An evolutionary analysis of psychological pain following rape:: II. The effects of stranger,friend, and family-member offenders

In earlier papers we discussed a hypothesis for the evolutionary significance of psychological pain. In the present paper we discuss briefly the hypothesis and its application to the psychological pain experienced by rape victims. We have hypothesized that psychological pain reflects a psychological adaptation that is designed to focus on individual's full attention on fitness-reducing social circumstances, allowing correction of the pain causing events and their future avoidance. Psychological pain following rape is proposed to accomplish a focus of victims' attention on the fitness reducing circumstances of rape. Using a data-set comprised of 790 rape victims in the U.S. whose post-rape psychological trauma was assessed, we evaluate the effects of rape by strangers, friends and family members. The victims in the sample are most likely to be raped by strangers; this is especially the case for women as opposed to prereproductive-aged girls. Prereproductive-aged girls were more likely to be raped by family members than were women. Rape by strangers is the most psychologically traumatizing of the three rape-offender categories and family-member rape the least. The importance of victim's age and marital status as predictive factors in the degree of psychological trauma following rape—with reproductive-aged and married victims showing significantly more trauma than pre- or post-reproductive-aged and unmarried victims (see N.W. Thornhill and R. Thornhill 1990)—is not confounded by the type of rape perpetrator.     

The marital balance of power and quid pro quo: An evolutionary perspective

Although the marital therapy literature recognizes the importance of quid quo in marital negotiations, there has been little attention to certain important sources of power for men and women in that process. This paper will show how parental investment, certainty of paternity, patterns of mate preference, intrasexual competition, and reproductive status all affect the bergaining positions of men and women. Both premarital and marital negotiations will be discussed. Put into a developmental perspective, this will help clarify what is at stake in the common sources of conflict between the sexes. These considerations form a central part of the socioecology of marriage.     

The arts and human nature: evolutionary aesthetics and the evolutionary status of art behaviours

This essay reviews one of the most recent books in a trend of new publications proffering evolutionary theorising about aesthetics and the arts—themes within an increasing literature on aspects of human life and human nature in terms of evolutionary theory. Stephen Davies’ The Artful Species links some of our aesthetic sensibilities with our evolved human nature and critically surveys the interdisciplinary debate regarding the evolutionary status of the arts. Davies’ engaging and accessible writing succeeds in demonstrating the maturity and scope of the field and his critique is timely and unparalleled. A laudable effort, however it may have benefited from espousing a co-evolutionary model more explicitly. Moreover there may be reason to question the usefulness of the standard set of distinctions (‘adaptation’, ‘spandrel’, ‘technology’) that Davies appeals to.     

An analysis of the influence of age and school-attendance status on the spread of variola minor.

Definitions are proposed for the independent and joint contributions that the chemical groups A and B make to the free energy of association of the ligand A?B with a receptor. The definitions are independent of the choice of the standard state and are consistent with the basic thermodynamic cycle relating the association of the ligands A?B, A?Y and X?B to the receptor Rappaport 1976. The basic idea is the use of the excess free energy of association of the ligand A?Y over the free energy of association of the reference ligand X?Y as the measure of the “independent” contribution of the group A to the binding. This definition allows the free energy of association of the ligand A?B to be written as the sum of the independent contributions of the groups A and B, their joint contribution, and an invariant free energy of association of the reference ligand with any receptor. With the appropriate definition of the receptor-reference ligand complex, water can be chosen as the reference ligand. Using ΔG(A?OH)?AG(HOH), ΔG(H?B?H)?ΔG(HOH) and ΔG(HO?C)?ΔG(HOH) as the definitions of the “independent” contributions of the chemical groups A, B and C to the binding of the ligand A?B?C, the joint contribution of the groups A and C to the binding is ΔG(A?B?C) ? ΔG(A?B?H) ? ΔG(H-B-C) + ΔG(H?B?H).     

Fear and fitness: An evolutionary analysis of anxiety disorders

This article reviews the evolutionary origins and functions of the capacity for anxiety, and relevant clinical and research issues. Normal anxiety is an emotion that helps organisms defend against a wide variety of threats. There is a general capacity for normal defensive arousal, and subtypes of normal anxiety protect against particular kinds of threats. These normal subtypes correspond somewhat to mild forms of various anxiety disorders. Anxiety disorders arise from dysregulation of normal defensive responses, raising the possibility of a hypophobic disorder (too little anxiety). If a drug were discovered that abolished all defensive anxiety, it could do harm as well as good. Factors that have shaped anxiety-regulation mechanisms can explain prepotent and prepared tendencies to associate anxiety more quickly with certain cues than with others. These tendencies lead to excess fear of largely archaic dangers, like snakes, and too little fear of new threats, like cars. An understanding of the evolutionary origins, functions, and mechanisms of anxiety suggests new questions about anxiety disorders.     

