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Willi Y, Kristensen TN, Sgrò CM, Weeks AR, Ørsted M, Hoffmann AA. Conservation genetics as a management tool: The five best-supported paradigms to assist the management of threatened species. Proc Natl Acad Sci U S A 2022; 119:e2105076119. [PMID: 34930821 PMCID: PMC8740573 DOI: 10.1073/pnas.2105076119] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
About 50 y ago, Crow and Kimura [An Introduction to Population Genetics Theory (1970)] and Ohta and Kimura [Genet. Res. 22, 201-204 (1973)] laid the foundations of conservation genetics by predicting the relationship between population size and genetic marker diversity. This work sparked an enormous research effort investigating the importance of population dynamics, in particular small population size, for population mean performance, population viability, and evolutionary potential. In light of a recent perspective [J. C. Teixeira, C. D. Huber, Proc. Natl. Acad. Sci. U.S.A. 118, 10 (2021)] that challenges some fundamental assumptions in conservation genetics, it is timely to summarize what the field has achieved, what robust patterns have emerged, and worthwhile future research directions. We consider theory and methodological breakthroughs that have helped management, and we outline some fundamental and applied challenges for conservation genetics.
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Affiliation(s)
- Yvonne Willi
- Department of Environmental Sciences, University of Basel, 4056 Basel, Switzerland
| | - Torsten N Kristensen
- Department of Chemistry and Bioscience, Aalborg University, Aalborg 9220, Denmark
| | - Carla M Sgrò
- School of Biological Sciences, Monash University, Melbourne, VIC 3800, Australia
| | - Andrew R Weeks
- School of BioSciences, Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia
- Cesar Australia, Brunswick, VIC 3056, Australia
| | - Michael Ørsted
- Department of Chemistry and Bioscience, Aalborg University, Aalborg 9220, Denmark
- Department of Biology, Aarhus University, Aarhus 8000, Denmark
| | - Ary A Hoffmann
- School of BioSciences, Bio21 Institute, University of Melbourne, Melbourne, VIC 3010, Australia;
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Moorad J, Ravindran S. Natural selection and the evolution of asynchronous aging. Am Nat 2021; 199:551-563. [DOI: 10.1086/718589] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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3
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Long-term mating positively predicts both reproductive fitness and parental investment. J Biosoc Sci 2021; 54:912-923. [PMID: 34365983 DOI: 10.1017/s0021932021000407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Empirical data on the relations between mating and reproductive success are rare for humans, especially for industrial and post-industrial populations. Existing data show that mating (and especially long-term mating) can be beneficial for fitness, especially that of males. This finding is in line with the hypothesis of sexual selection operating in human populations. The present research expands on previous studies by: 1) analysing additional fitness indicators, including having children with different partners; 2) including parental investment in the analysis as another important marker of sexual selection; 3) analysing several mediators between mating, reproductive fitness and parental investment, i.e. age of first and last reproduction and desired number of children. The data were obtained in 2019 from a sample of parents living in Serbia (N=497). The findings showed that long-term mating (duration of longest partner relationship) was positively related to parental investment and number of offspring and grand-offspring. Furthermore, the link between long-term mating and reproductive success was completely mediated by the age of first reproduction and desired number of children. Short-term mating (number of sexual partners) was marginally positively related to the number of children participants had with different partners and negatively related to parental investment. No sex differences in the link between mating, fitness and parental investment were detected. In general, the signatures of sexual selection were weak in the present data, but those that were detected were in line with sexual selection theory. The present findings provide a deeper insight into the adaptive function of mating and also the mechanism of how mating is beneficial for fitness.
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Moorad J, Promislow D, Silvertown J. Evolutionary Ecology of Senescence and a Reassessment of Williams' 'Extrinsic Mortality' Hypothesis. Trends Ecol Evol 2019; 34:519-530. [PMID: 30857756 DOI: 10.1016/j.tree.2019.02.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 02/08/2019] [Accepted: 02/12/2019] [Indexed: 10/27/2022]
Abstract
The evolutionary theory of senescence underpins research in life history evolution and the biology of aging. In 1957 G.C. Williams predicted that higher adult death rates select for earlier senescence and shorter length of life, but preadult mortality does not matter to the evolution of senescence. This was subsequently interpreted as predicting that senescence should be caused by 'extrinsic' sources of mortality. This idea still motivates empirical studies, although formal, mathematical theory shows it is wrong. It has nonetheless prospered because it offers an intuitive explanation for patterns observed in nature. We review the flaws in Williams' model, explore alternative explanations for comparative patterns that are consistent with the evolutionary theory of senescence, and discuss how hypotheses based on it can be tested. We argue that focusing on how sources of mortality affect ages differently offers greater insight into evolutionary processes.
