preferences; (2) sexual selection may account for cross-cultural variation in traits underlying attractiveness; and (3) recent selection may have modified any predilections favored throughout the Pleistocene." (Laland KN (1995) reply to.... Sexual selection, physical attractiveness, and facial neoteny: cross-cultural evidence and implications. Current Anthropology 36 (5): 728-9)

[quote from Gowaty, 1992, p. 231-240] "Juvenilization decreases the threat some men may feel when confronted with women; many men are comfortable around women whom they can clearly dominate and are profoundly uncomfortable around women whom they cannot so clearly dominant. The hypothesis that femininity signals ability to be dominated through juvenilization is an alternative to, but not necessarily mutually exclusive of, other evolutionary hypotheses that posit that femininity signals, sometimes deceptively, reproductive value and fertility." (Jones, Doug (1995) Sexual selection, physical attractiveness, and facial neoteny: cross-cultural evidence and implications. Current Anthropology 36 (5): pp. 727)

"Let us summarize the argument up to this point. Human beings are anomalous among sexually selected species in the importance attached to female (relative to male) appearance in mate choice. Human beings are anomalous in another respect as well: female fertility commonly declines to zero long before the end of the life span. As a result of menopause there is considerably more age-related variance in fecundity among adult females than among adult males in our species. The second anomaly may explain the first: the importance attached to female attractiveness in our species may reflect the operation of adaptations for assessing age-related changes in fecundity, a component of female mate value." (Jones, Doug (1995) Sexual selection, physical attractiveness, and facial neoteny: cross-cultural evidence and implications. Current Anthropology 36 (5): pp. 727)

"In other words, given that attractiveness varies with age, individuals may be more or less attractive than others of the same age in part because they have facial proportions associated with younger or older ages. Because the retention of traits from early stages of the life cycle into later stages, relative to ancestors or to other members of the population, is known as neoteny ("holding on to youth"), the proposition above may be rephrased: given that attractiveness varies with age, neoteny may be a component of facial attractiveness. This proposition may hold with particular force for female facial attractiveness: a by-product of the human male's attraction to markers of youthful fecundity may be an attraction to adult females presenting markers of youth to an exagerated or "supernormal" degree." (Jones, Doug (1995) Sexual selection, physical attractiveness, and facial neoteny: cross-cultural evidence and implications. Current Anthropology 36 (5): pp. 728)





"We must understand that a new creature was being forged here in the crucible of natural and sexual selection: a hunting ape-man. And in evolutionary terms it was a rapid change. The tensions therefore between the basic pattern and the new demands made upon it by the new creature are at the heart of the current human condition. The three blocks still had to accomadate to each other and make demands on each other, but this was under ever changing conditions. The major change, as we have seen, was in the origin ofthe division of labour between the sexes, which revolutionised not only the relations between the two sexes, but also the relations within the sexual groups." (Fox, R (1983) Sexual selection, female choice and human kinship. Cambridge Anthropology 8,3: pp. 10-11)

"We do have data from Japan that are highly suggestive. Here, for many centuries, fair skins have been under parental control and, other things being equal, parents seek attractive brides for their sons. As elsewhere, members of the upper classes tend to be the luckiest. This might be expected to lead to selection as the generations have gone by. Research which I conducted a few years ago (Hulse 1967) indicated that this has taken place, for upper-class high school students have the fairest skins and those of the lower class the darkest, while middle-class students are intermdiate in pigmentation. Furthermore, data from Greece (Friedl 1962) indicate that girls who are considered good-looking marry earlier than, and need not be supplied with as large a dowry as, their less-attractive sisters. Throughout southern Europe, the upper classes contain a disproportionate number of blondes and near-blondes. Sexual preferences, though they may be based on social snobbery rather than aesthetic interest, are capable of shifting allele frequencies in human population." (Hulse, F.S. (1978) Group selection and sexual selection in human evolution. in Evolutionary models and studies (Hague) Meier, R., Otten, C.M., Abdel-Hameed, F. (eds.), Moulton Publisher, Paris. p. 33)

"The major modification this produces in the sexual selection process is in the criteria for 'best genes' in the male. The one-male group species are most like the ungulates, with, or example, greater sexual dimorphism and special anatomical features for the male (the mane and 'cape' of the hamadyras for example). The multi-male species show less sexual dimorphism and specialisation, and capacities for group-living and organisation are obviously being selected for rather than mere strength or endurance or display. High-ranking female groups, for example, will often not tolerate males who are too aggressive and competitive, and these leave the group and become solitaries."(Fox, R (1983) Sexual selection, female choice and human kinship. Cambridge Anthropology 8,3: pp. 8)

"In earlier studies of sexual selection, the emphasis was heavily on the male competition and indeed selection does seem to work most spectacularly here. But it has more recently been seen that female choice may well be the ultimate determinant of the route selection will take. The males, as it were, exhaust themselves on competition, then the female groups pick out the winners as studs. Once it is realised that there can thus be considerable difference in reproductive success between the different female groups, the full dynamics of the system can be understood. The females' strategy has to be to pick the 'best' male, whatever the criteria. If a group of females can become inseminated by superior male genes, not only do their female offspring get the immediate advantages, but the chance of their 'sons' inseminating many groups of females itself increases. Thus, the genes of the original female kin-group will spread in the total population more successfully than those of rival groups. If we paraphrase Samuel Butler's famous statement (that a chicken is the egg's way of making another egg) and say that a male is the female's way of making more females (or that a male is the female kin-group's way of making another female kin-group) then we are getting close to the heart of the sexual selection process. But we have to see it, ultimately, as the stategy of the genes to produce replicas of themselves." (Fox, R (1983) Sexual selection, female choice and human kinship. Cambridge Anthropology 8,3: pp. 6-7)