The effects of age, season and fertility status on plasma and intratesticular insulin-like growth factor I concentration in stallions

The purposes of this study were to establish the basal plasma and testicular insulin-like growth factor-I (IGF-I) values for stallions ranging in age from 6 months to 23 years and to determine if IGF-I could be used as a marker for declining fertility. Blood and testes were obtained from 28 light horse stallions and colts. Of the 28 stallions, 22 were considered fertile and were categorized by age (<2 y, 5 to 10 y, 11 to 15 y, and 16 to 23 y); 12 age-matched stallions were grouped as to fertility status (fertile, subfertile, infertile); and all 28 stallions were grouped as to season of castration (breeding season vs. non-breeding season). In colts less than 2 years of age, IGF-I concentrations in plasma and testicular extracts were higher (P < 0.01) than in the other age groups and were higher in the breeding season than in the non-breeding season (P < 0.01). No significant differences in plasma or testicular extract concentrations of IGF-I were found among fertility groups. The results of this study demonstrate that plasma and testicular IGF-I levels are high in stallions younger than 2 years of age and then decline and plateau in stallions older than 5 years of age, suggesting that IGF-I may be involved in testicular development. The results allude to a possible seasonal effect on IGF-I production. However, it is difficult to separate true seasonality and the effect of age as only those stallions less than 2 years old exhibited variation between seasons. The IGF-I does not appear to have a direct relationship with declined fertility in the stallions tested, suggesting that IGF-I may not be a reliable biomarker for the diagnosis of subfertility and infertility.     

Socioeconomic status, marital status and childlessness in men and women: an analysis of census data from six countries

This study compares the effects of two distinct forms of human capital - income and education - on marital status and childlessness separately by sex in six different countries. Nearly 10 million individual records on individuals aged 16 to 50 were used from censuses from Brazil, Mexico, Panama, South Africa, USA and Venezuela dating from 2000 or later, to analyse the relationship between education, income and marital status and childlessness in men and women. Regarding income, the findings for both outcome variables are strongly consistent across all six countries. Highest-income males and lower-income females have the highest proportion of ever-married and the lowest proportion of childlessness (using a proxy for childlessness: own children in the household or not). There is no corresponding consistency of findings as regards education either between the sexes or among the countries. To conclude, a lower percentage of low-income men are selected by females, because for women male status and resources provided by men are important criteria in mate selection. Therefore a higher proportion of low-income men remain unmarried and childless. Thus selection seems to play a role in modern societies.     

Spontaneous reactivation of acetylcholinesterase following organophosphate inhibition. I. An analysis of anomalous reactivation kinetics.

The first kinetic studies on the spontaneous reactivation of Sarin-inhibited acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) are reported. With increasing pH the extent of reactivation increases while the observed rate constant decreases. An analysis of the change in aging rate constant as a function of pH suggests that the aging of alkyl-alkoxy phosphonylated acetylcholinesterases is not solely acid catalyzed.     

The reality and evolutionary significance of human psychological sex differences

The aims of this article are: (i) to provide a quantitative overview of sex differences in human psychological attributes; and (ii) to consider evidence for their possible evolutionary origins. Sex differences were identified from a systematic literature search of meta‐analyses and large‐sample studies. These were organized in terms of evolutionary significance as follows: (i) characteristics arising from inter‐male competition (within‐sex aggression; impulsiveness and sensation‐seeking; fearfulness; visuospatial and object‐location memory; object‐centred orientations); (ii) those concerning social relations that are likely to have arisen from women's adaptations for small‐group interactions and men's for larger co‐operative groups (person‐centred orientation and social skills; language; depression and anxiety); (iii) those arising from female choice (sexuality; mate choice; sexual conflict). There were sex differences in all categories, whose magnitudes ranged from (i) small (object location memory; negative emotions), to (ii) medium (mental rotation; anxiety disorders; impulsivity; sex drive; interest in casual sex), to (iii) large (social interests and abilities; sociosexuality); and (iv) very large (escalated aggression; systemizing; sexual violence). Evolutionary explanations were evaluated according to whether: (i) similar differences occur in other mammals; (ii) there is cross‐cultural consistency; (iii) the origin was early in life or at puberty; (iv) there was evidence for hormonal influences; and (v), where possible, whether there was evidence for evolutionarily derived design features. The evidence was positive for most features in most categories, suggesting evolutionary origins for a broad range of sex differences. Attributes for which there was no sex difference are also noted. Within‐sex variations are discussed as limitations to the emphasis on sex differences.     

Regulation of arterial metabolism I. The effects of age and hormonal status upon the utilization of glucose in vitro by rat aorta

1.

1. The effects of age and of the hormones epinephrine, hydrocortisone, insulin and estradiol upon the patterns of glucose metabolism of rat aorta in vitro were determined. Changes in the following parameters were evaluated: the glycogen and acid mucopolysaccharides content of the tissue; the amounts of glucose utilized and lactate produced; and the fraction of uniformly labeled [14C]glucose incorporated into lactate, lipids, glycogen, acid mucopolysaccharide and CO₂. Comparisons have been based upon the DNA content of the tissue.     

