Asceticism in Human Evolution

It is tempting to believe that humans, owing to their technological prowess, have elevated themselves above the laws of biology and escaped natural selection. Indeed, some think that humans have stopped evolving at all. Another view holds that Homo sapiens has not isolated itself from the influences of the physical and biological world but that our species is just a special, extreme case of niche constructors. This view is based on the so‐called Niche Construction Theory, a development within evolutionary biology to describe how humans—and many other organisms—modify their environment—or niche—in a way that alters environmental pressures and therefore natural selection. Thus, rather adapting to a pre‐existing environment, “organisms drive environmental change and organism‐modified environments subsequently select organisms” (https://synergy.st-andrews.ac.uk/niche/niche-construction-and-evolution/) (Box 1). ### Culture‐driven evolution “[All] organisms adapt to their environment, and in humans much of our environment is defined by our culture. Hence, cultural change can actually spur on adaptive evolution in humans”, wrote evolutionary biologist Alan Templeton at Washington University in St. Louis, MO, USA. [1]. Following this argument, culture, social learning and technology have not replaced biological adaptation. Rather, human evolution is driven by the environmental conditions we created ourselves through culture, a process that has been accelerating since the beginning of agriculture and urban civilization. In other words, cultural niche construction is a major cause of recent human evolution. However, there are other factors than natural selection, such as genetic drift and gene flow, that influence human evolution [1]. Nonetheless, even the effects of these random, non‐adaptive forces on human genetic variation are somehow altered by cultural trends, namely increased urbanization and greater mobility. As a consequence, drift is diminishing and gene flow is increasing, a process that would eventually culminate into a single “species‐wide” gene pool characterized by high levels of genetic variation. > [C]ulture, …

Slowed response to peripheral visual stimuli during strenuous exercise

Gangestad, Simpson, An Introduction to The Evolution of Mind: Why We Wanted This Book. Part I: Methodological Issues: The Means of Darwinian Behavioral Science. Issue I: How the Evolution of the Human Mind Might Be Reconstructed. Thornhill, Comprehensive Knowledge of Human Evolutionary History Requires Both Adaptationism and Phylogenetics. Hagen, Symons, Natural Psychology: The Environment of Evolutionary Adaptedness and the Structure of Cognition. Andrews, Reconstructing the Evolution of the Mind is Depressingly Difficult. Smith, Reconstructing the Evolution of the Human Mind. Mithen, How the Evolution of the Human Mind Might Be Reconstructed. Issue II: The Role of Tracking Current Evolution. Crawford, Reproductive Success: Then and Now. Mulder, On the Utility, Not the Necessity, of Tracking Current Fitness. Reeve, Sherman, Why Measuring Reproductive Success in Current Populations is Valuable: Moving Forward by Going Backward. Issue III: Our Closest Ancestors. Stanford, What Nonhuman Primates Can and Can't Teach Us about the Evolution of Mind. Silk, Who Lived in the Environment of Evolutionary Adaptedness? Lancaster, Kaplan, Chimpanzee and Human Intelligence: Life History, Diet, and the Mind. Issue IV: The Role of Examining the Costs and Benefits of Behaviors. Kaplan, Gangestad, Optimality Approaches and Evolutionary Psychology: A Call for Synthesis. DeScioli, Kurzban, The Games People Play.Kenrick, Sundie, Dynamical Evolutionary Psychology and Mathematical Modeling: Quantifying the Implications of Qualitative Biase. Part II: Fundamental MetaTheoretical Issues. Issue V: The Modularity of Mind. Ermer, Cosmides, Tooby, Functional Specialization and the Adaptationist Program. Barrett, Modules in the Flesh. Issue VI: Development as the Target of Evolution. Honeycutt, Lickliter, The Developmental Dynamics of Adaptation. Sterelny, An Alternative Evolutionary Psychology? Barrett, Development as the Target of Evolution: A Computational Approach to Developmental Systems. Lieberman, Evolutionary Psychology and Developmental Systems Theory. Thornhill, The Importance of Developmental Biology to Evolutionary Biology and Vice Versa. Issue VII: The Role of Group Selection. Wilson, The Role of Group Selection in Human Psychological Evolution. Boyd, Richerson, Group Selection: A Tale of Two Controversies. Kurzban, Aktipis, On Detecting the Footprints of Multilevel Selection in Humans. Part III: Debates Concerning Important Human Evolutionary Outcomes. Issue VIII: Key Changes in the Evolution of Human Psychology. Barrett, Cosmides, Tooby, The Hominid Entry into the Cognitive Niche. Flinn, Alexander, Runaway Social Selection in Human Evolution. Mithen, Key Changes in the Evolution of Human Psychology. Issue IX: Brain Evolution. Kaplan, Gurven, Lancaster, Brain Evolution and the Human Adaptive Complex: An Ecological and Social Theory. Dunbar, Evolution of the Social Brain. Miller, Brain Evolution. Finlay, E Pluribus Unum: Too Many Unique Human Capacities and Too Many Theories. Issue X: General Intellectual Ability. Geary, The Motivation to Control and the Evolution of General Intelligence. Kanazawa, The g-culture Coevolution. Mithen, General Intellectual Ability. Issue XI: Culture and Evolution. Boyd, Richerson, Cultural Adaptation and Maladaptation: Of Kayaks and Commissars. Boyer, The Envelope of Human Cultures and the Promise of Integrated Behavioral Sciences. Flinn, Coe, The Linked Red Queens of Human Cognition, Coalitions, and Culture. Hill, Evolutionary Biology, Cognitive Adaptations, and Human Culture. Kurzban, Representational Epidemiology: Skepticism and Gullibility. Schaller, Turning Garbage into Gold: Evolutionary Universals and Cross-Cultural Differences. Issue XII: The Evolution of Mating between the Sexes. Buss, The Evolution of Human Mating Strategies: Consequences for Conflict and Cooperation. Wood, Eagly, Social Structural Origins of Sex Differences in Human Mating. Thornhill, The Evolution of Women's Estrus, Extended Sexuality, and Concealed Ovulation, and Their Implications for Human Sexuality Research. Gangestad, Simpson, Whither Science of the Evolution of Mind?

