Boyd, R., & P. J. Richerson (1992). Punishment allows the evolution of cooperation (or anything else) in sizable groups. Ethology and Sociobiology 13:171-195.
Richerson, P. J., & R. Boyd (1997). The evolution of human ultra-sociality. In Ideology, Warfare, and Indoctrinability, ed. I. Eibl-Eibesfeldt & F. Salter. Oxford and Providence: Berghahn Books.
Wilson, D. S., & E. Sober (1994). Re-introducing group selection to the human behavioral sciences. Behavioral and Brain Sciences 17:585-684.
by PENNY ANTHON GREEN, New College, St. Edward's University, P.O. Box
3001 South Congress Avenue, AUSTIN, TX 78704-6489, U.S.A.
The starting point of John Archer's volume is the predominantly male nature of human
violence, conceptualized as aggressive behavior that causes or has the potential to cause
injury or death. While the book ostensibly focuses on male violence, many of the chapters
address both aggression and violence, and the terms are sometimes used interchangeably.
Some chapters focus on both evolutionary and more proximate causes of aggression and
violence; others emphasize one or the other.
The book is divided into four parts, the first of which addresses aggression in childhood. Included are two chapters examining behavioral differences between boys and girls. Michael J. Boulton's chapter begins by reviewing the literature on "rough and tumble play." It then presents new research findings indicating that, in agreement with extant literature, boys engage in this activity more frequently than girls. Emphasizing the need for further research into the developmental components of aggression, the chapter concludes that we must presently "resist the temptation to cast too critical an eye over play-fighting activities or to view them as precursors of serious aggression" (p. 39).
A second chapter on gender differences, by Yvette Ahmad and Peter K. Smith, examines types and patterns of bullying. In general, boys bully more frequently than girls. The authors note, however, that the forms of bullying typically engaged in by girls are more subtle than those used by boys. Consequently, some female bullying may have been missed by researchers using male-based models.
Glenn Weisfeld's chapter conceptualizes aggression as a strategy that evolved in response to the reproductive advantages associated with dominance. The strategy shows itself in human males at about three years of age; it becomes more prevalent during adolescence as a means for acquiring and maintaining dominant status. Aggressive encounters typically decline as the dominance order stabilizes, with two notable exceptions. "Aggressive subordinates" are males who do not accept their subordinate position and frequently use aggression to try to improve it, usually unsuccessfully. "Aggressive dominants" are bullies, who despite high status, continue to aggress against lower-ranking individuals.
Part Two examines inter-male violence. Arnold P. Goldstein's chapter focuses on delinquent gangs. It discusses how they have been conceptualized historically, how social science theories used to explain them, their members' demographic characteristics, and some intervention strategies used to divert young men away from them. Barry McCarthy's paper considers the historical and cross-cultural linkages between "warrior values" (i.e., physical courage, endurance, strength and skill, and honor) and socially-constructed definitions of masculinity.
The final chapter in Part Two, by John Archer, uses crime statistics (e.g., homicide rates) to demonstrate that violence is more common among males than females. These statistics show that both offenders and victims come disproportionately from among the poor and unemployed. Focusing on the bar as a setting where much male violence occurs, especially among young working class males, the author discusses how game theory enhances our understanding of the escalation process in aggressive encounters. He examines interaction sequences in both humans and non-humans, and considers how the human additions of weapons and alcohol influence the escalation process. Archer also reviews literature indicating that violence prone men typically exhibit callous attitudes toward sex, view violence as manly, and consider danger to be exciting.
Part Three focuses on violence against women and children. Robin Goodwin's chapter argues that most research on aggression in male-female relationships has ignored the historical and cultural contexts within which the aggression occurs, as well how these contexts influence the meaning that it has for both perpetrators and victims. Goodwin advocates cross-cultural research aimed at identifying cultural variables (e.g., where a society's values fall along an individualistic-collectivistic continuum) that influence the probability of violence toward women.
Neil Frude uses an 'interactionist' model to illuminate behavioral sequences leading to violence in intimate relationships. The model incorporates societal influences (e.g., poverty and unemployment), marital factors (e.g., power relations, couple conflict style), personality variables in both assailants and victims, common precipitating events (e.g., sexual issues, money), the role of alcohol, and the form of violent expression (e.g., hitting, kicking).
Paul Pollard examines sexual violence against women, with an eye toward characterizing male offenders. His literature review indicates that high levels of sexual arousal to rape depictions, considerable sexual experience and multiple partners, adherence to 'rape-tolerant' attitudes, hostile attitudes toward women, and a sexually aggressive male peer group are consistently related to self-reports of sexual aggression.
The chapter by Bernice Andrews discusses findings from her London study of child abuse, which focuses on mothers and their daughters. The study reveals that fathers (or father substitutes) are approximately twice as likely as mothers (or mother substitutes) to abuse. Family structure is a weak indicator of abuse, with the probability increasing only slightly when a father substitute is present. The study also indicates that maternal depression raises the likelihood of abuse by fathers (or father substitutes), and by people outside the home as well. The linkage seemingly involves the higher incidence of neglect and/or 'poor mothering' by depressed women.