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Affiliation(s)
- Jacob Moorad
- Institute of Evolutionary Biology, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Daniel Promislow
- Department of Pathology and Department of Biology, University of Washington, Seattle, WA, USA. https://twitter.com@DPromislow
| | - Jonathan Silvertown
- Institute of Evolutionary Biology, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK. https://twitter.com@JWSilvertown
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McGovern ME. How much does birth weight matter for child health in developing countries? Estimates from siblings and twins. HEALTH ECONOMICS 2019; 28:3-22. [PMID: 30239053 DOI: 10.1002/hec.3823] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 07/18/2018] [Accepted: 08/04/2018] [Indexed: 06/08/2023]
Abstract
About 200 million children globally are not meeting their growth potential, and as a result will suffer the consequences in terms of future outcomes. I examine the effects of birth weight on child health and growth using information from 66 countries. I account for missing data and measurement error using instrumental variables and adopt an identification strategy based on siblings and twins. I find a consistent effect of birth weight on mortality risk, stunting, wasting, and coughing, with some evidence for fever, diarrhoea, and anaemia. Bounds analysis indicates that coefficients may be substantially underestimated due to mortality selection. Improving the pre-natal environment is likely to be important for helping children reach their full potential.
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Affiliation(s)
- Mark E McGovern
- Centre of Excellence for Public Health (Northern Ireland), and Queen's Management School, Queen's University Belfast, Belfast, UK
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Corbett S, Courtiol A, Lummaa V, Moorad J, Stearns S. The transition to modernity and chronic disease: mismatch and natural selection. Nat Rev Genet 2018; 19:419-430. [DOI: 10.1038/s41576-018-0012-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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8
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Pujol B, Blanchet S, Charmantier A, Danchin E, Facon B, Marrot P, Roux F, Scotti I, Teplitsky C, Thomson CE, Winney I. The Missing Response to Selection in the Wild. Trends Ecol Evol 2018; 33:337-346. [PMID: 29628266 PMCID: PMC5937857 DOI: 10.1016/j.tree.2018.02.007] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 02/26/2018] [Accepted: 02/28/2018] [Indexed: 01/28/2023]
Abstract
Although there are many examples of contemporary directional selection, evidence for responses to selection that match predictions are often missing in quantitative genetic studies of wild populations. This is despite the presence of genetic variation and selection pressures – theoretical prerequisites for the response to selection. This conundrum can be explained by statistical issues with accurate parameter estimation, and by biological mechanisms that interfere with the response to selection. These biological mechanisms can accelerate or constrain this response. These mechanisms are generally studied independently but might act simultaneously. We therefore integrated these mechanisms to explore their potential combined effect. This has implications for explaining the apparent evolutionary stasis of wild populations and the conservation of wildlife. Recent discoveries at the intersection of quantitative genetics and evolutionary ecology are challenging our views on the potential of wild populations to respond to selection. Multiple biological mechanisms can disconnect genetic variation from the response to selection in the wild. We highlight areas for future research. We provide an integrative framework that can be used to qualitatively assess the combined influence of these mechanisms on the response to selection.
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Affiliation(s)
- Benoit Pujol
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 31062 Toulouse, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France.
