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Rosenbaum S, Malani A, Lea AJ, Tung J, Alberts SC, Archie EA. Testing frameworks for early life effects: the developmental constraints and adaptive response hypotheses do not explain key fertility outcomes in wild female baboons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.23.590627. [PMID: 38712305 PMCID: PMC11071398 DOI: 10.1101/2024.04.23.590627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
In evolutionary ecology, two classes of explanations are frequently invoked to explain "early life effects" on adult outcomes. Developmental constraints (DC) explanations contend that costs of early adversity arise from limitations adversity places on optimal development. Adaptive response (AR) hypotheses propose that later life outcomes will be worse when early and adult environments are poorly "matched." Here, we use recently proposed mathematical definitions for these hypotheses and a quadratic-regression based approach to test the long-term consequences of variation in developmental environments on fertility in wild baboons. We evaluate whether low rainfall and/or dominance rank during development predict three female fertility measures in adulthood, and whether any observed relationships are consistent with DC and/or AR. Neither rainfall during development nor the difference between rainfall in development and adulthood predicted any fertility measures. Females who were low-ranking during development had an elevated risk of losing infants later in life, and greater change in rank between development and adulthood predicted greater risk of infant loss. However, both effects were statistically marginal and consistent with alternative explanations, including adult environmental quality effects. Consequently, our data do not provide compelling support for either of these common explanations for the evolution of early life effects.
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Affiliation(s)
| | - Anup Malani
- University of Chicago Law School & National Bureau of Economic Research
| | - Amanda J Lea
- Department of Biological Sciences, Vanderbilt University
| | - Jenny Tung
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary, Anthropology; Departments of Evolutionary Anthropology & Biology, Duke University
| | - Susan C Alberts
- Departments of Evolutionary Anthropology & Biology, Duke University
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2
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Anderson JA, Lin D, Lea AJ, Johnston RA, Voyles T, Akinyi MY, Archie EA, Alberts SC, Tung J. DNA methylation signatures of early-life adversity are exposure-dependent in wild baboons. Proc Natl Acad Sci U S A 2024; 121:e2309469121. [PMID: 38442181 PMCID: PMC10945818 DOI: 10.1073/pnas.2309469121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 12/13/2023] [Indexed: 03/07/2024] Open
Abstract
The early-life environment can profoundly shape the trajectory of an animal's life, even years or decades later. One mechanism proposed to contribute to these early-life effects is DNA methylation. However, the frequency and functional importance of DNA methylation in shaping early-life effects on adult outcomes is poorly understood, especially in natural populations. Here, we integrate prospectively collected data on fitness-associated variation in the early environment with DNA methylation estimates at 477,270 CpG sites in 256 wild baboons. We find highly heterogeneous relationships between the early-life environment and DNA methylation in adulthood: aspects of the environment linked to resource limitation (e.g., low-quality habitat, early-life drought) are associated with many more CpG sites than other types of environmental stressors (e.g., low maternal social status). Sites associated with early resource limitation are enriched in gene bodies and putative enhancers, suggesting they are functionally relevant. Indeed, by deploying a baboon-specific, massively parallel reporter assay, we show that a subset of windows containing these sites are capable of regulatory activity, and that, for 88% of early drought-associated sites in these regulatory windows, enhancer activity is DNA methylation-dependent. Together, our results support the idea that DNA methylation patterns contain a persistent signature of the early-life environment. However, they also indicate that not all environmental exposures leave an equivalent mark and suggest that socioenvironmental variation at the time of sampling is more likely to be functionally important. Thus, multiple mechanisms must converge to explain early-life effects on fitness-related traits.