In the final chapter of Part Three, Kevin Browne provides an extensive review of the child abuse literature. Topics include the extent and types of early sexual maltreatment, characteristics of offenders, consequences of abuse for victims, and the process through which child victims are transformed into adult offenders.
The six chapters in Part Four provide explanations and theoretical perspectives on male aggression and violence. The first, by Angela K. Turner, examines the literature on genetic and hormonal influences. The admittedly sketchy evidence suggests substantial genetic influences on such personality traits as emotionality, sensation-seeking, and impulsiveness - traits that presumably increase the probability of aggressive, anti-social behavior. Any direct genetic influences on aggression and violence appear small. Positive associations are found between testosterone levels and various forms of aggression, but it is difficult to distinguish causes from effects.
The chapter by Martin Daly and Margo Wilson considers the evolutionary psychology of male violence. It begins by reviewing the assumptions made by evolutionary psychologists and discusses some research questions that they typically ask about the human psyche and its aggressive response to specific proximate cues. The adaptiveness of aggression and violence is then examined within the context of specific relationship settings (i.e., same-sex rivals, sexual conflict, and parent-offspring conflict). The chapter concludes by addressing the question of why violence is a predominately male phenomenon, especially one that characterizes young adult males.
The chapter by John P. Hoffmann, Timothy O. Ireland, and Cathy Spatz Widom reviews and critically evaluates some traditional socialization theories of aggression (i.e., psychoanalytic, frustration-aggression, social learning, and social cognitive). Based on their evaluation, the authors suggest additional questions that the aforesaid theories should address. First, to what extent do these theories, which were developed to explain aggression and anti-social delinquency, also explain violence? Second, to what degree are they able to incorporate a developmental perspective on aggression? Third, to what extent is aggression caused by forces located in an individual's family, peer group, and societal environment? Fourth, what role do gender differences play in influencing levels of aggression? And finally, what do the targets of violence tell us about its causes?
John Archer's chapter presents a power explanation for male violence that has two interrelated components. One involves the physical force and structural power that men use when attempting to control female sexuality. The second concerns inter-male contests for power--contests that frequently turn violent. These two components are linked empirically, in that men who are violent with their female partners also tend to use violence against other men. They are also linked ideologically. Violent males tend to feature a belief system that justifies using violence both as a means to acquire status vis a vis other males, as well as to control female behavior.
Anne Campbell and Steven Muncer attempt to explain why male violence tends to be 'instrumental' (i.e., directed toward achieving some end), whereas female violence is typically 'expressive' (i.e., occurring in response to high levels of stress or anger). They argue that this variance arises out of differing "social representations" of violence that are part and parcel of gender socialization, but make no attempt to explain why these, as opposed to alternative representations, are part of the social fabric. The authors conclude by saying that genuinely powerful men rarely use violence; rather it tends to be characteristic of men in relatively powerless positions or whose power is threatened.
The book's final chapter, by Paul Gilbert, aims at integrating insights by scholars working at different levels of explanation. Gilbert begins by considering how evolution has seemingly shaped certain broad categories of social behavior (e.g., bonding, status attainment) that are relevant to aggression and violence. He also considers how violence evolved as an evolutionary stable strategy for acquiring and maintaining control over resources. Despite its evolutionary origins, the linkage between violence, as a strategy, and specific behavioral episodes is complex. It is mediated by social contextual variables, including cultural values, prevailing structural arrangements, and stages of individual development. Gilbert concludes that the seriousness of male violence arises largely from our downplaying the human capacities for empathy, caring, and forgiveness--also components of our evolved behavioral repertoire. This trivialization derives from prevailing structural arrangements (e.g., capitalist economies) which construct social identities around such themes as competitiveness and status.
Overall, I was very impressed with Male Violence. It provides a wealth of information about an important, complex problem. Most of the chapters, either implicitly or explicitly, acknowledge a biocultural etiology of male violence, thereby inviting contributions from social scientists who have previously felt excluded from the evolutionary dialogue. Given this overall evaluation, the following comments should be viewed more as suggestions for further research than as criticisms. To begin with, I hope researchers will avoid the seductive trap of relying exclusively on readily available data sources. Several chapters in Male Violence used violent crime statistics (e.g., homicide rates). In principle, there is no harm in this. But if we are to understand male violence in all of its varying forms, researchers also need to examine more subtle forms of violence. Decision making within corporate board rooms provides a good example. In terms of overall magnitude, white collar and corporate criminals inflict considerably more physical and economic harm on their victims than do street criminals, at least in the United States. For instance, a corporate decision to dispose of toxic wastes illegally can and sometimes does cause illness and death for those unfortunate enough to be exposed to it. The decision to dispose illegally of these wastes is an act of male violence, assuming that the decision makers are male, as is typically the case.