| | - Simon Blanchet
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 31062 Toulouse, France; Station d'Ecologie Théorique Expérimentale (SETE), CNRS UMR 5321, Université Paul Sabatier, 09200 Moulis, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Anne Charmantier
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), CNRS UMR 5175, 34293 Montpellier, France; Département des Sciences Biologiques, Université du Québec à Montréal, CP 888 Succursale Centre-Ville, H3P 3P8 QC, Canada; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Etienne Danchin
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 31062 Toulouse, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Benoit Facon
- UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), Institut National de la Recherche Agronomique (INRA), Saint Pierre, Réunion, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Pascal Marrot
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 31062 Toulouse, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Fabrice Roux
- Laboratoire des Interactions Plantes-Microorganismes (LIPM), INRA, CNRS, Université de Toulouse, 31326 Castanet-Tolosan, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Ivan Scotti
- INRA Unité de Recherche 0629 Ecologie des Forêts Méditerranéennes, 84914 Avignon, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Céline Teplitsky
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), CNRS UMR 5175, 34293 Montpellier, France; Muséum National d'Histoire Naturelle, CNRS UMR 7204 Centre d'Écologie et des Sciences de la Conservation (CESCO), 75005 Paris, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Caroline E Thomson
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 31062 Toulouse, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
| | - Isabel Winney
- Laboratoire Évolution & Diversité Biologique (EDB UMR 5174), Université Fédérale de Toulouse Midi-Pyrénées, CNRS, IRD, UPS, 31062 Toulouse, France; Groupement de Recherche de l'Institut Ecologie et Environnement 6448, Génétique Quantitative dans les Populations Naturelles (GQPN), c/o EDB, 31062 Toulouse, France
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10
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Measuring selection for genes that promote long life in a historical human population. Nat Ecol Evol 2017; 1:1773-1781. [DOI: 10.1038/s41559-017-0329-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 08/30/2017] [Indexed: 11/08/2022]
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Mother's curse neutralizes natural selection against a human genetic disease over three centuries. Nat Ecol Evol 2017; 1:1400-1406. [PMID: 29046555 DOI: 10.1038/s41559-017-0276-6] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 06/06/2017] [Indexed: 12/30/2022]
Abstract
According to evolutionary theory, mitochondria could be poisoned gifts that mothers transmit to their sons. This is because mutations harmful to males are expected to accumulate in the mitochondrial genome, the so-called 'mother's curse'. However, the contribution of the mother's curse to the mutation load in nature remains largely unknown and hard to predict, because compensatory mechanisms could impede the spread of deleterious mitochondria. Here we provide evidence for the mother's curse in action over 290 years in a human population. We studied a mutation causing Leber's hereditary optical neuropathy, a disease with male-biased prevalence and which has long been suspected to be maintained in populations by the mother's curse. Male carriers showed a low fitness relative to non-carriers and to females, mostly explained by their high rate of infant mortality. Despite poor male fitness, selection analysis predicted a slight (albeit non-significant) increase in frequency, which sharply contrasts with the 35.5% per-generation decrease predicted if mitochondrial DNA transmission had been through males instead of females. Our results are therefore even suggestive of positive selection through the female line that may exacerbate effects of the mother's curse. This study supports a contribution of the mother's curse to the reduction of male lifespan, uncovering a large fitness effect associated with a single mitochondrial variant.
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12
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The Reproductive Ecology of Industrial Societies, Part I : Why Measuring Fertility Matters. HUMAN NATURE-AN INTERDISCIPLINARY BIOSOCIAL PERSPECTIVE 2017; 27:422-444. [PMID: 27670436 PMCID: PMC5107203 DOI: 10.1007/s12110-016-9269-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Is fertility relevant to evolutionary analyses conducted in modern industrial societies? This question has been the subject of a highly contentious debate, beginning in the late 1980s and continuing to this day. Researchers in both evolutionary and social sciences have argued that the measurement of fitness-related traits (e.g., fertility) offers little insight into evolutionary processes, on the grounds that modern industrial environments differ so greatly from those of our ancestral past that our behavior can no longer be expected to be adaptive. In contrast, we argue that fertility measurements in industrial society are essential for a complete evolutionary analysis: in particular, such data can provide evidence for any putative adaptive mismatch between ancestral environments and those of the present day, and they can provide insight into the selection pressures currently operating on contemporary populations. Having made this positive case, we then go on to discuss some challenges of fertility-related analyses among industrialized populations, particularly those that involve large-scale databases. These include “researcher degrees of freedom” (i.e., the choices made about which variables to analyze and how) and the different biases that may exist in such data. Despite these concerns, large datasets from multiple populations represent an excellent opportunity to test evolutionary hypotheses in great detail, enriching the evolutionary understanding of human behavior.