"...the only consistent interest seen among the general primate population is an interest in novelty and variety. Although the possibility of choosing for good genes, good fathers, or good friends remains an option to female primates, they seem to prefer the unexpected." (Small, Meredith F. (1993) Female choices: Sexual behavior of female primates. Cornell Univ. Press, Ithaca, 1993 pp. 153)

"So if men did more of the hunting and scavenging whereas women did the bulk of the collecting of vegetables, women had essential jobs two million years ago. With time, these gender roles would select for men's knack for maps and mazes and other spatial skills, their aggressiveness, and their gross motor coordination. And as days turned into centuries, women's spatial memory for stationary objects, their verbal acuity, their facility for nurturing, their fine motor abilities, and their uncanny intuition would become firmly established as well." (Fisher, H. (1992) Anatomy of Love: The Mysteries of Mating, Marriage, and Why We Stray. Simon & Schuster, New York, 1992. pp. 203)

"We do not know why men have conspicuous genitals, but a male chimp solicits a female by opening his legs, displaying an erect penis and flicking his phallus with a finger as he gazes at a potential partner. A prominant, distinctive penis helps broadcast one's individuality and sexual vigor, which may lure female friends. In many species of insects and primates, males have exceptionally elaborate penises, and scientists think these evolved specifically because females chose those males with elaborate, sexally stimulating genitals. So perhaps as Lucy's ancestors became bipedal some four million years ago, males began to parade their genitals in order to make special friends with favored females--selecting for those with large organs." (Fisher, H. (1992) Anatomy of Love: The Mysteries of Mating, Marriage, and Why We Stray. Simon & Schuster, New York, 1992. pp. 177)

"This interest in novelty has been clearly documented for twelve species of primates (Small 1989). But more striking is the regularity with which females choose these males. Female chimps leave their natal group, copulate with neighboring males, and then return; patas monkey females roam the savannah looking for males other than their harem leader; squirrel monkey females seek extratroop males; monogamous gibbons also look to neighbors. In fact, the search for the unfamiliar is documented as a female preference more often than is any other characteristic our human eyes can percieve. Perhaps these females are concerned with inbreeding, and seeking new males is an easy way to ensure a mixture of genes for the offspring. Females, rather than males, should be the most worried about inbreeding because they have the largest investment in each conception (Huffman 1993). Their interest in novelty, therefore, might be a primitive urge to find mates lurking at the periphery of their group with genes different, but not completely different, from their own. Suzanne Ripley has suggested that avoiding inbreeding and gaining genetic diversity would be especially important in multimale-multifemale groups in which a ability to adapt in a changing world is paramount (1980). The evidence that this might be true comes from the genetic makeup of the animals themselves. Rhesus monkeys, perhaps the most evolutionarily successful primate after humans, are also highly genetically diverse (Melnick, Pearl, and Richard 1984, Ober et al. 1984). Although other authors have attributed this genetic diversity solely to male migration, it may be that females are more responsible in that they prefer to mate with outside males and place a forward spin on male transfer (Lindburg 1969, L.M. Wolfe 1986). In this sense, female choice is not a matter of females' choosing some males over others and making an impact on the genetic component of future generations, especially of their own offspring. For rhesus, Japanese macaques, and baboons, and perhaps for other nonhuman primates, the entire social system may be driven by what females prefer. The power of female choice, in this instance, is not just for mating--it exerts a potent evolutionary force on the entire social system." (Small, Meredith F. (1993) Female choices: Sexual behavior of female primates. Cornell Univ. Press, Ithaca, 1993 pp. 171-2)

"A predilection for novelty and variety might be explained in some cases as a mechanism to avoid inbreeding. We know that as animals inbreed the number of abnormal genes in a population increases. Conception rates go down and the number of genetic anomalies goes up. It seems that most animals, including humans, have built-in mechanisms to move away from the family group, not to mate with close relatives--to marry out. In non human primates, there's usually one sex that typically moves away from the family group at sexual maturity. Most often, it's males who move, but sometimes females leave. Another way females might avoid the evils of inbreeding is to mate with those less familiar, peripheral males. It might also be a good idea to produce offspring with various genetic heritage. If the environment changes, and several infants have all sorts of genes, at least one might make it. But it seems odd that females are drawn to these foreigners even when the resident males originally came from another troop. Perhaps they just aren't foreign enough." (Small, Meredith F. (1993) Female choices: Sexual behavior of female primates. Cornell Univ. Press, Ithaca, 1993 pp. 178)

"One characteristic among primates has been clearly targeted for possible selection by Fisherian female choice--male penis size. Primate males living in groups with many females and many males, groups in which promiscuity is the mating rule, have long penes (Dixon 1978). Male chimps, in fact, use their penes for display toward estrous females. Because a longer penis would give a female pleasure (note that the human male has the longest and thickest penis of any primate), female choice might have been a factor driving penis length to extremes among primates." (Small, Meredith F. (1993) Female choices: Sexual behavior of female primates. Cornell Univ. Press, Ithaca, 1993 pp. 109)

"Sexual selection requires (and provides a potential explanation for) a sexual dimorphism. For human cerebral function the most striking sex difference is in laterality (Bear et al, 1986) - men have a greater mean cerebral asymmetry than women (as noted by Crichton-Browne; see McGlone, 1980). This difference may account for the small but consistent differences that have been observed in the pattern of distribution of intellectual abilities - there is a mean difference for verbal fluency in favour of women and for spatial ability in favour of men (McGlone, 1980). The most striking sex difference if psychosis is earlier onset in men (Hafner et al, 1993; Lewine, 1991). Could the sex differences in cerebral organization (greater asymmetry and spatial ability in men; less asymmetry and greater verbal fluency in women) and the age of onset of psychosis be related? The following hypothesis (Crow, 1993a,b) (components of which are derived from earlier formulations as indicated in Table 3) relates them through Darwin's mechanism of sexual selection." (Crow TJ (1995) A Darwinian approach to the origins of psychosis. Br J Psychiatry 167(1):21)