By focusing exclusively on street criminals, delinquent gangs, and working class males who hang out in bars, researchers inadvertently convey the impression that violence is monopolized by lower-ranking, relatively powerless members of society. In fact, several chapters in Male Violence theorize as to why this particular pattern of violence should be expected. Yet even a cursory examination of our species' history, at least from the advanced horticultural period onward, indicates that it is typically the most powerful members of society who inflict the greatest levels of violence upon weaker competitors. The pre-Civil War system of slavery in the United States, the genocide of North American Indian populations, the German holocaust, and the ritualistic human sacrifices practiced in various pre-industrial societies provide good examples.
With the notable exception of Paul Gilbert's very excellent concluding chapter, few, if any, of the other papers directly address the more structural, institutionalized forms of male violence. Most of the contributors are psychologists, and their training would necessarily cause them to emphasize individual level phenomena. But their very important contributions must be supplemented by more structurally-oriented analyses.
The heavily individualist emphasis notwithstanding, John Archer's Male Violence makes an important contribution toward understanding both the evolutionary as well as the more proximate causes of male aggression and violence. It will be an invaluable reference for scholars studying these recurring problems.
Reviewed by EDWARD M. MILLER, Dept. of Economics and Finance, University
New Orleans, NEW ORLEANS, LA 70148, U.S.A.
Social Stratification and Socioeconomic Inequality: Vol. 2: Reproductive and
Interpersonal Aspects of Dominance and Status is the second volume of a two part work.
The first volume of the work, A Comparative Biosocial Analysis was published in
and will not be discussed here. The author, Dr. Ellis is professor of sociology at North
Dakota's Minot State University, and is a leader in the new area of biological sociology.
There isn't space to comment fully on all the book's essays, but an attempt will be made to
indicate the topics covered and their flavor.
The lead essay, by Wiederman and Allgeier, deals with male economic status and gender differences in mate selection preferences, and in particular with the well documented (with the documentation summarized here) tendency for males to care more about their partner's physical attractiveness, while females care about their mate's income. This could be the result of a woman's standard of living being determined by her choice of mate, and the female selecting her mate knowing this. Or, it could be the result of mechanisms built by eons of selection. The critical test is argued to be whether high income females (whose standard of living is not primarily determined by their husband's income) attach as much importance to a mate's income (or potential income) as poorer females. Evidence is presented from several surveys that even high income women (such as medical doctors) attach great importance to their husbands having an even higher income than they do.
The next essay, by Masters and Carlotti, studies reactions to video clips to discover how the sexes respond to political leaders.
Mazur presents a model of social stratification in which testosterone plays a reciprocal role, being elevated by the achievement of status, but also contributing to successful dominance seeking.
Kemper follows up with an essay on social stratification, testosterone, and male sexuality. He reviews the literature on copulatory frequency in males. Among younger males the lower-class ones have the higher copulatory frequencies. However, the pattern reverses among the older males where the higher classes have the higher copulatory frequencies. He argues that status attainment results in a testosterone surge which results in more sexual activity, and that as males age, such events become rare for lower class males, but more common for the upper class ones. The result is that the relative frequencies of sexual activity reverse with aging.
William James presents an essay on parental dominance/social status, hormone levels, and offspring's sex ratios. He proposes (with some supporting evidence) that parental dominance (status achievement) affect hormone levels (notably testosterone). This affects human sex ratio such that those that have achieved higher status are more likely to have male offspring.
Brammer, Raleigh, and McGurie report on the neurotransmitter serotonin's role in status attainment in vervet monkeys. What is known about serotonin in humans is reviewed. It is then reported that in 25 separate groups dominant male vervet monkeys had higher levels of whole blood serotonin. Experiments involving removal of dominant monkeys from groups showed that the dominant animals were not born with the higher serotonin levels, but acquired them about the time of acquiring dominance. Manipulations of serotonin levels via tryptophan or pharmaceuticals affected certain forms of behavior. Manipulations in non-dominant monkeys showed that raising serotonin levels contributed to acquiring dominance. Finally, a review of the literature on serotonin metabolites in human spinal fluid suggests a low level of serotonin release in the brain may be a marker for impulsive behavior.
Sachaser has a fascinating account of social dominance and health in non-human mammals, namely a case study in guinea pigs. Guinea pigs form themselves into stable social structures. The pituitary adrenocortical and sympathetic adrenomedullary systems are not activated in the process by which group living guinea pigs maintain their social structures. This seems to hold when group raised males are placed in a new cage with each other. However, when two males, each of whom has been reared only with a female and has never experienced the role of a subdominant individual, are placed together, aggressive encounters occur. Pituitary adrenocortical and sympathetic adrenomedullary hormone levels are elevated. When the males are not separated, one eventually dies, not due to wounds, but apparently due to a changed psychological state in the animals. Likewise, individually reared males placed in a large colony show a large increase in pituitary adrenocortical hormones and sometimes die, but the death is not related to actual social interactions. The possibility of something similar in humans is provocative.