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GEOSPATIAL ASSESSMENT BASED ON FERTILITY AND MORTALITY DIFFERENTIAL INDICES OF NATURAL SELECTION IN NORTH-WEST AND EASTERN HIMALAYAN POPULATIONS. J Biosoc Sci 2016; 49:811-825. [PMID: 27995836 DOI: 10.1017/s0021932016000705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
There is contradictory evidence of having fewer live births and higher embryonic mortality among high-altitude populations than their counterparts at lower altitude. This study explores the geospatial differences in selection intensities among human populations living in different ecological settings. Reproductive data from post-menopausal women were collected from 75 women from near Shimla, Himachal Pradesh, at an altitude of 2150 m above sea level and 100 women from Jind, Haryana, at an altitude of 227 m. Secondary data were taken from 85 women from the Kinnaur district of Himachal Pradesh at an average altitude of 3420 m. A comparison of the study data was made with similar data from different populations living in the western and eastern Himalayas. The total selection intensity index based on Johnston and Kensinger's index was highest in Shimla and lowest in Kinnaur. The fertility selection component was highest in Shimla and lowest in Kinnaur. The prenatal mortality contribution to the total selection was highest in Shimla (30.76%) and lowest in Kinnaur (2.14%), while the contributions of normalized postnatal mortality were 16.39% and 57.80% in Shimla and Kinnaur, respectively. The fertility component of selection was higher than the mortality component in Shimla, while in the other two places the reverse was observed. Hypoxic conditions at high altitude seem to have little effect on the fertility and embryonic mortality rates of indigenous people. The geospatial differences in the selection intensities may be due to differences in ethnic, behavioural ecology, environmental, cultural and socioeconomic factors.
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Beauchamp JP. Genetic evidence for natural selection in humans in the contemporary United States. Proc Natl Acad Sci U S A 2016; 113:7774-9. [PMID: 27402742 PMCID: PMC4948342 DOI: 10.1073/pnas.1600398113] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Recent findings from molecular genetics now make it possible to test directly for natural selection by analyzing whether genetic variants associated with various phenotypes have been under selection. I leverage these findings to construct polygenic scores that use individuals' genotypes to predict their body mass index, educational attainment (EA), glucose concentration, height, schizophrenia, total cholesterol, and (in females) age at menarche. I then examine associations between these scores and fitness to test whether natural selection has been occurring. My study sample includes individuals of European ancestry born between 1931 and 1953 who participated in the Health and Retirement Study, a representative study of the US population. My results imply that natural selection has been slowly favoring lower EA in both females and males, and are suggestive that natural selection may have favored a higher age at menarche in females. For EA, my estimates imply a rate of selection of about -1.5 mo of education per generation (which pales in comparison with the increases in EA observed in contemporary times). Although they cannot be projected over more than one generation, my results provide additional evidence that humans are still evolving-albeit slowly, especially compared with the rapid changes that have occurred over the past few generations due to cultural and environmental factors.
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15
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Scranton K, Lummaa V, Stearns SC. The importance of the timescale of the fitness metric for estimates of selection on phenotypic traits during a period of demographic change. Ecol Lett 2016; 19:854-61. [DOI: 10.1111/ele.12619] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 04/12/2016] [Accepted: 04/21/2016] [Indexed: 11/26/2022]
Affiliation(s)
- Katherine Scranton
- Department of Ecology and Evolutionary Biology; Yale University; 165 Prospect Street CT 06520-8102 New Haven CT USA
| | - Virpi Lummaa
- Department of Biology; University of Turku; FI-20014 Turku Finland
| | - Stephen C. Stearns
- Department of Ecology and Evolutionary Biology; Yale University; 165 Prospect Street CT 06520-8102 New Haven CT USA
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Burger O, DeLong JP. What if fertility decline is not permanent? The need for an evolutionarily informed approach to understanding low fertility. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150157. [PMID: 27022084 PMCID: PMC4822437 DOI: 10.1098/rstb.2015.0157] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/21/2016] [Indexed: 01/13/2023] Open
Abstract
'Demographic transition theory' assumes that fertility decline is irreversible. This commonly held assumption is based on observations of recent and historical reductions in fertility that accompany modernization and declining mortality. The irreversibility assumption, however, is highly suspect from an evolutionary point of view, because demographic traits are at least partially influenced by genetics and are responsive to social and ecological conditions. Nonetheless, an inevitable shift from high mortality and fertility to low mortality and fertility is used as a guiding framework for projecting human population sizes into the future. This paper reviews some theoretical and empirical evidence suggesting that the assumption of irreversibility is ill-founded, at least without considerable development in theory that incorporates evolutionary and ecological processes. We offer general propositions for how fertility could increase in the future, including natural selection on high fertility variants, the difficulty of maintaining universal norms and preferences in a large, diverse and economically differentiated population, and the escalating resource demands of modernization.