"Some extreme varants are associated with the deviations of psychological function that we describe as psychosis. These states are seen as boundaries of the distribution of personality variation, including the capacity for language and emotional expression. In particular, those with the earliest manifestations (i.e. schizophrenia, Asperger's syndrome and autism) have the greatest impairments of communication and social ability, and also demonstrate a failure to develop anatomical asymmetry. In summary, key features of the theory are that the psychoses are disorders of specifically human evolution, arising from variation in the genes controlling hemispheric asymmetry that has led, by the mechanism of sexual selection, through progressive delay in maturation (neoteny) to increased brain size and intelligence. The most readily testable prediction is that the gene for asymmetry (and by implication contributing to predispostion to psychosis) should be X-Y homologous." (Crow TJ (1995) A Darwinian approach to the origins of psychosis. Br J Psychiatry 167(1):24)

[abstract] "BACKGROUND. The onset of psychotic illness in the reproductive phase of life with a decrease in fecundity (and approximately constant incidence across populations) requires an evolutionary explanation. What is thesurvival value of the predisposing gene or genes? METHOD. Evolutionary theories, including the author's, are reviewed and critically compared. RESULTS. Some theories (e.g. Huxley et al, 1964) postulate an advantage outside the nervous system: such theories fail to explain either the characteristic age distribution or constant incidence. More plausible are theories that relate the advantage to diversity of personality structure or social ability, or even to general intelligence, i.e. to the areas of function in which the phenomena of psychosis arise. CONCLUSIONS. It is argued that psychosis arises as the boundary of a distribution of variation in cerebral structure generated in the course of hominid evolution. Language played a central role, with the critical changes taking place on the basis of a mutation that allowed the two cerebral hemispheres to develop with a degree of independence. Sexual selection (differing criteria in females and males in choosing a mate) acting on this genetic innovation has generated a dimension of competence in social interaction in relation to which there has been a progressive increase in cerebral size by delayed maturation (neoteny). A sexual dimorphism in cerebral asymmetry and the sex difference in age of onset of psychosis can be parsimoniously explained if a gene regulating the relative growth of the two hemispheres is X-Y homologous." (Crow TJ (1995) A Darwinian approach to the origins of psychosis. Br J Psychiatry 167(1):12-25)

"It will be seen that, owing to the social structure of their troops, cynocephalus-group males will have the chance of mating with all the females as they come into oestrus, whereas the hamadryas male will be able to mate only with those females which he is able to attract into, and hold within, his own harem. Any physical feature which enables him to do this more effectively will thus be strongly favoured by natural selection, and, if it is acting as a signal of the 'competitive' or 'advertisment' type (Maynard Smith, 1962), would tend to become more conspicuous and exaggerated. There is reason to believe that the mane in such a feature." (Jolly, Clifford J. (1963) A suggested case of evolution by sexual selection in primates. Man (London) 63: 178)

"More convincing vestiges of a sexual selective history in which females mated polyandrously can be found in the human male. Perhaps the clearest such vestige is testis size (Short, 1977). Men's testes are substantially larger, relative to body size, than those of gorillas, a species in which males are polygynous but females mate monogamously so that "sperm competition" within the female reproductive tract is absent. (goes on to talk of chimpanzees) (Wilson, M., Daly, M. (1992) The man who mistook his wife for a chattel: The Adapted Mind; (Barkow, J.H. & Cosmides, L. & Tooby, J. eds.), Oxford Univ. Press, New York. p. 299)

"The contrast between non-social and social selective forces was reflected in Darwin's idea that, whereas natural selection would more or less grind to a halt in a constant environment, sexual selection was, in principle, capable of continuing indefinitely on its giddy spiral of ornamental exaggeration: 'In regard to structures acquired through ordinary or natural selection, there is in most cases, as long as the conditions of life remain the same, a limit to the amount of advantageous modification in relation to certain special ends; but in regard to structures adapted to make one male victorious over another, either in fighting or in charming the female, there is no definite limit to the amount of advantageous modification; so that as long as the proper variations arise the work of sexual selection will go on.' (Darwin 19871, i, p. 278) (Cronin, Helena (1992) The Ant and the Peacock: Cambridge Univ. Press, Cambridge p. 233)

"If males are signallying to females, then those signals are ripe for exploitation by a monstrous regiment of scavergers -- predators, parasites and competing males. ... And that is by no means the only kind of cost of being attractive. Sexual selection for increased body size in male birds invariably brings with it an increase in bill size, in some cases so great that males are forced to exploit suboptimal food niches (Selander 1972). The energetic costs of the males' display may be so high that they are pushed into abandoning safe foraging options for ones that possibly give higher energy returns but are more risky (Vehrencamp and Bradbury 1984). (Cronin, Helena (1992) The Ant and the Peacock: Cambridge Univ. Press, Cambridge p. 227)

"Fisher argued that choosing an attractive mate can be adaptive for a female because she will have attractive sons. In a population in which there is a majority preference for anything whatsoever, a female would do best to follow the fashion, however arbitrary, however absurd, because the next generation of daughters will inherit their mothers' preference whilst her sons will inherit their fathers' attractive feature." (Cronin, Helena (1992) The Ant and the Peacock: Cambridge Univ. Press, Cambridge p. 201)