Despite the benefits of exercise for adults, there remain concerns about safety of exercise during pregnancy. This research assessed associations between exercise prior to and during pregnancy with pregnancy outcomes and complications in a sample of 922 urban, low income, Black women. Women ages 18 years and older were enrolled in this study at 5 hospital-based or affiliated prenatal clinics located in Baltimore City. At their first prenatal visit, women completed a questionnaire about participation in strenuous (eg jogging) and non-strenuous (eg walking) exercise for fun and fitness both prior to and during pregnancy. Pregnancy outcome data (birthweight and length of gestation) and complications were obtained from clinical records. Overall, 12.2% of infants were born low birthweight (2500 grams or less). The percentages born low birthweight were not significantly different between those who did not exercise during pregnancy (11.2%), those who participated only in strenuous exercise (10.5%), those who participated only in non-strenuous exercise (12.2%) and those who participated in both strenuous and non-strenuous exercise (18.2%) (p = .53). For the full sample, 13.7% of the infants were born preterm (less than 37 weeks gestation). There were no significant differences in percent born preterm between those who did not exercise during pregnancy (14.2%), those who participated only in strenuous exercise (15.8%), those who participated only in non-strenuous exercise (13.4%), and those who participated in strenuous and non-strenuous activities (12.7%) (p = .97). There were also no statistically significant differences in spontaneous pregnancy loss according to exercise participation. Finally, the occurrence of complications of pregnancy such as bleeding, hospitalization, or abruptio placentae did not vary significantly by exercise participation prior to or during pregnancy. These results suggest that participation in physical activity did not increase risk of poor pregnancy outcomes or clinical complications in this sample.

The effect of strenuous versus moderate exercise on the metabolism of proteoglycans in articular cartilage from different weight-bearing regions of the equine third carpal bone