Three of the chapters in the book are by Lee Ellis, the editor of this volume. One is a comprehensive review of social status and health in humans, the nature of the relationship and its possible causes. Ellis lists 165 studies dealing with this. All but four show that high status individuals are healthier. He examines various explanations for this effect, finding evidence for most of them. He presents evidence that the lifestyles of lower class individuals involve such risk factors as more smoking, drinking, reckless driving, and taking of few health precautions. While the relationship exists, evidence shows that these practices account for only a minor percentage of the total association between status and health. Just as the above mentioned guinea pig study shows that low status individuals experience more stress (including emotional stress), which affects their health, there is evidence that low status humans experience more hazards and greater stress. Evidence is presented that stress adversely affects human health.
The social structure explanation maintains that the poorer health is due to social institutions, notably worse medical care among the poor. There is little dispute that medical care is worse among the poor. However, evidence suggests that medical care makes a relatively small contribution to life expectancy. Also, the institution of universal health insurance in some industrialized countries does not seem to have reduced variability in health. While there is some evidence that poor health impairs economic success (the social selection hypothesis), the effect appears to be too weak to explain the observed correlation. Finally, Ellis proposes what he calls the biosocial selection hypothesis. This is that several interrelated genetically influenced variables may bring about the association between social status and health.
Another of Lee Ellis's massive data reviews deals with the relationship between height (or body size) and social status. Nearly one hundred studies were located on the body size and status relationship in non-human animals. Studies showed either a positive relationship (more frequent in males) or no relationship. Reports of a negative relationship are never found. Oddly enough at several points Ellis refers to the only explanation in the literature for the size status correlation being the nutritional one (such as p.108), although certainly the simple theory that size contributes to winning fights, and hence to achieving dominance, is an obvious one.
More fascinating are the human studies, where virtually all studies show a positive relationship. Many of these compare the children's height with their parents status, and may reflect better nutrition among the upper classes. While in non-humans, a positive relationship between status and height is found most often in males, in humans it is found in both sexes. Only 4 out of 160 findings failed to report a positive relationship.
However, for weight versus status the relationship is more complex. Recently in industrial societies there has been an inverse relationship, especially among women, reflecting greater lower class obesity. Ellis discusses the possibility that this may reflect class differences in diet. An alternative possibility is that in industrialized societies males prefer slim women as spouses, and females prefer high status males. Since Ellis reports that female status is usually measured by husband's occupation or status, the inverse correlation of status and weight may merely be documenting the operation of the marriage market. Of course, with obesity heavily influenced by genes, this characteristic of the marriage market implies that the genes for slimness will eventually come to be associated with those that lead to high status in males.
The final essay by Ellis offers a theoretical integration. He introduces the concept of r/K selection, proposing a biosocial theory in which certain genes and social factors encourage having a few children and investing heavily in them (K selection). Others do the opposite (the r strategy). While r/K theory has frequently been used to explain constellations of racial differences (Miller 1993, 1994, 1995, Rushton 1995), Ellis avoids this topic, although he does refer once (p. 160) to countries where the genes for altruism and intelligence are most prevalent.
He argues that height, birth weight, physical health, mental health, intelligence, brain size, and social status should be correlated. He provides a table of correlation studies showing that most of these have indeed been found to be correlated. Perhaps the most controversial of these relationships is the one between brain size and IQ. Ellis mentions the new MRI work showing this (Willerman et al. 1991), as well as other studies. A more recent literature review is by Rushton & Ankney (1996).
Ellis suggests that common genes may influence these relationships. A relationship he does not expound on is his documentation of a social class, birth weight relationship, which is usually attributed to better nutrition and prenatal care in the upper classes. A disproportionate part of a new born's weight is his brain, most brain growth appears to occur before birth, and adult intelligence and brain size are related. An obvious possibility is that certain genes are producing large brains at birth and hence high birth weights, large adult brains, high adult intelligence, and hence high adult social status. Supporting this hypothesis is the body of research in The Bell Curve (Herrnstein & Murray, 1994) showing how intelligence contributes to adult status and that intelligent women have babies with higher birth weights. There is the Jensen & Johnson (1994) evidence that children's head size is heritable, and their evidence that head size and childhood intelligence appear to be affected by the same genes, and the evidence that occupational status has a high degree of heritability (Ellis, 1993; Taubman, 1976). The essay concludes by arguing that today in industrial societies there is ongoing selection against intelligence and certain other desirable traits. As good as Ellis's discussion is here, a more recent and detailed discussion is by Lynn (1996, reviewed by Miller, 1997).
In summary, this book has ten excellent essays that should be of interest to those working on the biological (including genetic) aspects of social stratification. The essays are exceptionally well documented. The book has an incredible 67 pages of references, and a 21 page name index (and the usual subject index). Thus it should be exceptionally useful to those trying to find their way throughout the complex literature in this field, where medical, biological, and genetic works are as relevant as social sciences ones.