"But what reinforces such a fashion, why does it spread? And why does it ever catch on in the first place? The fashion is fuelled by a tie between the preference gene and the ornament gene. Consider a female who has genes for preferring a long-tailed mate. Her offspring will inherit both her preference genes and her mate's long-tail genes, although the preference will be expressed phenotypically only in her daughters and the long tail only in her sons. So her union solders a connection between preferece genes and long-tail genes, a closer connection than would arise form random mating. (A measure of this tie is called the coefficient of linkage disequilibrium.) And the same will happen in subsequent generations. It is this connection that fuels the fashion. The more the females exercise a fashionable preference for long tails, the more the fashion is reinforced, each choice of long-tailed mate automatically being likely to select in favour of copies of genes for that very choice." (Cronin, Helena (1992) The Ant and the Peacock: Cambridge Univ. Press, Cambridge p. 202)

"Roger Short...had predicted that in {primate} species where females mate with more than one male during a reproductive cycle, the males would have larger testes for their body size than in species whose females had only a single mate per cycle. When the females were promiscous, the sperm of each male would have to compete with those of other males, and the male producing the most sperm was most likely to generate offspring. [quote from] (Harvey and Clutton-Brock 1983, p. 315" (Cronin, Helena (1992) The Ant and the Peacock: Cambridge Univ. Press, Cambridge p. 97)

"Overall, females apparently were choosing males who were sociable, cooperative, willing to share, and protective. In general, then, sexual intercourse would not be disruptive of either ongoing group interaction or organizational flexibility. Mothers obtained plant food from their own efforts, protein from a variety of sources (insects, plant protein, and some meat form their own efforts, and additional meat from males); had their own tools for protection; and had durable social bonds with sons, daughters, brothers, and sisters who shared the food quest and assisted in protective functions. Thus permanent mates to provide food and protection would be neither necessary nor particularly advantageous. Sexual preference was, however, getting easier to communicate, and it is likely that many australopithecines did have preferred sex partners." (Tanner, Nancy M. (1981) On Becoming Human: Cambridge University Press, Cambridge p. 210)

"Adult autralopithecine males would have had stonger social bonds with adult females, especially but not exclusively with their mothers and sisters, than is true for living chimpanzees. There was an even longer and more intense association with the mother and with siblings than for ancestral and transititional populations. Further incorporation of adult males into group life was made possible by increased sociability and decreased disruptiveness of the males (related both to the longer period of maternal care and socialization and to the probable decrease in sexual dimorphism, particularly in canine height). This relatively relaxed incorporation of males into the group was perhaps also reinforced by male contributions to defense and meat acquisition and by male help in bringing raw materials for tool manufacture from some distance to the campsite." (Tanner, Nancy M. (1981) On Becoming Human: Cambridge University Press, Cambridge p. 219)

"Overall, females apparently were choosing males who were sociable, cooperative, willing to share, and protective. In general, then, sexual intercourse would not be disruptive of either ongoing group interaction or organizational flexibility. Mothers obtained plant food from their own efforts, protein from a variety of sources (insects, plant protein, and some meat form their own efforts, and additional meat from males); had their own tools for protection; and had durable social bonds with sons, daughters, brothers, and sisters who shared the food quest and assisted in protective functions. Thus permanent mates to provide food and protection would be neither necessary nor particularly advantageous. Sexual preference was, however, getting easier to communicate, and it is likely that many australopithecines did have preferred sex partners." (Tanner, Nancy M. (1981) On Becoming Human: Cambridge University Press, Cambridge p. 210)

"He [Darwin] was prevented from harvesting all the fruits of his fertile imagination because he did not follow through with the logic of this own argument - to discover how female choice influenced the origin of the hominids; that is, to show how sexual selection was important at the very onset of human evolution. Because of an unfortunate blind spot engendered by his own cultural backround, Darwin was unable to explicate the necessary interrelationships and carry his own work on to its more logical conclusion." (Tanner, Nancy M. (1981) On Becoming Human: Cambridge University Press, Cambridge p. 167)

"Although some food and protection were supplied by males, sexual partners were only occasionally and irregularly involved; brothers and sons who frequently associated with mothers and sisters probably were the males who most regularly contributed animal protein and protection." (Tanner, Nancy M. (1981) On Becoming Human: Cambridge University Press, Cambridge p. 163)

"The more intelligent transitional female (remember, it is her offspring who will be most likely to survive) could use her intelligence to select males for copulation. In other words, increases in intelligence and a richer, more sophisticated communicatory repertoire mean the mating systemitself could become more complex. I hypothesize that the mating system was changing so as regularly to include female discrimination and choice of sex partners in terms of a number of characteristics. Females probably had sex more frequently with those males who were around often, playing with offspring, helping in protection, occasionally sharing meat and foraged plants, and who were generally friendly. With females choosing the less disruptive males, there also would be less likelihood that males having sex with mothers might accidentally injure offspring. To the extent that the ability to learn to be more sociable has been enhanced by genetic changes that have augmented our human potential --- and this is a subject about which little is known --- sexual selection in the hominid divergence also could have increased the capacity of males for relaxed social interaction. ... What may have been selected for among the transitional hominid males was the capacity to be extremely social but yet sufficiently aggressive when required and an ability to make fine discriminations as to situational necessity. Thus, the males of the transitional population would come to more closely resemble the females than had the males of the ancestral population. ... Much of the selection pressure engendered by female choice of sexual partners was directed toward male social and communicatory behavior, reinforcing the potential and capacity for sociability, social learning, and intelligence." (Tanner, Nancy M. (1981) On Becoming Human: Cambridge University Press, Cambridge p. 164-5)