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Affiliation(s)
- Oskar Burger
- School of Anthropology and Conservation, University of Kent, Canterbury CT27NR, UK Max Planck Institute for Demographic Research, Konrad-Zuse-Strasse 1, Rostock 18057, Germany
| | - John P DeLong
- School of Biological Sciences, University of Nebraska, Lincoln, Lincoln, NE, USA
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Bolund E, Lummaa V, Smith KR, Hanson HA, Maklakov AA. Reduced costs of reproduction in females mediate a shift from a male-biased to a female-biased lifespan in humans. Sci Rep 2016; 6:24672. [PMID: 27087670 PMCID: PMC4834564 DOI: 10.1038/srep24672] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 04/04/2016] [Indexed: 11/21/2022] Open
Abstract
The causes underlying sex differences in lifespan are strongly debated. While females commonly outlive males in humans, this is generally less pronounced in societies before the demographic transition to low mortality and fertility rates. Life-history theory suggests that reduced reproduction should benefit female lifespan when females pay higher costs of reproduction than males. Using unique longitudinal demographic records on 140,600 reproducing individuals from the Utah Population Database, we demonstrate a shift from male-biased to female-biased adult lifespans in individuals born before versus during the demographic transition. Only women paid a cost of reproduction in terms of shortened post-reproductive lifespan at high parities. Therefore, as fertility decreased over time, female lifespan increased, while male lifespan remained largely stable, supporting the theory that differential costs of reproduction in the two sexes result in the shifting patterns of sex differences in lifespan across human populations. Further, our results have important implications for demographic forecasts in human populations and advance our understanding of lifespan evolution.
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Affiliation(s)
- Elisabeth Bolund
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala SE-752 36, Sweden
| | - Virpi Lummaa
- Department of Biology, University of Turku, FIN-20014 Turku, Finland.,Department of Animal &Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Ken R Smith
- Department of Family and Consumer Studies and Population Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Heidi A Hanson
- Department of Family and Preventive Medicine and Population Sciences, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Alexei A Maklakov
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala SE-752 36, Sweden
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Camara AD, Roman JG. Anthropometric geography applied to the analysis of socioeconomic disparities: cohort trends and spatial patterns of height and robustness in 20 th-century Spain. POPULATION, SPACE AND PLACE 2015; 21:704-719. [PMID: 26640422 PMCID: PMC4666548 DOI: 10.1002/psp.1850] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Anthropometrics have been widely used to study the influence of environmental factors on health and nutritional status. In contrast, anthropometric geography has not often been employed to approximate the dynamics of spatial disparities associated with socioeconomic and demographic changes. Spain exhibited intense disparity and change during the middle decades of the 20th century, with the result that the life courses of the corresponding cohorts were associated with diverse environmental conditions. This was also true of the Spanish territories. This paper presents insights concerning the relationship between socioeconomic changes and living conditions by combining the analysis of cohort trends and the anthropometric cartography of height and physical build. This analysis is conducted for Spanish male cohorts born 1934-1973 that were recorded in the Spanish military statistics. This information is interpreted in light of region-level data on GDP and infant mortality. Our results show an anthropometric convergence across regions that, nevertheless, did not substantially modify the spatial patterns of robustness, featuring primarily robust northeastern regions and weak Central-Southern regions. These patterns persisted until the 1990s (cohorts born during the 1970s). For the most part, anthropometric disparities were associated with socioeconomic disparities, although the former lessened over time to a greater extent than the latter. Interestingly, the various anthropometric indicators utilized here do not point to the same conclusions. Some discrepancies between height and robustness patterns have been found that moderate the statements from the analysis of cohort height alone regarding the level and evolution of living conditions across Spanish regions.