Ellis, Lee (1993). A biosocial theory of social stratification: An alternative to functional theory and conflict theory. In Ellis, Lee, Editor (1994). Social Stratification and Socioeconomic Inequality, Vol. 1: A comparative biosocial analysis. Westport: Praeger.
Herrnstein, R. J. & Murray, C. (1994). The Bell Curve: Intelligence and Class Structure in American Life. New York: The Free Press.
Jensen, A. R. & Johnson, F. W. (1994). Race and sex differences in head size and IQ. Intelligence, 18, 309-333.
Lynn, R. (1996). Dysgenics: Genetic Deterioration in Modern Population, Westport: Praeger.
Miller, E. M. (1993). Could r Selection Account for the African personality and life cycle. Personality and Individual Differences, 15, 665-676.
Miller, E. M. (1995). Environmental variability selects for large families only in special circumstances: Another objection to differential K theory, Personality and Individual Differences, 19 903-918.
Miller, E. M. (1997). Income, Intelligence, Social Class, and Fertility. Journal of Social, Political, and Economic Studies, 22 95-117.
Rushton, J. P. (1995). Race, Evolution and behavior: A life history perspective. New Brunswick: Transaction Publishers.
Rushton, J. P. & Ankney, C. D. (1996). Brain size and cognitive ability: Correlations with age, sex, social class, and race. Psychonomic Bulletin and Review, 3, 21-36.
Taubman, P. (1976). The determinant of earnings: Genetic, family and other environments; a study of male twins, American Economic Review, 66, 858-870.
Willerman, L., Schultz, R., Rutledge, J. N. & Bigler, E. D. (1991). In vivo brain size and intelligence. Intelligence, 15, 223-228.
Reviewed by GUY RICHARDS, 327, 666 Leg in Boot Square, Vancouver, B.C.
This book is one of a series aimed at the intelligent general reader. He or she is in for an
intellectually exciting, rough ride through evolutionary biology: typical Dawkins, and
Dawkins's 'digital river' flows through time, occasionally dividing ('speciating') into separate streams when some event isolates some individuals from the main population. Only the digital nature of DNA's four base codes can enable genes to transmit their information reliably over many centuries and generations. This process operates much as digital pulse code modulation brought back the first pictures of Mars and subsequently of other planets. (Incidentally, language is digital: were it analog, we would have to speak loudly of elephants and quietly of mice, which would be confusing at a distance.) All living things reproduce through the DNA-RNA system (with the exception of the prion agents responsible for scrapie in sheep and 'mad cow disease'). We are therefore all related. Sex mixes genes within species so that to trace ancestry for more than three or four generations is difficult. But this is not so between species. They have become separated into different 'rivers', and therefore shared traits between species do tell us about their ancestry.
'All Africa and Her Progenies' begins with a well aimed criticism of cultural relativism. Dawkins is more gentle than I would be. Having worked among sociologists, I am forever grateful to the common sense of Roger Trigg (University of Warwick philosopher, author of Reason and Commitment (1973)). He rescued me from the excesses of cultural relativism prevalent within sociology. Cultures are best seen as theories about the world, mental and physical tools, ways of handling the world, meme systems, and as such can be more-or-less compatible with human nature, more-or-less 'synergic' to use Ruth Benedict's word. Admittedly, as with all important tools, as we shape them, they shape us.
Sex mixes genes within species, but this only applies to nuclear genes. The mitochondria in the cytoplasm almost certainly derived from bacteria incorporated into the first eukaryotic cells, have their own DNA (incidentally, this applies also to the chloroplasts of plant cells). These are transmitted to the next generation in the abundant cytoplasm of the ovum only.
Harold Euler and Barbara Weitzel (1995, 1996) argue that, of our four grandparents, our maternal grandmother is likely to be the most solicitous, since she is the most certain that we do in fact carry her (nuclear) genes. She is also the only grandparent whose mitochondrial genes we carry.
This purely maternal transmission of mitochondrial DNA, and its molecular changes over time, enable analysts to theorize about the ancestry of present human groups. The most likely theory is that humans originated in Africa, approximately 200,000 years ago. African women show more DNA diversity than do women from the rest of the world, suggesting that all of us non-Africans are descended from one group of Africans, and all humans originally from one African woman, 'Mitochondrial Eve'.
'Doing Good by Stealth' attacks the creationist argument that complex organs such as the eye must have been created whole and in good working order at the outset. No, there are advantages from numerous incremental improvements for natural selection to work on, and plenty of time for this evolution to have occurred. In different species various kinds of eye have independently evolved - at least 40 times.
The evolution of the bee waggle dance presents some challenging but solvable puzzles. A widespread feature of insect nervous systems lies at the core of the puzzle. Many insects orient their movement to the direction of light. When there is no light, 'up' serves as the direction to angle from (i.e. as reference direction). The physical state of bees returning from a source of nectar becomes important information for the others in the hive. If they are tired and waggle slowly, this indicates a long flight. One can imagine that the physiological state of the returning bees has become refined and formalized by natural selection into unambiguous flight directions for their sisters in the hive.