"Heightened maternal investment resulted, in turn, in increased sexual selection by females. Natural and sexual selection reinforced each other during the transition. Selective pressures were intense, and evolutionary change may well have been extraordinarily rapid." (Tanner, Nancy M. (1981) On Becoming Human: Cambridge University Press, Cambridge p. 167)

Quote from Tutin, 1975: 448 in Tanner "As previously mentioned, female cooperation is essential for the maintenance of these special relationships and they thus present an opportunity for females to excercise choice. If female choice is involved, it is of interest to note that the selection criteria appear to be social and carefaking abilities of the males and not their dominance status." (Tanner, Nancy M. (1981) On Becoming Human: Cambridge University Press, Cambridge p. 97)

"When encroaching and receding glaciers forced our ancestors to reorganize and change their social behavior, human mating patterns may have undergone a shift such that sperm competition, the wanton promiscuity of the tropics, was no longer the norm; unsanctioned sexuality may have then become stigmatized as a punishable crime." (Margulis, L & Sagan, D. (1991) Mystery Dance, On the Evolution of Human Sexuality: Summit Books, New York pp. 54)

"Rampant female mating leads to competition not before but after copulation, not among bodies but among sperm. A female copulates with several males whose sperm compete to fertilize her. Sperm competition can occur even if a female copulates with different males several days apart. This is because sperm are hardy and may survive in the vagina of a chimpanzee or woman for as long as eight or nine days. Any female who copulates with more than a single male while ovulating opens the gates to a sperm race. The males or men who produce the sperm are not direct entrants; they are more like corporate sponsors advertising their name and providing financial backing. Not all participants in the all-male marathon are equally prepared to win. Mammals who mate more frequently, and produce more sperm per ejaculation, are more likely to impregnate their partners. Favoring the sperm of one male over that of competitors are such things as position during intercourse, force and timing of pervic thrusting, number and speed to ejaculated sperm, and proximity of the spermatic means of delivery---the penis---to the egg at time of ejacultion. Copious sperm production (estimated by testicle weight), deep penetration, and an elongated penis are all presumably advantages to males engaged in sperm competition. Perhaps most important is sheer sexual vigor, with more active males ejaculating the greatest number of times gaining a competitive edge. The charm and proficiency of a male---his ability to seduce a female and to continue to please after seducing her---of course also crucially determine his chances of entering and therefore of winning the competition; and in this sense females make the great impact of generally deciding who will and will not compete. There is also evidence that a woman who climaxes while making love to her lover is more likely to become pregnant by him." (Margulis, L & Sagan, D. (1991) Mystery Dance, On the Evolution of Human Sexuality: Summit Books, New York pp. 37)

"Large testes and big penises are advantages only under conditions of widespread sexual promiscuity. Among our closest relatives the great apes, only male chimpanzees have testicles more prodigious than those of men. And chimps, with their big, heavy testicles, are more sexually promiscuous than humans. that the sperm-producing organs of chimps and humans are relatively big and heavy strongly suggests that some of our not-so-distant hominid ancestors were far more promiscuous than gorillas and orangutans --- or than many people are today. In the evolutionary past, the competition to reach primate eggs was sometimes between sperm from different male donors. If two or more males copulated with the same female within a period of days, an advantage in begetting offspring accrued to the one who ejaculated the greatest quantity of vigorous sperm cells. Like an auto race won by the driver whose sponsoring company can afford to provide him with the most souped-up car, the male with the best-timed copulation, most far-reaching ejaculation, and biggest testicular "engine" able to produce the greatest quantity of sperm tended to win the "game" of impregnation. souped-up genitals with a lot of spermatic firepower, like incredibly expensive streamlined racing cars, are worth it only if there is some sort of race or contest. Otherwise they seem expensive." (Margulis, L & Sagan, D. (1991) Mystery Dance, On the Evolution of Human Sexuality: Summit Books, New York pp. 33)

"The large average size of the human penis (five to six inches, versus three for chimps, and one-half that for gorillas) may have been, evolutionists speculate, to frighten other males. Or to attract females. Or to enhance their pleasure. Perhaps the best hypothesis is that the longer penis delivers sperm more closely to the eggs: today's biologists claim that for females who mated with several males, the male with the longest penis delivered his sperm more safely." (Margulis, L & Sagan, D. (1991) Mystery Dance, On the Evolution of Human Sexuality: Summit Books, New York pp. 23)

<104(51)> "Darwin proposes two kinds of sexual selection --- competition among males for access to females, and choice exercised by females themselves. He attributed much of the racial differentiation among modern humans to sexual selection, based upon different criteria of beauty that arose among various people."

<104(56)> Gould quoting Wallace " 'the habits of savages give no indication of how this faculty could have been developed by natural selection, because it is never required or used by them. The singing of savages is a more or less monotonous howling, and the females seldom sing at all. Savages certainly never choose their wives for fine voices, but for rude health, and strength, and physical beauty. Sexual selection could not therefore have developed this wonderful power, which only comes into play among civilized people. It seems as if the organ had been prepared in anticipation of the future progress in man, since it contains latest capacities which are uselss to him in his earlier condition.' "

<110(73)> "We would like to know more about our uniquenesses, what it means to be human, how something like us could arise from something like a chimpanzee. Understanding this process involves learning more about the remotest roots of prehistoric art, what came before, and its selective, adaptive value for the survival of the species."