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Affiliation(s)
| | - Joan Garcia Roman
- Minnesota Population Center, University of Minnesota, Minneapolis, MN, USA
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Bolund E, Hayward A, Pettay JE, Lummaa V. Effects of the demographic transition on the genetic variances and covariances of human life-history traits. Evolution 2015; 69:747-55. [DOI: 10.1111/evo.12598] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 12/05/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Elisabeth Bolund
- Department of Animal & Plant Sciences; University of Sheffield; Sheffield S10 2TN United Kingdom
- Evolutionary Biology Centre; Uppsala University; Uppsala SE-752 36 Sweden
| | - Adam Hayward
- Department of Animal & Plant Sciences; University of Sheffield; Sheffield S10 2TN United Kingdom
| | - Jenni E. Pettay
- Department of Biology; University of Turku; Turku FIN-20014 Finland
| | - Virpi Lummaa
- Department of Animal & Plant Sciences; University of Sheffield; Sheffield S10 2TN United Kingdom
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Engen S, Kvalnes T, Sæther BE. Estimating phenotypic selection in age-structured populations by removing transient fluctuations. Evolution 2014; 68:2509-23. [PMID: 24889690 DOI: 10.1111/evo.12456] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 05/08/2014] [Indexed: 11/26/2022]
Abstract
An extension of the selection differential in the Robertson-Price equation for the mean phenotype in an age-structured population is provided. Temporal changes in the mean phenotype caused by transient fluctuations in the age-distribution and variation in mean phenotype among age classes, which can mistakenly be interpreted as selection, will disappear if reproductive value weighting is applied. Changes in any weighted mean phenotype in an age-structured population may be decomposed into between- and within-age class components. Using reproductive value weighting the between-age class component becomes pure noise, generated by previous genetic drift or fluctuating selection. This component, which we call transient quasi-selection, can therefore be omitted when estimating age-specific selection on fecundity or viability within age classes. The final response can be computed at the time of selection, but can not be observed until lifetime reproduction is realized unless the heritability is one. The generality of these results is illustrated further by our derivation of the selection differential for the continuous time age-structured model with general age-dependent weights. A simple simulation example as well as estimation of selection components in a house sparrow population illustrates the applicability of the theory to analyze selection on the mean phenotype in fluctuating age-structured populations.
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Affiliation(s)
- Steinar Engen
- Centre for Biodiversity Dynamics, Department of Mathematical Sciences, , Norwegian University of Science and Technology, N-7491, Trondheim, Norway
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21
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Abstract
Powerful multiple regression-based approaches are commonly used to measure the strength of phenotypic selection, which is the statistical association between individual fitness and trait values. Age structure and overlapping generations complicate determinations of individual fitness, contributing to the popularity of alternative methods for measuring natural selection that do not depend upon such measures. The application of regression-based techniques for measuring selection in these situations requires a demographically appropriate, conceptually sound, and observable measure of individual fitness. It has been suggested that Fisher's reproductive value applied to an individual at its birth is such a definition. Here I offer support for this assertion by showing that multiple regression applied to this measure and vital rates (age-specific survival and fertility rates) yields the same selection gradients for vital rates as those inferred from Hamilton's classical results. I discuss how multiple regressions, applied to individual reproductive value at birth, can be used efficiently to estimate measures of phenotypic selection that are problematic for sensitivity analyses. These include nonlinear selection, components of the opportunity for selection, and multilevel selection.
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Affiliation(s)
- Jacob A. Moorad
- Duke Population Research Institute & Biology Department Box 90338 Duke University Durham, NC
- Institute of Evolutionary Biology The University of Edinburgh The Kings Buildings, Ashworth Laboratories, West Mains Road Edinburgh, UK
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22
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Abstract
Despite popular misconceptions, natural selection does operate in modern human populations. New studies even show that changes associated with modernization are deeply reshaping selection pressures and, perhaps, bits of our biological nature.
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Affiliation(s)
- Emmanuel Milot
- Groupe de recherche PRIMUS, Département de médecine de famille, Université de Sherbrooke, CHUS-Fleurimont, Sherbrooke, Québec, Canada.
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23
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Moorad JA. Multi-level sexual selection: individual and family-level selection for mating success in a historical human population. Evolution 2013; 67:1635-48. [PMID: 23730758 PMCID: PMC3675801 DOI: 10.1111/evo.12050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 01/03/2013] [Indexed: 12/01/2022]
Abstract
Precopulatory sexual selection is the association between fitness and traits associated with mate acquisition. Although sexual selection is generally recognized to be a powerful evolutionary force, most investigations are limited to characters belonging to individuals. A broader multilevel perspective acknowledges that individual fitness can be affected by aspects of mating success that are characters of groups, such as families. Parental mating success in polygynous or polyandrous human societies may exemplify traits under group-level sexual selection. Using fitness measures that account for age-structure, I measure multilevel selection for mate number over 55 years in a human population with declining rates of polygyny. Sexual selection had three components: individual-level selection for ever-mating (whether an individual mated) and individual- and family-level selection for polyandry and polygyny. Family- and individual-level selection for polygyny was equally strong, three times stronger than family-level selection for polyandry and more than an order of magnitude stronger than individual-level selection for polyandry. However, individual-level selection for polyandry and polygyny was more effective at explaining relative fitness variance than family-level selection. Selection for ever-mating was the most important source of sexual selection for fitness; variation for ever-mating explained 23% of relative fitness variance.