Bees' eyes are sensitive to the plane of polarization of light which enables them to detect the position of the sun even on cloudy days. They can also see ultra-violet light. This has an obvious use: ultra-violet photographs of flowers reveal paths leading to nectar more clearly than do photographs in conventional light. Here is a remarkable instance of co-evolution of bees and flowers. Nectar- and pollen-laden bees returning from a flight are thus able to re-enact in their dance in the hive the direction of their find relative to the sun. If done on a vertical surface, up represents the sun's direction. Bees without hives are at a less sophisticated stage of evolution; they merely re-enact the direction of their flight on a horizontal surface.
Economists will translate the chapter 'God's Utility Function' as, what is nature maximizing? Those familiar with Dawkins's work will not be surprised to learn that his answer is DNA survival. Bob MacDonald presents a weekly popular science program for Canadian radio audiences ('Quirks and Quarks' on the Canadian Broadcasting Corporation). Near the end of an interview with Dawkins, he asked "is there some purpose to the universe?" Dawkins replied: "That question doesn't deserve an answer." The question gets similar terse treatment in this chapter.
This is an old philosophical question and, if only out of respect for its age, it deserves a more polite answer than Dawkins gives. An answer consistent with an evolutionary perspective would be that humans are purpose-seeking animals because it is adaptive to anticipate the future, especially the future behaviour of other animals. Events signifying human or intelligent agency merit our urgent attention, since they may pose great threat or sometimes great reward. We therefore tend to look for purpose and meaning where a physical explanation may suffice.
I still think 'why is there anything?' is a legitimate question, because we can conceive the opposite. Perhaps space-time is unstable without matter and energy. Why are there galaxies is a legitimate cosmology question. Admittedly, purpose, like justice, is a human concept which we should not expect to find in the inanimate world. But both concepts have evolved by natural selection, not only in us humans, but probably also in other big- brained mammals. If the concepts of purpose and justice have been produced by the universe, they presumably are adaptive to some species. Dawkins chooses a narrow meaning for 'why' which excludes physical explanation and leads him sounding rude. A little more philosophical humility please.
Old stars occasionally explode, go supernova. Ours has 'gone information'. Many steps, thresholds, lie between the evolution of replicating molecules and the information explosion which has resulted. Dawkins entertains us with three billion years of evolution condensed into 26 pages using galactic language which shuns perspective parochial to Earth. But, he is obliged to use life on Earth as the only example we know for sure to exist.
Successful genomes produce phenotypes which are in a sense good 'theories' about the environment. The latest hardware requires fast-acting nerve cells operating in parallel in brains which can compactly model their surroundings with information (that which forms or informs action) directly derived from the senses, rather than by the slow trial-and-error of natural selection. Knowledge, tools, learned skills - that is memes - have become as important as genes.
By radio and space probe, this information has begun to spill out of our solar system and may eventually infect other star systems. Why haven't we heard from other worlds? Maybe stars with life-bearing planets lie in a zone around the edge of the galaxy (because there is too much radiation at the center to support life) and we are all at about the same stage of evolution.
Intelligent readers coming fresh to Dawkins may find his choice of subjects and the way he links them confusing. But they will enjoy being rafted over the digital rapids, even if the ride is a bit bumpy.
Euler, Harold & Barbara Weitzel. 1995. 'Grandparental care and intergenerational relationships reflect reproductive strategies.' paper presented at annual meeting of European Sociobiological Society, Cambridge.
Euler, Harold & Barbara Weitzel. 'Discriminative grandparental solicitude as reproductive strategy.' Human Nature. 7:39-60.
Trigg, Roger. 1973. Reason and Commitment. Cambridge: Cambridge University Press.
by GUY RICHARDS, 327, 666 Leg in Boot Square, Vancouver, B.C. V5Z 4B3,
This book is illustrated with elegant and informative simplicity by Mary Krikorian.
Margie Prophet's thesis is also simple: pregnancy nausea is adaptive, in that it helps to protect the 'embryo' in the 1st trimester, the period of organ formation. She reserves 'fetus' for the 2nd and 3rd trimesters.
Her book can be profitably read and enjoyed by anyone, but it is especially for women planning pregnancy, experiencing pregnancy or already mothers, for their mates, their doctors and other maternity care providers.
9 Lunar Months Human pregnancy lasts 9 months, but it is commonly measured from the date of last menstrual period (LMP) from which there is a conveniently remembered time of forty weeks to the expected date of delivery (EDD). However as Profet points out the last menstrual period predates pregnancy by 2 weeks, the time of the last ovulation and therefore of conception. Pregnancy therefore averages 38 weeks from conception or 266 days. She calls this 8 1/2 months, but that would be 31 day months. It is in fact 9 synodic lunar months (full moon to full moon, 29.53 days x 9 = 265.77 days) which suggests an interesting speculation. If births tend to cluster around full moon, as maternity wards suspect, then ovulations must also have clustered around full moon. Menaker (1967) found among a million births in New York a 1% preponderance in the week before and the week after full moon. Tropical moonlight might engender a more definite result.