"With respect to the origin of articulate language, after having read on the one side the highly interesting works of Mr. Hensliegh Wedgwood, the Rev. F. Farrar, and Prof. Schleicher, and the celebrated lectures of Prof. Max Muller on the other side, I cannot doubt that language owes its origin to the imitation and modification of various natural sounds, the voices of other animals, and man's own instinctive cries, aided by signs and gestures. When we treat of sexual selection we shall see that primeval man, or rather some early progenitor of man, probably first used his voice in producing true musical cadences, that is in singing, as do some of the gibbon-apes at the present day; and we may conclude from a widely-spread analogy, that this power would have been especially exerted during the courtship of the sexes,---would have expressed various emotions, such as love, jealously, triumph,---and would have served as a challenge to rivals. It is, therefore, probable that the imitation of musical cries by articulate sounds may have given rise to words expressive of various complex emotions. The strong tendency in our nearest allies, the monkeys, in microcephalous idiots, and in the barbarous races of mankind, to imitate whatever they hear deserves notice, as bearing on the subject of imitation. Since monkeys certainly understand much that is said to them by man, and when wild, utter signal-cried of danger to their fellows; and since fowls give distinct warnings for danger on the ground, or in the sky form hawks (both, as well as a third cry, intelligible to dogs), may not some unusually wise ape-like animal have imitated the growl of a beast of prey, and thus told his fellow-monkeys the nature of the expected danger? this would have been a first step in the formation of a language." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 89-90)

"Sense of Beauty.---This sense has been declared to be peculiar to man. I refer here only to the pleasure given by certain colors, and sounds, and which may fairly be called a sense of the beautiful; with cultivated men such sensations are, however, intimately associated with complex ideas and trains of thought. When we behold a male bird elaborately displaying his graceful plumes or splendid colors, before the female, whilst other birds, not thus decorated, make no such display, it is impossible to doubt that she admires the beauty of her male partner. As women everywhere deck themselves with these plumes, the beauty of such ornaments cannot be disputed. As we shall see later, the nests of humming-birds, and the playing passages of bower-birds are tastefully ornamented with gaily-colored objects; and this shows that they must receive some kind of pleasure from the sight of such things. With the great majority of animals, however, the taste for the beautiful is confined, as far as we can judge, to the attractions of the opposite sex." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 95)

"It may be suggested that in some cases a double process of selection has been carried on; that the males have selected the more attractive females, and the latter the more attractive males. This process, however, though it might lead to the modification of both sexes, would not make the one sex different from the other, unless indeed their tastes for the beautiful differed; but this is a supposition too improbable to be worth considering in the case of any animal, excepting man." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 233-4)

"In regard to structures acquired through ordinary or natural selection, there is in most cases, as long as the conditions of life remain the same, a limit to the amount of advantageous modification in relation to certain special purposes; but in regard to structures adapted to make one male victorious over another, either in fighting or in charming the female, there is no definite limit to the amount of advantageous modification; so that as long as the proper variations arise the work of sexual selection will go on. This circumstance may partly account for the frequent and extraordinary amount of variability presented by secondary sexual characters. Nevertheless, natural selection will determine that such characters shall not be acquired by the victorious males, if they would be highly injurious, either by expending too much of their vital powers, or by exposing them to any great danger. The development, however, of certain structures---of the horns, for instance, in certain stags---has been carried to a wonderful extreme; and in some cases to an extreme which, as far as the general conditions of life are concerned, must be slightly injurious to the male. From this fact we learn that the advantages in battle or courtship, and thus leaving a numerous progeny, are in the long run greater than those derived from rather more perfect adaptation to their conditions of life. We shall further see, and it could never have been anticipated, that the power to charm the female has sometimes been more important than the power to conquer other males in battle." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 235)

"Sexual selection, which implies the possession of considerable perceptive powers and of strong passions, seems to have been more effective with the Lamillicorns than with nay other family of beetles. With some species that males are provided with weapons for fighting; some live in pairs and show mutual affection; many have the power of stridulating when excited; many are furnished with the most extraordinary horns, apparently for the sake of ornament; and some, which are diurnal in their habits, are gorgeously colored. Lastly, several of the largest beetles in the world belong to this family, which was placed by Linnaeus and Fabricius at the head of the Order." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 311)





"It does not, however, follow because snakes have some reasoning power, strong passions and mutual affection, that they should likewise be endowed with sufficient taste to admire brilliant colors in their partners, so as to lead to the adornment fo the species throught sexual selection. Nevertheless, it is difficult to account in any other manner for the extreme beauty of certain species..." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 364)

"Many instances have already been given of the partial transference of secondary masculine characters to the female, so that it is not at all surprising tht the females of some species should possess the power of song." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 382)

"As shown in a previous chapter, singing is to a certain extent an art, and is much improved by practice. Birds can be taught various tunes, and even the unmelodious sparrow has learnt to sing like a linnet." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 382)

" It is also remarkable that birds which sing well are rarely decorated with brilliant colors or other ornaments. ... Hence bright colors and the power of song seem to replace each other." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 383)

"As any fleeting fashion in dress comes to be admired by man, so with birds a change of almost any kind in the structure or coloring of the feathers in the male appears to have been admired by the female. The fact of the feathers in widely distinct groups having been modified in an analogous manner no doubt depends primarily on all the feathers having nearly the same structure and manner of development, and consequently tending to vary in the same manner." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 396)

"Many will declare that it is utterly incredible that a female bird should be able to appreciate fine shading and exquisite patterns. It is undoubtedly a marvellous fact that she should possess this almost human degree of taste. He who thinks that he can safely guage the discrimination and taste of the lower animals may deny that the female Argus pheasant can appreciate such refined beauty; but he will then be compelled to admit that the extraordinary attitudes assumed by the male during the act of courtship, by which the wonderful beauty of his plumage is fully displayed, are purposeless; and this is a conclusion which I for one will never admit." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 412)

" No doubt the males of some obscurely colored birds fight desperately together, but it appears that when sexual selection has been highly influencial, and has given bright colors to the males of any species, it has also bery often given a strong tendency to pugnacity." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 413)