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Affiliation(s)
- Jacob A Moorad
- Duke Population Research Institute & Biology Department, 8, Duke University, Durham, North Carolina, USA.
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Courtiol A, Rickard I, Lummaa V, Prentice A, Fulford A, Stearns S. The demographic transition influences variance in fitness and selection on height and BMI in rural Gambia. Curr Biol 2013; 23:884-9. [PMID: 23623548 PMCID: PMC3668323 DOI: 10.1016/j.cub.2013.04.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 02/04/2013] [Accepted: 04/02/2013] [Indexed: 11/29/2022]
Abstract
Recent human history is marked by demographic transitions characterized by declines in mortality and fertility. By influencing the variance in those fitness components, demographic transitions can affect selection on other traits. Parallel to changes in selection triggered by demography per se, relationships between fitness and anthropometric traits are also expected to change due to modification of the environment. Here we explore for the first time these two main evolutionary consequences of demographic transitions using a unique data set containing survival, fertility, and anthropometric data for thousands of women in rural Gambia from 1956-2010. We show how the demographic transition influenced directional selection on height and body mass index (BMI). We observed a change in selection for both traits mediated by variation in fertility: selection initially favored short females with high BMI values but shifted across the demographic transition to favor tall females with low BMI values. We demonstrate that these differences resulted both from changes in fitness variance that shape the strength of selection and from shifts in selective pressures triggered by environmental changes. These results suggest that demographic and environmental trends encountered by current human populations worldwide are likely to modify, but not stop, natural selection in humans.
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Affiliation(s)
- Alexandre Courtiol
- Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, 10315 Berlin, Germany
- Wissenschaftskolleg zu Berlin, 14193 Berlin, Germany
| | - Ian J. Rickard
- Wissenschaftskolleg zu Berlin, 14193 Berlin, Germany
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
- Department of Anthropology, Durham University, Durham DH1 3LE, UK
| | - Virpi Lummaa
- Wissenschaftskolleg zu Berlin, 14193 Berlin, Germany
- Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK
| | - Andrew M. Prentice
- MRC Keneba, The Gambia
- MRC International Nutrition Group, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Anthony J.C. Fulford
- MRC Keneba, The Gambia
- MRC International Nutrition Group, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Stephen C. Stearns
- Wissenschaftskolleg zu Berlin, 14193 Berlin, Germany
- Department of Ecology and Evolutionary Biology, Yale University, CT 06520-8102, USA
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25
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Moorad JA, Wade MJ. Selection gradients, the opportunity for selection, and the coefficient of determination. Am Nat 2013; 181:291-300. [PMID: 23448880 PMCID: PMC3620722 DOI: 10.1086/669158] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Abstract We derive the relationship between R(2) (the coefficient of determination), selection gradients, and the opportunity for selection for univariate and multivariate cases. Our main result is to show that the portion of the opportunity for selection that is caused by variation for any trait is equal to the product of its selection gradient and its selection differential. This relationship is a corollary of the first and second fundamental theorems of natural selection, and it permits one to investigate the portions of the total opportunity for selection that are involved in directional selection, stabilizing (and diversifying) selection, and correlational selection, which is important to morphological integration. It also allows one to determine the fraction of fitness variation not explained by variation in measured phenotypes and therefore attributable to random (or, at least, unknown) influences. We apply our methods to a human data set to show how sex-specific mating success as a component of fitness variance can be decoupled from that owing to prereproductive mortality. By quantifying linear sources of sexual selection and quadratic sources of sexual selection, we illustrate that the former is stronger in males, while the latter is stronger in females.
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Affiliation(s)
- Jacob A Moorad
- Duke Population Research Institute and Department of Biology, Duke University, Durham, NC 27708, USA.
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