Natural Toxins And The Body's Response Our senses of taste and smell have been largely selected to respond to substances met during our long contact with the natural world. They may, but we cannot expect them to, warn us about synthetic poisons. Pungent odours and bitter or sour tastes warn us of plant toxins, or of spoiled food in which bacteria have grown. On the other hand the sweet taste of ripe fruit and honey attracts us, signifying a valuable source of energy. Most strong tasting foods such as pepper and other spices contain toxins. Even the plants we commonly eat and call 'vegetables' contain some toxins, hence it is wise to eat a diversity of foods and not rely on any one.
Teratogens are toxins which cause malformations or birth defects (translates literally as 'monster forming substances'). The embryo in the first trimester is especially vulnerable to toxins so that doses, which would not harm a fetus, a child or an adult, may disrupt organ formation. Cleft lip, heart abnormalities, neural tube defects (nervous system defects), even death of the embryo may result. Some have estimated that 60 to 70% of conceptions suffer some damage sufficing to cause spontaneous abortion. It is the uterus's form of quality control, probably an immune reaction to abnormal proteins, and less exacting with advancing maternal age. Natural selection begins in utero. Estrogens enhance olfaction (the sense of smell). Women usually have a better sense of smell than men, but this is especially so in the first 3 months of pregnancy, when a woman's body is flooded with hormones from the embryo's placenta. The placenta thus plays an active part in gaining nourishment from mother's blood and in defending the embryo's interests by manipulating her body and diet. Estrogens and progesterone not only enhance olfaction, they also increase the sensitivity of the chemoreceptor trigger zone (CTZ) in the brain stem to traces of toxin in the blood. The CTZ responds by inducing nausea and with sufficient stimulus, vomiting.
Aversion and nausea from strong tasting foods is often the first sign of pregnancy, even before the first missed period. In fact it may be a more reliable guide, since at the time of the expected menstruation there is some bleeding caused by nidation (nesting) of the embryo into the lining of the womb. The seemingly innocuous potato is a comparatively recent addition to human diet, derived from a highly toxic wild ancestor native to the Andes. Its toxins are eliminated unusually slowly, so that if a pregnancy is planned they should be forgone for about a month before conceiving. The sprouts and green parts are especially toxic and suspected of causing neural tube defects.
Why Are There Plant Toxins? Plant leaves contain toxins to dissuade animals, chiefly insects, from eating them. It would be more accurate to say that co-evolution between plants and animals has resulted in mutual manipulation. Plants, unable to flee, have developed chemical defences against herbivores and parasites. Animals have developed detoxifying enzymes and other mechanisms enabling them to cope with a certain dose of certain toxins which determines what they can and cannot eat. Humans have cultivated some plants because experience has shown they are less toxic than most, but in selecting them for low toxicity we make them palatable to insects too. Conversely the 'organic' effort to avoid the use of pesticides, by selecting for insect-resistant strains, runs the risk of reintroducing toxicity for human embryos.
Angiosperms, flowering plants, manipulate animals with their flowers and fruit, to spread their pollen and their seeds. Scents, flowers and nectar attract pollinators. Bright colours, sugar and lowered toxicity signal ripe fruit whose seeds are ready to be spread via the gut of hungry birds and mammals. Ripe fruit, the means of spreading plant embryos (seeds), is thus safe food for human embryos. Toxins can be absorbed through the skin by brushing against highly toxic leaves such as poison ivy, and stinging nettles, through infected cuts, and from inhaling vapours from strong smelling food such as onions. Nausea is a highly probable response during the first 3 months of pregnancy. So Mum-to-be should not be expected to cook such foods and her mate should accommodate his own diet to her needs.
Humans are not good pollinators, so why do we enjoy flowers and their scents? Perhaps a flowering tree or bush provides a pleasant memory prompting a return to the same site later when the fruit is ripe. Scents are pheromones and powerful stimulators of nostalgia for places past visited.
Other Toxins And Poisons Profet suggests we reserve the word 'toxin' for natural poisons. Bacterial toxins may arise by infection of the body or of food. Some will arise as a result of fermentation of the infected food. Ethyl alcohol is one of the less toxic of such products. Profet regards it as a synthetic toxin not met by our hunter-gathering ancestors. I would have thought it must have been with us, from accidental and then deliberate fermentation, for a very long time, so that it is surprising that is has no warning taste. A witty advertisement for a brand of vodka, 'Prince Igor has no taste!' reminds us of the fact, but alcohol is bad for embryos and fetuses.
Some vitamins surprisingly are toxic in large doses. The Inuit have long known that the livers of polar bears and arctic foxes are poisonous. They are so because of their high content of fat soluble vitamins A, D, E and K. Synthetic analogs of vitamin A are very teratogenic. Sadly tea, coffee and chocolate contain toxins whose bitter taste may be masked by sugar and cream, but not their toxic effects.