"Fromthe forgoing facts we clearly see that the plumes and other ornaments of the male must be of the highest importance to them; and we further see that beauty is even sometimes more important than success in battle." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 416)

"But there remains a question which has an all-important bearing on sexual selection, namely, does every male of the same species excite and attract the female equally? Or does she exert a choice, and prefer certain males? This latter question can be answered in the affirmative by much direct and indirect evidence." {referring to birds} (Darwin, C. (1871) The Descent of Man . John Murray: London p. 417)

"With respect to female birds feeling a preference for particular males, we must bear in mind that we can judge of choice being exerted only by analogy. If an inhabitant of another planet were to behold a number of young rustics at a fair courting a pretty girl, and quarrelling about her like birds at one of their places of assemblage, he would, by the eagerness of the wooers to please her and to display their finery, infer that she had the power of choice. Now with birds the evidence stands thus: they have acute powers of observation, and they seem to have some taste for the beautiful both in color and sound. It is certain tht the females occasionally exhibit, from unknown causes, the strongest antipathies and preferences for particular males." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 434)

"W can judge, as already remarked, of choice being exerted, only from analogy; and the mental powers of birds do not differ fundamentally from ours. From these various considerations we may conclude that the pairing of birds is not left to chance; but that those males, which are best able by their various charms to please or excite the female, are under ordinary circumstances accepted. If this be admitted, there is not much difficulty in understanding how male birds have gradually acquired their ornamental characters. All animals present individual differences, and as man can modify his domesticated birds by selecting the individuals which appear to him the most beautiful, so the habitual or even occasional preference by the female of the more attractive males would almost certainly lead to their modification; and such modifications might in the course of time be augmented to almost any extent, comparable with the existence of the species." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 435-6)

"It would even appear that mere novelty, or slight changes for the sake of change, have sometimes acted on female birds as a charm, like changes of fashion with us." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 511)

"Hence with respect to taste, which depends on many elements, but partly on habit and partly on a love of novelty, there seems no improbability in animals admiring for a very log period the same general style of ornamentation or other attractions, and yet appreciating slight changes in colors, form, or sound." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 513)

"With mammals we do not at present possess any evidence that the males take pains to display their charms before the female; and the elaborate manner in which this is performed by male birds and other animals is the strongest argument in favor of the belief that the females admire, or are excited by, the ornaments and colors displayed before them. There is, however, a striking parallelism between mammals and birds in all their secondary sexual characters, namely in their weapons for fighting with rival males, in their ornamental appendages, and in their colors. In both classes, when the male differs from the female, the young of both sexes almost always resemble each other, and in a large majority of cases resemble the adult female. In both classes the male assumes the characters proper to his sex shortly before the age of reproduction; and if emasculated at an early period, loses them. in both classes the change of color is sometimes seasonal, and the tints of the naked parts sometimes become more vivid during the act of courtship. In both classes the male is almost always more vividly or stongly colored than the female, and is ornamented with larger crests of hair of feathers, or other such appendages. In a few exceptional cases the female in both classes is more highly ornamented than the male. With many mammals, and at least in the case of one bird, the male is more odoriferous than the female. In both classes the voice of the male is more powerful than that of the female. Considering this parallelism, there can be little doubt that the same cause, whatever it may be, has acted on mammals and birds; and may be attributed, as it appears to me, to the long-continued preference of the individuals of one sex for certain individuals of the opposite sex, combined with their success in leaving a larger number of offspring to inherit their superior attractions." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 560)

"The law of the equal transmission of characters to both sexes, as far as color and other ornaments are concerned, has prevailed far more extensively with mammals than with birds; but weapons, such as horns and tusks, have often been transmitted either exclusively or much more perfectly to the males than to the females." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 574)

Description by Darwin of neotonous elements of human females. (Darwin, C. (1871) The Descent of Man . John Murray: London p. 576-7)

"...and nearly all these measurements show that the males differ much more from one another than do the females. This fact indicates that, as far as these characters are concerned, it is the male which has been chiefly modified, since the several races diverged from their common stock." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 580)

"The capacity and love for singing or music, though not a sexual character in man, must not here be passed over. Although the sounds emitted by animals of all kinds serve many purposes, a strong case can be made out, that the vocal organs were primarily used and perfected in relation to the propagation of the species. " (Darwin, C. (1871) The Descent of Man . John Murray: London p. 587)

"In the class of Mammals, with which we are here more particularly concerned, the males of almost all the species use their voices during the breeding-season much more than at any other time; and some are absolutely mute excepting at this season. With other species both sexes, or only the females, use their voices as a love-call. Considering these facts, and that the vocal organs of some quadrupeds are much more largely developed in the male than in the female, either permanently or temporarily during the breeding-season; and considering that in most of the lower classes the sound produced by the males, serve not only to call but to excite or allure the female, it is a surprising fact that we have not as yet any good evidence that these organs are used by male mammals to charm the females. The American Mycetes caraya perhaps forms an exception, as does the Hylobates agilis, an ape allied to man. This gibbon has an extremely loud but musical voice." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 587-8)

"But if it be further asked why musical tones in a certain order and rhythm give man and other animals pleasure, we can no more give the reason than for the pleasantness or certain tastes and smells. That they do give pleasure of some kind to animals, we may infer from their being produced during the season of courtship by many insects, spiders, fishes, amphibians, and birds; for unless the females were able to appreciate such sounds and were excited or charmed by them, the persevering efforts of the males, and the complex structures often possessed by them alone, would be useless; and this it is impossible to believe." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 590)

