Evolutionary science is indispensable for understanding biological processes. Effective medical treatment must be anchored in sound biology. However, currently the insights available from evolutionary science are not adequately incorporated in either pre-medical or medical school curricula. To illuminate how evolution may be helpful in these areas, examples in which the insights of evolutionary science are already improving medical treatment and ways in which evolutionary reasoning can be practiced in the context of medicine are provided. To facilitate the learning of evolutionary principles, concepts derived from evolutionary science that medical students and professionals should understand are outlined. These concepts are designed to be authoritative and at the same time easily accessible for anyone with the general biological knowledge of a first-year medical student. Thus, we conclude that medical practice informed by evolutionary principles will be more effective and lead to better patient outcomes. Furthermore, it is argued that evolutionary medicine complements general medical training because it provides an additional means by which medical students can practice the critical thinking skills that will be important in their future practice. We argue that core concepts from evolutionary science have the potential to improve critical thinking and facilitate more effective learning in medical training.

Indigenous populations are generally reported to suffer greater active tuberculosis (TB) disease burden. The objective of this study was to examine ecological associations between cases of active adult and pediatric TB reported from 2002 to 2004 and community characteristics in indigenous communities of the Paraguayan Chaco. Adult and pediatric models were examined by negative binomial and Poisson GLM regression, respectively. Active TB prevalence in indigenous people was eight times higher than the nonindigenous population. Communities with a health post were more than twice as likely to report active adult TB (RR = 2.07, 95% confidence interval (CI) [1.14–3.83], and p < 0.05). Each additional average year of education in the community was associated with nearly 50% less likelihood of active pediatric TB (RR = 0.53, 95% CI [0.38–0.73], and p < 0.001). Although nonsignificant, the presence of nonindigenous community members had a strong protective association in both the adult (RR = 0.56, 95% CI [0.30–1.03], and p = 0.6) and pediatric models (RR = 0.64, 95% CI [0.34–1.14], and p = 0.14). These results reinforce the importance of increasing epidemiologic surveillance and investigating the social determinants of TB disease among vulnerable indigenous populations.

Evolutionary science is indispensable for understanding biological processes. Effective medical treatment must be anchored in sound biology. However, currently the insights available from evolutionary science are not adequately incorporated in either pre-medical or medical school curricula. To illuminate how evolution may be helpful in these areas, examples in which the insights of evolutionary science are already improving medical treatment and ways in which evolutionary reasoning can be practiced in the context of medicine are provided. To facilitate the learning of evolutionary principles, concepts derived from evolutionary science that medical students and professionals should understand are outlined. These concepts are designed to be authoritative and at the same time easily accessible for anyone with the general biological knowledge of a first-year medical student. Thus, we conclude that medical practice informed by evolutionary principles will be more effective and lead to better patient outcomes. Furthermore, it is argued that evolutionary medicine complements general medical training because it provides an additional means by which medical students can practice the critical thinking skills that will be important in their future practice. We argue that core concepts from evolutionary science have the potential to improve critical thinking and facilitate more effective learning in medical training.

The current study assessed the heritability of personality in a traditional natural-fertility population, the Ache of eastern Paraguay. Self-reports (n = 110) and other-reports (n = 66) on the commonly used Big Five Personality Inventory (i.e., extraversion, agreeableness, conscientiousness, neuroticism, openness) were collected. Self-reports did not support the Five Factor Model developed with Western samples, and did not correlate with other-reports for three of the five measured personality factors. Heritability was assessed using factors that were consistent across self- and other-reports and factors assessed using other-reports that showed reliabilities similar to those found in Western samples. Analyses of these items in combination with a multi-generation pedigree (n = 2,132) revealed heritability estimates similar to those found in most Western samples, although we were not able to separately estimate the influence of the common environment on these traits. We also assessed relations between personality and reproductive success (RS), allowing for a test of several mechanisms that might be maintaining heritable variation in personality. Phenotypic analyses, based largely on other-reports, revealed that extraverted men had higher RS than other men, but no other dimensions of personality predicted RS in either sex. Mothers with more agreeable children had more children, and parents mated assortatively on personality. Of the evolutionary processes proposed to maintain variation in personality, assortative mating, selective neutrality, and temporal variation in selection pressures received the most support. However, the current study does not rule out other processes affecting the evolution and maintenance of individual differences in human personality.

Hypotheses on the benefits of the practice of partible paternity are tested using demographic data for Ache foragers of Paraguay. Partible paternity refers to the institution of multiple males considered to contribute to the conception of a single offspring. Analyses focus on patterns of primary and secondary co-fatherhood among men, genealogical relationships between co-fathers, and relation between band co-residence and co-fatherhood. Results indicate that men who had more secondary fatherhood also had more primary fatherhood; co-fathers are more closely related, on average, than men who are not co-fathers; and co-fathers were also more likely to reside together than men who were not co-fathers, even after controlling for relatedness. Results are most consistent with women choosing co-fathers of offspring in ways that maximize likelihood and amount of investment (multiple investors hypothesis) and men competing for more mates with at least partially affiliative outcomes (mate competition and male alliance hypotheses).

Our species exhibits spectacular success due to cumulative culture. While cognitive evolution of social learning mechanisms may be partially responsible for adaptive human culture, features of early human social structure may also play a role by increasing the number potential models from which to learn innovations. We present interview data on interactions between same-sex adult dyads of Ache and Hadza hunter-gatherers living in multiple distinct residential bands (20 Ache bands; 42 Hadza bands; 1201 dyads) throughout a tribal home range. Results show high probabilities (5%–29% per year) of cultural and cooperative interactions between randomly chosen adults. Multiple regression suggests that ritual relationships increase interaction rates more than kinship, and that affinal kin interact more often than dyads with no relationship. These may be important features of human sociality. Finally, yearly interaction rates along with survival data allow us to estimate expected lifetime partners for a variety of social activities, and compare those to chimpanzees. Hadza and Ache men are estimated to observe over 300 men making tools in a lifetime, whereas male chimpanzees interact with only about 20 other males in a lifetime. High intergroup interaction rates in ancestral humans may have promoted the evolution of cumulative culture.