Many synthetic drugs are teratogenic in prescribed doses. They are commonly given in capsules or injections which bypass the warning sense of taste. But they will not always taste 'toxic', since they have not been part of our ancestral experience. Thalidomide is a useful sedative drug for old men, but sadly it is also good at relieving pregnancy nausea, since it is highly teratogenic. It caused limb defects in 1/3 of exposed fetuses when it was used in Europe and Canada for a short time about 1960.
Many synthetic drugs are now known to be teratogenic, for example disulfiram ('antabuse'), used to dissuade alcoholics from drinking alcohol; lithium, used in psychiatry to treat manic depressive disorders; diethylstilbestrol, exposed female embryos are liable to vaginal cancer in adult life; methotrexate and the other drugs used in treatment of cancer.
A few substances which relieve pregnancy nausea are almost certainly harmless in themselves at the dosage prescribed, except in that it may be unwise to allay the warning effect of nausea. Vitamin B6 or pyridoxine and cyclizine compounds ('Bendectin', 'Marzine') had long been used without mishap, but after the thalidomide tragedy no-one dares prescribe them to young women. As Profet says they have become 'litogens' (substances which create litigation).
Pregnancy is a good time to stop smoking: him too. It exposes the embryo to benzopyrine and other mutagens liable to damage DNA. She will wisely be averse to, and nauseated by, others smoking near her. A danger is that if she smokes too her sense of smell will be blunted. Sperm DNA is also liable to damage from mutagens - an extra reason for him to stop smoking.
Teratogenic Infections Infections may damage the embryo directly by the virus or bacterium infecting it or its placenta, or by producing toxins in the mother's blood which enter the embryo via the placenta, or by inducing a fever in the mother. Prolonged high temperature, such as from a sauna is bad for embryos. Rubella (German measles) is a mild viral disease in children or adults, but serious in embryos in which it may cause deafness, mental impairment and other birth defects. In planning a pregnancy it's important to make sure one is immune to rubella, either from having had it or from a vaccine. The earlier in pregnancy maternal infection occurs the more probable and serious the damage. Infection in the first trimester (when 30-50% incur some damage) would justify termination of the pregnancy.
Genital herpes virus, chicken pox virus and cytomegalovirus are also liable to cause serious damage to embryos. Indeed even the common cold has been estimated to increase the risk of neural tube defects.
Toxoplasmosis is a protozoan disease common in cats, which can harm human embryos and fetuses. Profet writes 2 informative pages on it, but forgets to mention that it is caused by a protozoon. Someone else should handle the litter box.
Syphilis is a well known example of a sexually transmitted bacterial disease injurious to more than 50% of embryos and fetuses of infected women. Penicillin will usually cure mother and the fetus, but it will not restore damaged organs.
In general the brain remains vulnerable longer than other organs, so that it may be damaged by infections later in pregnancy or even in childhood and adult life. Embryos are vulnerable to any mutagen such as x-rays, excess ultra-violet light, drugs used in treating cancer, smoking.
Spermatogenesis is also vulnerable to mutagens. The DNA damage is diminished by vitamin C. It takes a little less than 3 months to produce a new generation of sperm, so an intending father should stop smoking at least 3 months before conception and take 250 mg of vitamin C per day.
Pregnancy sickness is not psychogenic nor cultural. Women the world over experience it. It coincides with the vulnerable period of organ formation in the embryo, the first 3 months of pregnancy. After that it abates, when there is a need for extra nourishment in the 2nd and 3rd trimesters.
Prenatal Tests And Termination Profet deals carefully with the complicated subject of prenatal tests and when a woman might want to terminate her pregnancy. Many women regard an attack of rubella in the first trimester an indication for termination without any further test.
Pregnancy nausea is not a perfect protection against teratogens, nor can it protect against genetic and chromosomal abnormalities such as Down's Syndrome. An ultrasound image (Sonogram) can reveal structural abnormalities such as neural tube defects and heart abnormalities in the second trimester, and of course, later. Amniocentesis (aspiration through a needle of some fluid from the amnion surrounding the fetus) may be needed to diagnose Down's syndrome and neural tube defects. Chorionic villus sampling (CVS) consists of taking a small sample of placental, therefore embryonic, cells for a culture and genetic analysis. CVS has the advantage that it can be done at 10 weeks gestation and can therefore make possible a first trimester termination if indicated. But invasive tests of this kind carry a small risk to the embryo or fetus and therefore should not be done unless the woman is willing to abort an abnormal pregnancy.
Profet has written her book so that each of its 12 chapters can be read separately and intelligibly, but this leads to a good deal of repetition. It also gives the impression that it is surprising that anyone is born normal. One could wish for more definite evidence of her principle thesis-the protective role of pregnancy nausea-but it's inevitable that this evidence can only accumulate slowly with careful attention to women's dietary and clinical history. Any couple planning reproduction will find this book rewarding.
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