"All these facts with respect to music and impassioned speech become intelligible to a certain extent, if we may assume that musical tones and rhythm were used by our half-human ancestors, during the season of courtship, when animals of all kinds are excited not only by love, but by the strong passions of jealousy, rivalry, and triumph. From the deeply-laid principle of inherited associations, musical notes in this case would be likely to call up vaguely and indefinitely the strong emotions of a long-past age. As we have every reason to suppose that articulate speech is one of the latest, as it certainly is the highest, of the arts acquired by man, and as the intinctive power of producing musical notes and rhythms is developed low down in the animal series, it would be altogether opposed to the principle of evolution, if we were to admit that man's musical capacity has been developed from the tones used in impassioned speech. We must suppose that the rhythms and cadences or oratory are derived from previously developed musical powers. We can thus understand how it is that music, dancing, song, and poetry are such very ancient arts. We must go even further than this, and, as remarked in a former chapter, believe that musical sounds afforded one of the bases for the development of language." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 593)

"As the males of several quadrumana animals have their vocal organs much more developed than in the females, and as a gibbon, one of the anthropomorphous apes, pours forth a whole octave of musical notes and may be said to sing, it appears probably that the progenitors of man, either the males or females or both sexes, before acquiring the power of expressing their mutual love in articulate language, endeavored to charm each other with musical notes and rhythm." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 593-4)

"In most, but not all parts of the world, the men are more ornamented than the women, and often in a different manner; sometimes, though rarely, the women are hardly at all ornamented. As the women are made by savages to perform the greatest share of the work, and as they are not allowed to eat the best kinds of food, so it accords with the characteristic selfishness of man that they should not be allowed to abtain, or use the finest ornaments. Lastly, it is a remarkable fact, as proved by the foregoing quotations, that the same fashions in modifying the shape of the head, in ornamenting the hair, in painting, tatooing, in teeth, etc., now prevail, and have long prevailed, in the most distant quarter of the world. It is extremely improbable that these practices, followed by so many distinct nations, should be due to tradition from any common source. They indicate the close similarity of the mind of man, to whatever race he may belong, just as do the almost universal habits of dancing, masquerading, and making rude pictures." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 598)

"With mammals the general rule appears to be that characters of all kinds are inherited equally by the males and females; we might therefore expect that with mankind any characters gained by the females or by the males through sexual selection would commonly be transferred to the offspring of both sexes. If any change has thus been effected, it is almost certain that the different races would be differently modified, as each had its own standard of beauty." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 607)

"The indirect evidence in favor of the belief of the former prevalence of communal marriages is strong, and rests chiefly on the terms of relationship which are employed between the members of the same tribe, implying a connection with the tribe, and not with either parent. But the subject is too large and complex for even an abstract to be here given, and I will confine myself to a few remarks. It is evident in the case of such marriages, or where the marriage tie is very loose, that the relationship of the child to its father cannot be known. But it seems almost incredible that the relationship of the child to its mother should ever be comnpletely ignored, especially as the women in most savage tribes nurse their infants for a along time. Accordingly, in many cases the lines of descent are traced through the mother alone, to the exclusion of the father. But in other cases he terms employed express a connection with the tribe alone, to the exclusion of the mother. It seems possible that the connection between the related members of the same barbarous tribe, exposed to all sorts of danger, might be so much more important, owing to the need of mutual protection and aid, than that between the mother and her child, as to lead to the sole use of terms expressive of the former relationships; but Mr. Morgan is convinced that this view is by no means sufficient." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 610)

Darwin refers to J. Lubbock's work that suggests that former culture emphasized that females be, "utterly licentious". (Darwin, C. (1871) The Descent of Man . John Murray: London p. 611)

Darwin describes the evidence favoring promiscous cultures in the past. Then goes on..."Nevertheless, from the strength of the feeling of jealousy all through the animal kingdom, as well as from the analogy of the lower animals, more particularly of those which come nearest to man, I cannot believe that absolutely promiscous intercourse prevailed in times past, shortly before man attained to his present rank in the zoological scale." ..."We may indeed conclude from what we know of jealousy of all male quadrupeds, armed as many of them are, with special weapons for battling with their rivals, that promiscous intercourse in a state of nature is extremely improbable." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 611-12)

"Therefore, looking far enough back in the stream of time, and judging form the social habits of man as he now exists, the most probably view is that he aboriginally lived in small communities, each with a single wife, of if powerful with several, whom he jealously guarded against all other men." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 612)

"...for hardly any other cause, except the scarcity of women seems sufficient to break down the natural and widely prevalent feeling of jealousy, and the desire of each male to possess a female for himself. ....Both sexes, if the female as well as the males were permitted to exert any choice, would choose their partners not for mental charms, or property, or social position, but almost solely from external appearance." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 616)

"Man is more powerful in body and mind than woman, and in the savage state he keeps her in a far more abject state of bondage than does the male of any other animal; therefore it is not surprising that he should have gained the power of selection." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 619)

"As the body in woman is less hairy than in man, and as this character is common to all races, we may conclude that it was our female semi-human ancestors who were first divested of hair, and that this occured at an extremely remote period before the races had diverged from a common stock. Whilst our female ancestors were gradually acquiring this new character of nudity, they must have transmitted it almost equally to their offspring of both sexes whilst young; so that its transmission, as with the ornaments of many mammals and birds, has not been limited either by sex or age. There is nothing surprising in a partial loss of hair having been esteemed as an ornament by our ape-like progenitors, for we have seen that innumerable strange characters have been thus esteemed by animals of all kinds, and have consequently been gained through sexual selection. Nor is it surprising that a slightly injurious character should have been thus acquired; for we know that this is the case with the plumes of certain birds, and with the horns of certain stags." (Darwin, C. (1871) The Descent of Man . John Murray: London p. 623)