In most primate groups emigration of the maturing young of one or the other sex tends to serve as an incest avoidance mechanism. Among most primate species it is the males who change groups. This supports the theory that, in terms of reproductive success, males should compete for mates and females should compete for resources. In hominoids the combination of increased longevity and greater female discrimination in mate selection seems responsible for female emigration. This may relate to the high frequency of patrilocality and male control of resources among human groups.
American Journal of Human Biology: The Official Journal of the Human Biology Council
The grandmother hypothesis (GH) of Hawkes et al. (: Proc Natl Acad Sci USA 95: 1336-1339) finds that selection for lower adult mortality and greater longevity allow for the evolution of prolonged growth in human beings. In contrast, other researchers propose that the evolution of the human childhood and adolescent stages of life history prolonged the growth period and allowed for greater biological resilience and longevity compared with apes. In this article, the GH model is reanalyzed using new values for some of its key variables.
Evolutionary medicine acknowledges that many chronic degenerative diseases result from conflicts between our rapidly changing environment, our dietary habits included, and our genome, which has remained virtually unchanged since the Palaeolithic era. Reconstruction of the diet before the Agricultural and Industrial Revolutions is therefore indicated, but hampered by the ongoing debate on our ancestors' ecological niche.
OBJECTIVE: The author examined the chromosomal linkage method as an approach to the genetic basis of schizophrenia and bipolar disorder. METHOD: Comparisons were conducted of recent meta-analyses of genome scans of schizophrenia and bipolar disorder and of the three largest (N>300) sibling pair studies of schizophrenia and schizoaffective disorder and a comparable study of bipolar illness. RESULTS: Recent meta-analyses have not identified consistent sites of linkage.
OBJECTIVE: To achieve a unified concept of the aetiology of psychosis. BACKGROUND: The nuclear symptoms of "schizophrenia" occur with approximately the same age- and sex-specific incidence in all human populations. No substantive environmental precipitant has been identified, and yet these "illnesses" are associated with deviations in brain structure that are uniform across populations, are established late in development and relate to the capacity for language. No genes have been identified by linkage or association strategies.
When a couple become erotically pair-bonded, whether for a night or a lifetime, they are by definition committed to each other erotically. That is the minimum. The degree varies. The commitment may be limited to the proceptive phase of solicitation or courtship, or it may include the acceptive phase of coitus, or it may extend to the conceptive phase of parenthood. People "fall in love with their fantasy" and project onto the partner a range of future commitments.
Emlen's (1995) paper "An evolutionary theory of the family" reviewed existing ideas about the nature of family systems and the reasons why they have evolved in certain animal species. His theorizing led him to propose 15 predictions about how family systems function, based on favorable evidence from various species, mostly birds. While he suggested that these predictions can be applied to the human case, he himself did not attempt to do so.
Psychopathology, mental illness, and psychiatric treatment are concepts relevant to modern medicine and medical psychology and replete with cumbersome intellectual and literary baggage. They bear the imprint of suppositions, world views, and general beliefs and values exemplified in the science, history, and general culture of Anglo European societies.
The current review aims to unify existing views of altruism through an examination of the biological bases of a fundamental form of giving: altruistic responding. Altruistic responding is most salient during heroic acts of helping but is also observed any time one perceives another's distress or need, which in turn motivates one to help at a current cost to the self. Such aid is simple, observable across species, and rooted in the instincts and circuits that evolved to maximize inclusive fitness through the care of helpless offspring.