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Affiliation(s)
- Jordan A. Anderson
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
| | - Dana Lin
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
| | - Amanda J. Lea
- Canadian Institute for Advanced Research, Child & Brain Development Program, Toronto, ONM5G 1M1, Canada
- Department of Biological Sciences, Vanderbilt University, Nashville, TN37235
| | | | - Tawni Voyles
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
| | - Mercy Y. Akinyi
- Institute of Primate Research, National Museums of Kenya, Nairobi00502, Kenya
| | - Elizabeth A. Archie
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN46556
| | - Susan C. Alberts
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
- Department of Biology, Duke University, Durham, NC27708
- Duke Population Research Institute, Duke University, Durham, NC27708
| | - Jenny Tung
- Department of Evolutionary Anthropology, Duke University, Durham, NC27708
- Canadian Institute for Advanced Research, Child & Brain Development Program, Toronto, ONM5G 1M1, Canada
- Department of Biology, Duke University, Durham, NC27708
- Duke Population Research Institute, Duke University, Durham, NC27708
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig04103, Germany
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3
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Levy EJ, Lee A, Siodi IL, Helmich EC, McLean EM, Malone EJ, Pickard MJ, Ranjithkumar R, Tung J, Archie EA, Alberts SC. Early life drought predicts components of adult body size in wild female baboons. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2023; 182:357-371. [PMID: 37737520 PMCID: PMC10591920 DOI: 10.1002/ajpa.24849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 08/14/2023] [Accepted: 08/28/2023] [Indexed: 09/23/2023]
Abstract
OBJECTIVES In many taxa, adverse early-life environments are associated with reduced growth and smaller body size in adulthood. However, in wild primates, we know very little about whether, where, and to what degree trajectories are influenced by early adversity, or which types of early adversity matter most. Here, we use parallel-laser photogrammetry to assess inter-individual predictors of three measures of body size (leg length, forearm length, and shoulder-rump length) in a population of wild female baboons studied since birth. MATERIALS AND METHODS Using >2000 photogrammetric measurements of 127 females, we present a cross-sectional growth curve of wild female baboons (Papio cynocephalus) from juvenescence through adulthood. We then test whether females exposed to several important sources of early-life adversity-drought, maternal loss, low maternal rank, or a cumulative measure of adversity-were smaller for their age than females who experienced less adversity. Using the "animal model," we also test whether body size is heritable in this study population. RESULTS Prolonged early-life drought predicted shorter limbs but not shorter torsos (i.e., shoulder-rump lengths). Our other measures of early-life adversity did not predict variation in body size. Heritability estimates for body size measures were 36%-67%. Maternal effects accounted for 13%-17% of the variance in leg and forearm length, but no variance in torso length. DISCUSSION Our results suggest that baboon limbs, but not torsos, grow plastically in response to maternal effects and energetic early-life stress. Our results also reveal considerable heritability for all three body size measures in this study population.
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Affiliation(s)
- Emily J. Levy
- Department of Biology, Indiana University, Bloomington IN 47405, USA
- Department of Biology, Duke University, Durham NC 27708, USA
| | - Anna Lee
- Department of Biology, Duke University, Durham NC 27708, USA
| | | | - Emma C. Helmich
- Department of Biology, Duke University, Durham NC 27708, USA
| | - Emily M. McLean
- Division of Natural Sciences, Oxford College of Emory University, Oxford, GA, 30054, USA
| | - Elise J. Malone
- Department of Biology, Duke University, Durham NC 27708, USA
| | | | - Riddhi Ranjithkumar
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA
| | - Jenny Tung
- Department of Biology, Duke University, Durham NC 27708, USA
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Evolutionary Anthropology, Duke University, Durham NC 27708, USA
- Canadian Institute for Advanced Research, Toronto, Canada M5G 1M1, Canada
| | - Elizabeth A. Archie
- Department of Biological Sciences, University of Notre Dame, Notre Dame IN, 46556, USA
| | - Susan C. Alberts
- Department of Biology, Duke University, Durham NC 27708, USA
- Department of Evolutionary Anthropology, Duke University, Durham NC 27708, USA
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4
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Dib S, Fewtrell M, Wells JCK. Maternal capital predicts investment in infant growth and development through lactation. Front Nutr 2023; 10:1272938. [PMID: 37885440 PMCID: PMC10598761 DOI: 10.3389/fnut.2023.1272938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 09/15/2023] [Indexed: 10/28/2023] Open
Abstract