To test the hypothesis of whether strenuous physical exercise inhibits neutrophils that can get activated by hypobaric hypoxia, we analyzed the effects of both high altitude and strenuous exercise alone and in combination on potentially cytotoxic functions of granulocytes in healthy volunteers (n = 12 men; average age 27.6 yr; range 24-38 yr). To this end, a field study was prospectively performed with an open-labeled within-subject design comprising three protocols. Protocol I (high altitude) involved a helicopter ascent, overnight stay at 3,196 m, and descent on the following day. Protocol II (physical exercise) involved hiking below an altitude of 2,100 m with repetitive ascents amounting to a total ascent to that of protocol III. Protocol III (combination of physical exercise and high altitude) involved climbing from 1,416 to 3,196 m, stay overnight, and descent on the following day. In protocol I, number of granulocytes did not change, but potentially cytotoxic functions of cells (CD18 expression and superoxide production) were early and significantly upregulated. In protocol II, subjects developed granulocytosis, but functions of cells were inhibited. In protocol III, granulocytosis occurred at higher values than those observed under protocol II. Potentially cytotoxic functions of cells, however, were strongly inhibited again. In conclusion, high altitude alone, even moderate in extent, can activate potentially cytotoxic functions of circulating granulocytes. Strenuous physical exercise strongly inhibits this activation, which may give protection from an otherwise inflammatory injury.

Strenuous physical exercise leads to platelet activation that is normally counterbalanced by the production of endothelium-derived anti-platelet mediators, including prostacyclin (PGI2) and nitric oxide (NO). However, in the case of endothelial dysfunction, e.g. in atherosclerosis, there exists an increased risk for intravascular thrombosis during exercise that might be due to an impairment in endothelial anti-platelet mechanisms.In the present work, we evaluated platelet activation at rest and following a single bout of strenuous treadmill exercise in female ApoE/LDLR−/− mice with early (3-month-old) and advanced (7-month-old) atherosclerosis compared to female age-matched WT mice. In sedentary and post-exercise groups of animals, we analyzed TXB2 generation and the expression of platelet activation markers in the whole blood ex vivo assay. We also measured pre- and post-exercise plasma concentration of 6-keto-PGF1α, nitrite/nitrate, lipid profile, and blood cell count.Sedentary 3- and 7-month-old ApoE/LDLR−/− mice displayed significantly higher activation of platelets compared to age-matched wild-type (WT) mice, as evidenced by increased TXB2 production, expression of P-selectin, and activation of GPIIb/IIIa receptors, as well as increased fibrinogen and von Willebrand factor (vWf) binding. Interestingly, in ApoE/LDLR−/− but not in WT mice, strenuous exercise partially inhibited TXB2 production, the expression of activated GPIIb/IIIa receptors, and fibrinogen binding, with no effect on the P-selectin expression and vWf binding. Post-exercise down-regulation of the activated GPIIb/IIIa receptor expression and fibrinogen binding was not significantly different between 3- and 7-month-old ApoE/LDLR−/− mice; however, only 7-month-old ApoE/LDLR−/− mice showed lower TXB2 production after exercise. In female 4–6-month-old ApoE/LDLR−/− but not in WT mice, an elevated pre- and post-exercise plasma concentration of 6-keto-PGF1α was observed. In turn, the pre- and post-exercise plasma concentrations of nitrite (NO2−) and nitrate (NO3−) were decreased in ApoE/LDLR−/− as compared to that in age-matched WT mice.In conclusion, we demonstrated overactivation of platelets in ApoE/LDLR−/− as compared to WT mice. However, platelet activation in ApoE/LDLR−/− mice was not further increased by strenuous exercise, but was instead attenuated, a phenomenon not observed in WT mice. This phenomenon could be linked to compensatory up-regulation of PGI2-dependent anti-platelet mechanisms in ApoE/LDLR−/− mice.

Hemostasis and exercise

Music in the evolution of the mind

Strenuous exercise is associated with an inflammatory response involving the activation of several types of blood cells. In order to document the specific activation of these cell types, we studied the effect of three maximal exercise tests conducted to exhaustion on the quantitative and qualitative pattern of circulating cell-derived microparticles and inflammatory molecules in healthy subjects. This study mainly indicated that the plasma concentration of microparticles from platelets and polymorphonuclear neutrophils (PMN) was increased immediately after the strenuous exercise. In addition, the increase in plasma concentration of microparticles from PMN and platelets was still observed after 2 hours of recovery. A similar pattern was observed for the IL-6 plasma level. In contrast, no change was observed for either soluble selectins or plasma concentration of microparticles from red blood cells, monocytes and endothelial cells. In agreement, sVCAM-1 and sICAM-1 levels were not changed by the exercise. We conclude that a strenuous exercise is accompanied by platelet- and PMN-derived microparticle production that probably reflects the activation of these two cell types.