The fitness functions associated with diapause induction in arthropods I. The effects of age structure

This paper analyzes the effects of age structure on the shape of the fitness functions associated with diapause induction in arthropods and presents the following results: (1) The shape of the fitness function depends on three variables: age structure (specifically the time course of individuals passing through the end of the sensitive period), the position of the optimal time to switch to diapause, and the end of the season. (2) An optimal switching time that occurs soon after a sharp increase in the number of individuals passing through the end of the sensitive period causes the most distinct optimum. (3) Early emergence from diapause (assuming a suitable environment) increases fitness, but neither the mean nor the variance of the distribution of emergence times affects the position of the optimal switching time. (4) Net fecundity, acting through the age distribution, can greatly influence the shape of the fitness function. (5) Populations with fecundity schedules of short duration relative to the length of the juvenile phase are likely to have fitness functions with plateaus and no distinct optimum, depending on the relationship between temporal changes in age structure and the predicted position of the optimum. The width of such plateaus diminishes as the variance of the emergence distribution increases.     

Interaction of marital status and genetic risk for symptoms of depression.

Depression scores (DSSI) were available for 1232 MZ and 751 DZ female twin pairs who completed a mailed questionnaire. Pairs were divided into those concordant for being in a marriage-like state, concordant for having no partners, and those discordant. The pattern of twin correlations differed according to marital status. Our results suggest that having a marriage-like relationship acts as a protective factor in reducing the impact of inherited liability to symptoms of depression in the general population.     

The human Y chromosome: an evolutionary marker comes of age

Until recently, the Y chromosome seemed to fulfil the role of juvenile delinquent among human chromosomes--rich in junk, poor in useful attributes, reluctant to socialize with its neighbours and with an inescapable tendency to degenerate. The availability of the near-complete chromosome sequence, plus many new polymorphisms, a highly resolved phylogeny and insights into its mutation processes, now provide new avenues for investigating human evolution. Y-chromosome research is growing up.     

Guineafowl hind limb function. I: Cineradiographic analysis and speed effects

Avian striding bipedalism was studied in the helmeted guineafowl, Numida meleagris. High‐speed cineradiographs, light films, and videos were used to record hind limb movements across a wide range of speeds. In particular, direct visualization of the skeleton in X‐ray images allowed changes in pelvic and femoral position to be quantified with great accuracy for the first time. With the exception of limb protraction angle, all stride parameters are speed‐dependent. During the stance phase, guineafowl primarily employ knee flexion at very low speeds. At higher speeds, the magnitudes of hip and knee extension in the second half of stance progressively increase. Pelvic rotations are relatively small, but birds gradually pitch further forward with speed. An aerial phase is not present at speeds less than 2.0 m/sec, but discontinuities in the relationship of some parameters to speed indicate a gait transition near 0.9 m/sec. Birds are considered to be flying theropod dinosaurs, making characterization of bipedalism in living birds essential to understanding the evolution of theropod locomotion. Data from guineafowl, including the kinematic effects of speed, are informative about several aspects of locomotion in extinct theropods. However, many details of avian bipedalism evolved only within a subset of Theropoda, and are therefore not directly applicable to all members of the clade. J. Morphol. 240:115–125, 1999. © 1999 Wiley‐Liss, Inc.     

An inquiry into the evolutionary status and apparent identity of San hunter-gatherers

An attempt is made to reconcile a popular view of the Bushmen or San of southern Africa with reality. Following an analysis of the assumed relationships of living hunter-gatherers with their Pleistocene forebears and modem neighbors, the identity of the San is explored using archaeological and historical evidence. Finally an alternative view of modern San, consistent with this evidence, is proposed.     

The toad fly Lucilia bufonivora: its evolutionary status and molecular identification

The blow fly genus Lucilia is composed largely of saprophages and facultative myasis agents, including the economically important species Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae) and Lucilia sericata (Meigen). Only one species is generally recognized as an obligate agent of myiasis, Lucilia bufonivora Moniez, and this is an obligate parasite of toads. Lucilia silvarum (Meigen), a sister species, behaves mainly as a carrion breeder; however, it has also been reported as a facultative parasite of amphibians. Morphologically, these species are almost identical, and historically this has led to misidentification, taxonomic ambiguity and a paucity of studies of L. bufonivora. In this study, dipterous larvae were analysed from toad myiasis cases from the U.K., The Netherlands and Switzerland, together with adult specimens of fly species implicated in amphibian parasitism: L. bufonivora, L. silvarum and Lucilia elongata Shannon (from North America). Partial sequences of two genes, cox1 and ef1α, were amplified. Seven additional blow fly species were analysed as outgroups. Bayesian inference trees of cox1, ef1α and a combined‐gene dataset were constructed. All larvae isolated from toads were identified as L. bufonivora and no specimens of L. silvarum were implicated in amphibian myiasis. This study confirms L. silvarum and L. bufonivora as distinct sister species and provides unambiguous molecular identification of L. bufonivora.