Introduction Maternal capital (MC) is a broad term from evolutionary biology, referring to any aspects of maternal phenotype that represent resources available for investment in offspring. We investigated MC in breastfeeding mothers of late preterm and early term infants, examining its relationship with infant and breastfeeding outcomes. We also determined whether MC modified the effect of the relaxation intervention on these outcomes. Methods The data was collected as part of a randomized controlled trial investigating breastfeeding relaxation in 72 mothers of late preterm and early term infants. Indicators of MC (socioeconomic, social, somatic, reproductive, psychological, and cognitive) were collected at baseline at 2-3 weeks post-delivery. Principal Component Analysis was conducted for the MC measures and two components were identified: 1."Subjective" maternal capital which included stress and depression scores, and 2."Objective" maternal capital which included height, infant birth weight, and verbal memory. Univariate linear regression was conducted to assess the relationship between objective and subjective MC (predictors) and infant growth, infant behavior, maternal behavior, and infant feeding variables (outcomes) at 6-8 weeks. The interaction of MC and intervention assignment with outcomes was assessed. Results Higher objective MC was significantly associated with higher infant weight (0.43; 95%CI 0.21,0.66) and length z-scores (0.47; 95%CI 0.19,0.76), shorter duration of crying (-17.5; 95%CI -33.2,-1.9), and lower food (-0.28; 95%CI -0.48,-0.08) and satiety responsiveness (-0.17; 95%CI -0.31,-0.02) at 6-8 weeks. It was also associated with greater maternal responsiveness to infant cues (-0.05, 95%CI -0.09,-0.02 for non-responsiveness). Greater subjective maternal capital was significantly associated with higher breastfeeding frequency (2.3; 95%CI 0.8,3.8) and infant appetite (0.30; 95%CI 0.07,0.54). There was a significant interaction between the intervention assignment and objective MC for infant length, with trends for infant weight and crying, which indicated that the intervention had greater effects among mothers with lower capital. Conclusion Higher MC was associated with better infant growth and shorter crying duration. This was possibly mediated through more frequent breastfeeding and prompt responsiveness to infant cues, reflecting greater maternal investment. The findings also suggest that a relaxation intervention was most effective among those with low MC, suggesting some reduction in social inequalities in health.
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Affiliation(s)
| | | | - Jonathan C. K. Wells
- Population, Policy and Practice, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
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Hernández-Pacheco R, Steiner UK, Rosati AG, Tuljapurkar S. Advancing methods for the biodemography of aging within social contexts. Neurosci Biobehav Rev 2023; 153:105400. [PMID: 37739326 PMCID: PMC10591901 DOI: 10.1016/j.neubiorev.2023.105400] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 08/10/2023] [Accepted: 09/18/2023] [Indexed: 09/24/2023]
Abstract
Several social dimensions including social integration, status, early-life adversity, and their interactions across the life course can predict health, reproduction, and mortality in humans. Accordingly, the social environment plays a fundamental role in the emergence of phenotypes driving the evolution of aging. Recent work placing human social gradients on a biological continuum with other species provides a useful evolutionary context for aging questions, but there is still a need for a unified evolutionary framework linking health and aging within social contexts. Here, we summarize current challenges to understand the role of the social environment in human life courses. Next, we review recent advances in comparative biodemography and propose a biodemographic perspective to address socially driven health phenotype distributions and their evolutionary consequences using a nonhuman primate population. This new comparative approach uses evolutionary demography to address the joint dynamics of populations, social dimensions, phenotypes, and life history parameters. The long-term goal is to advance our understanding of the link between individual social environments, population-level outcomes, and the evolution of aging.
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Affiliation(s)
- Raisa Hernández-Pacheco
- Department of Biological Sciences, California State University, Long Beach, 1250 N Bellflower Blvd, Long Beach, CA 90840-0004, USA.
| | - Ulrich K Steiner
- Freie Universität Berlin, Biological Institute, Königin-Luise Str. 1-3, 14195 Berlin, Germany
| | - Alexandra G Rosati
- Departments of Psychology and Anthropology, University of Michigan, 530 Church St, Ann Arbor, MI 48109, USA
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6
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Patterson SK, Petersen RM, Brent LJN, Snyder-Mackler N, Lea AJ, Higham JP. Natural Animal Populations as Model Systems for Understanding Early Life Adversity Effects on Aging. Integr Comp Biol 2023; 63:681-692. [PMID: 37279895 PMCID: PMC10503476 DOI: 10.1093/icb/icad058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/25/2023] [Accepted: 05/30/2023] [Indexed: 06/08/2023] Open
Abstract
Adverse experiences in early life are associated with aging-related disease risk and mortality across many species. In humans, confounding factors, as well as the difficulty of directly measuring experiences and outcomes from birth till death, make it challenging to identify how early life adversity impacts aging and health. These challenges can be mitigated, in part, through the study of non-human animals, which are exposed to parallel forms of adversity and can age similarly to humans. Furthermore, studying the links between early life adversity and aging in natural populations of non-human animals provides an excellent opportunity to better understand the social and ecological pressures that shaped the evolution of early life sensitivities. Here, we highlight ongoing and future research directions that we believe will most effectively contribute to our understanding of the evolution of early life sensitivities and their repercussions.