Effects on secretory IgA levels in small intestine of mice that underwent moderate exercise training followed by a bout of strenuous swimming exercise

The aim of this study was to evaluate in sedentary male subjects the effects of an acute bout of strenuous and moderate exercise on ex vivo platelet responsiveness and its possible relationship with exercise-associated modifications of oxidant-antioxidant status. An increased ADP- and collagen-evoked platelet aggregation associated with modified membrane fluidity and ion homeostasis was observed after exhaustive exercise. After moderate exercise, we found a decrease of platelet aggregation evoked by low concentrations of agonists. Strenuous exercise, but not moderate exertion, resulted in the enhanced accumulation of secondary products of lipid peroxidation, decreased total antioxidant capacity, including a diminished superoxide dismutase activity, and increased susceptibility of low-density lipoprotein (LDL) to in vitro oxidation. Acute elevation of plasma nitrite/nitrate (NOx) content was observed following each single session of physical test, whilst the platelet NOx content was decreased after strenuous exercise and increased after moderate exercise. Findings of the present study suggest that oxidative stress induced by acute strenuous exercise may interfere with platelet responsiveness most likely by promoting oxidized LDL-mediated platelet activation and by decreasing plasma and platelet-derived nitric oxide (NO) bioactivity. Moreover, our results further suggest that platelet responsiveness following an acute moderate physical stressor may depend on the efficiency of plasma and intraplatelet NO to desensitize platelets to agonist stimulation.

The purpose of this study was to examine the validity of a stages of exercise change questionnaire with self‐reported exercise, age, and body mass index (BMI) in 1,034 male and female community residents. It was found that the maintenance stage participants reported more strenuous exercise than did individuals in the other stages; and participants in the action stage reported more strenuous exercise than did individuals in the preparation and contemplation stages. There were no significant group differences among participants in the preparation, contemplation, and precontemplation stages for strenuous and moderate exercise. The maintenance stage participants engaged in more moderate exercise than did the preparation, contemplation, and precontemplation individuals; and the action stage participants reported more moderate exercise than did individuals in the preparation and precontemplation stages. The participants in the maintenance stage were older than were those in the action stage. No significant stage differences were found for mild exercise or BMI. Knowing an individual's stage of exercise change may provide researchers and practitioners with a mechanism for developing, testing, and delivering stage‐matched exercise interventions.

Technology is evolving at a rate faster than human evolution, especially human moral evolution. There are those who claim that we must morally bioenhance the human due to existential threats (such as climate change and the looming possibility of cognitive enhancement) and due to the fact that the human animal has a weak moral will. To address these existential threats, we must design human morality into human beings technologically. By moral bioenhancement, these authors mean that we must intervene technologically in the biology of the human animal in order to get it to behave morally to address these existential threats. I will bring the idea of moral bioenhancement into conversation with two philosophers of technology. Bernard Stiegler has argued that technology and culture, and thus technology and human beings, have always evolved hand in hand. Peter-Paul Verbeek notes that we have always designed morality into technology, and thus he sees technology as mediating human morality. When we offload human intentionality onto technology, Verbeek argues, technological objects and systems participate in shaping the moral subjectivity of the human actor. I will show that modern technological bioenhancement obliterates human being. Whereas in the past, human culture was handed from generation to generation through the mediation of technology, in the modern era, the human becomes the raw material upon which a technological will (imperative) rides.

Genomic surveys in humans identify a large amount of recent positive selection. Using the 3.9-million HapMap SNP dataset, we found that selection has accelerated greatly during the last 40,000 years. We tested the null hypothesis that the observed age distribution of recent positively selected linkage blocks is consistent with a constant rate of adaptive substitution during human evolution. We show that a constant rate high enough to explain the number of recently selected variants would predict (i) site heterozygosity at least 10-fold lower than is observed in humans, (ii) a strong relationship of heterozygosity and local recombination rate, which is not observed in humans, (iii) an implausibly high number of adaptive substitutions between humans and chimpanzees, and (iv) nearly 100 times the observed number of high-frequency linkage disequilibrium blocks. Larger populations generate more new selected mutations, and we show the consistency of the observed data with the historical pattern of human population growth. We consider human demographic growth to be linked with past changes in human cultures and ecologies. Both processes have contributed to the extraordinarily rapid recent genetic evolution of our species.