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Affiliation(s)
- Sam K Patterson
- Department of Anthropology, New York University, New York City, 10003, USA
| | - Rachel M Petersen
- Department of Biological Science, Vanderbilt University, Nashville, 37232, USA
| | - Lauren J N Brent
- Department of Psychology, University of Exeter, Exeter, EX4 4QG, United Kingdom
| | - Noah Snyder-Mackler
- School of Life Sciences, Center for Evolution and Medicine, and School of Human Evolution and Social Change, Arizona State University, Tempe, 85281, USA
| | - Amanda J Lea
- Department of Biological Science, Vanderbilt University, Nashville, 37232, USA
- Child and Brain Development Program, Canadian Institute for Advanced Study, Toronto, M5G 1M1, Canada
| | - James P Higham
- Department of Anthropology, New York University, New York City, 10003, USA
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7
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Pittet F, Hinde K. Meager Milk: Lasting Consequences for Adult Daughters of Primiparous Mothers Among Rhesus Macaques (Macaca mulatta). Integr Comp Biol 2023; 63:569-584. [PMID: 37170073 PMCID: PMC10503474 DOI: 10.1093/icb/icad022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 04/21/2023] [Accepted: 04/24/2023] [Indexed: 05/13/2023] Open
Abstract
Among mammals, primipara who initiate reproduction before full maturity can be constrained in their maternal investment, both due to fewer somatic resources and tradeoffs between their own continued development and reproductive effort. Primipara are particularly limited in their capacity to synthesize milk during lactation, the costliest aspect of reproduction for most mammals, especially primates due to long periods of postnatal development. Due to reduced milk transfer, Firstborns may be at elevated risk for long-term consequences of deficits in early life endowment from their primiparous mothers. Here we investigated mass, growth, stature, and lactation performance among N = 273 adult daughters across N = 335 reproductions, who were their own mother's Firstborn or Laterborn progeny, among rhesus macaques (Macaca mulatta) at the California National Primate Research Center. We further explored mass during infancy of the offspring of Firstborn and Laterborn mothers. Firstborns had accelerated growth during infancy, but had slowed growth during juvenility, compared to Laterborns. Although both Firstborns and Laterborns were the same age at reproductive debut, Firstborns had lower body mass, an effect that persisted throughout the reproductive career. Available milk energy, the product of milk energetic density and milk yield, was on average 16% lower for Firstborns compared to Laterborns, a difference that was only partially mediated by their lower mass. Despite differences in their mothers' energy provision through milk, the mass of infants of Firstborn and Laterborn mothers did not differ at peak lactation, suggesting that infants of Firstborns devote a higher proportion of milk energy to growth than infants of Laterborns. To date few studies have explored how early life conditions shape capacities to synthesize milk and milk composition. Our findings contribute new information among primates on how early life maternal endowments are associated with persistent effects long after the period of maternal dependence well into reproductive maturity.
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Affiliation(s)
- Florent Pittet
- Neuroscience and Behavior Unit, California National Primate Research Center, University of California, Davis, CA 95616, USA
| | - Katie Hinde
- School of Human Evolution and Social Change, Tempe, AZ 85287, USA
- Center for Evolution and Medicine, Arizona State University, Tempe, AZ 85287, USA
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8
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Dettmer AM, Chusyd DE. Early life adversities and lifelong health outcomes: A review of the literature on large, social, long-lived nonhuman mammals. Neurosci Biobehav Rev 2023; 152:105297. [PMID: 37391110 PMCID: PMC10529948 DOI: 10.1016/j.neubiorev.2023.105297] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/02/2023]
Abstract
Social nonhuman animals are powerful models for studying underlying factors related to lifelong health outcomes following early life adversities (ELAs). ELAs can be linked to lifelong health outcomes depending on the species, system, sensitive developmental periods, and biological pathways. This review focuses on the literature surrounding ELAs and lifelong health outcomes in large, social, relatively long-lived nonhuman mammals including nonhuman primates, canids, hyenas, elephants, ungulates, and cetaceans. These mammals, like humans but unlike the most-studied rodent models, have longer life histories, complex social structures, larger brains, and comparable stress and reproductive physiology. Collectively, these features make them compelling models for comparative aging research. We review studies of caregiver, social, and ecological ELAs, often in tandem, in these mammals. We consider experimental and observational studies and what each has contributed to our knowledge of health across the lifespan. We demonstrate the continued and expanded need for comparative research to inform about the social determinants of health and aging in both humans and nonhuman animals.
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Affiliation(s)
- Amanda M Dettmer
- Yale Child Study Center, Yale School of Medicine, 230 S. Frontage Rd., New Haven, CT, USA.
| | - Daniella E Chusyd
- Department of Environmental and Occupational Health, Indiana University Bloomington, 1025 E. 7th St., Bloomington, IN, USA; Department of Health and Wellness Design, Indiana University Bloomington, 1025 E. 7th St., Bloomington, IN, USA
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9
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Tung J, Lange EC, Alberts SC, Archie EA. Social and early life determinants of survival from cradle to grave: A case study in wild baboons. Neurosci Biobehav Rev 2023; 152:105282. [PMID: 37321362 PMCID: PMC10529797 DOI: 10.1016/j.neubiorev.2023.105282] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 06/06/2023] [Accepted: 06/10/2023] [Indexed: 06/17/2023]
Abstract
Field studies of natural mammal populations present powerful opportunities to investigate the determinants of health and aging using fine-grained observations of known individuals across the life course. Here, we synthesize five decades of findings from one such study: the wild baboons of the Amboseli ecosystem in Kenya. First, we discuss the profound associations between early life adversity, adult social conditions, and key aging outcomes in this population, especially survival. Second, we review potential mediators of the relationship between early life adversity and survival in our population. Notably, our tests of two leading candidate mediators-social isolation and glucocorticoid levels-fail to identify a single, strong mediator of early life effects on adult survival. Instead, early adversity, social isolation, and glucocorticoids are independently linked to adult lifespans, suggesting considerable scope for mitigating the negative consequences of early life adversity. Third, we review our work on the evolutionary rationale for early life effects on mortality, which currently argues against clear predictive adaptive responses. Finally, we end by highlighting major themes emerging from the study of sociality, development, and aging in the Amboseli baboons, as well as important open questions for future work.
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Affiliation(s)
- Jenny Tung
- Department of Primate Behavior and Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany; Department of Evolutionary Anthropology, Duke University, Durham, NC, USA; Department of Biology, Duke University, Durham NC, USA; Canadian Institute for Advanced Research, Toronto, Canada; Duke Population Research Institute, Duke University, Durham, NC, USA.
| | - Elizabeth C Lange
- Department of Biology, Duke University, Durham NC, USA; Department of Biological Sciences, State University of New York at Oswego, Oswego, NY, USA
| | - Susan C Alberts
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA; Department of Biology, Duke University, Durham NC, USA; Duke Population Research Institute, Duke University, Durham, NC, USA
| | - Elizabeth A Archie
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, USA
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10
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Patterson SK, Andonov E, Arre AM, Martínez MI, Negron-Del Valle JE, Petersen RM, Phillips D, Rahman A, Ruiz-Lambides A, Villanueva I, Lea AJ, Snyder-Mackler N, Brent LJ, Higham JP. Early life adversity has sex-dependent effects on survival across the lifespan in rhesus macaques. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.30.555589. [PMID: 37693423 PMCID: PMC10491187 DOI: 10.1101/2023.08.30.555589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Exposure to adversity during early life is linked to lasting detrimental effects on evolutionary fitness across many taxa. However, due to the challenges of collecting longitudinal data, especially in species where one sex disperses, direct evidence from long-lived species remains relatively scarce. Here we test the effects of early life adversity on male and female longevity in a free-ranging population of rhesus macaques (Macaca mulatta) at Cayo Santiago, Puerto Rico. We leveraged six decades of data to quantify the relative importance of ten forms of early life adversity for 6,599 macaques (3,230 male, 3,369 female), with a smaller sample size (N=299) for one form of adversity (maternal social isolation) which required high-resolution behavioral data. We found that individuals who experienced more early life adversity died earlier than those who experienced less adversity. Mortality risk was highest during early life, defined as birth to four years old, suggesting acute survival effects of adversity, but heightened mortality risk was also present in macaques who survived to adulthood. Females and males were affected differently by some forms of adversity, and these differences might be driven by varying energetic demands, female philopatry, and male dispersal. By leveraging data on thousands of macaques collected over decades, our results show that the fitness consequences of early life adversity are not uniform across individuals but vary as a function of the type of adversity, timing, and social context, and thus contribute to our limited but growing understanding of the evolution of early life sensitivities in long-lived species.
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Affiliation(s)
| | - Ella Andonov
- High School of American Studies at Lehman College, New York City
| | - Alyssa M. Arre
- Caribbean Primate Research Center, Unit of Comparative Medicine, University of Puerto Rico
| | - Melween I. Martínez
- Caribbean Primate Research Center, Unit of Comparative Medicine, University of Puerto Rico
| | | | | | | | | | - Angelina Ruiz-Lambides
- Caribbean Primate Research Center, Unit of Comparative Medicine, University of Puerto Rico
| | | | - Amanda J. Lea
- Department of Biological Science, Vanderbilt University
- Child and Brain Development Program, Canadian Institute for Advanced Study, Toronto, Canada
| | - Noah Snyder-Mackler
- Center for Evolution and Medicine, Arizona State University
- School of Life Sciences and School of Human Evolution and Social Change, Arizona State University
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11
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Smith JE, Natterson-Horowitz B, Mueller MM, Alfaro ME. Mechanisms of equality and inequality in mammalian societies. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220307. [PMID: 37381860 DOI: 10.1098/rstb.2022.0307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/09/2023] [Indexed: 06/30/2023] Open
Abstract
The extent of (in)equality is highly diverse across species of social mammals, but we have a poor understanding of the factors that produce or inhibit equitable social organizations. Here, we adopt a comparative evolutionary perspective to test whether the evolution of social dominance hierarchies, a measure of social inequality in animals, exhibits phylogenetic conservatism and whether interspecific variation in these traits can be explained by sex, age or captivity. We find that hierarchy steepness and directional consistency evolve rapidly without any apparent constraint from evolutionary history. Given this extraordinary variability, we next consider multiple factors that have evolved to mitigate social inequality. Social networks, coalitionary support and knowledge transfer advantage to privilege some individuals over others. Nutritional access and prenatal stressors can impact the development of offspring, generating health disparities with intergenerational consequences. Intergenerational transfer of material resources (e.g. stone tools, food stashes, territories) advantage those who receive. Nonetheless, many of the same social species that experience unequal access to food (survival) and mates (reproduction) engage in levelling mechanisms such as food sharing, adoption, revolutionary coalitions, forgiveness and inequity aversion. Taken together, mammals rely upon a suite of mechanisms of (in)equality to balance the costs and benefits of group living. This article is part of the theme issue 'Evolutionary ecology of inequality'.
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Affiliation(s)
- Jennifer E Smith
- Biology Department, University of Wisconsin Eau Claire, 105 Garfield Avenue, Eau Claire, WI 54702, USA
| | - Barbara Natterson-Horowitz
- School of Medicine, Division of Cardiology, University of California, 650 Charles Young Drive South, A2-237 CHS, Los Angeles, CA 90095, USA
| | - Maddison M Mueller
- Biology Department, University of Wisconsin Eau Claire, 105 Garfield Avenue, Eau Claire, WI 54702, USA
| | - Michael E Alfaro
- Department of Ecology and Evolutionary Biology, University of California, 2149 Terasaki Life Sciences Building, 612 Charles E. Young Drive South, Box 957246, Los Angeles, CA 90095-7246, USA
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12
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Morrison RE, Eckardt W, Stoinski TS, Rosenbaum S. Cumulative early-life adversity does not predict reduced adult longevity in wild gorillas. Curr Biol 2023; 33:2307-2314.e4. [PMID: 37192615 PMCID: PMC10264970 DOI: 10.1016/j.cub.2023.04.051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/24/2023] [Accepted: 04/21/2023] [Indexed: 05/18/2023]
Abstract
Extensive research across fields has repeatedly confirmed that early-life adversity (ELA) is a major selective force for many taxa, in part via its ties to adult health and longevity.1,2,3 Negative effects of ELA on adult outcomes have been documented in a wide range of species, from fish to birds to humans.4 We used 55 years of long-term data collected on 253 wild mountain gorillas to examine the effects of six putative sources of ELA on survival, both individually and cumulatively. Although cumulative ELA was associated with high mortality in early life, we found no evidence that it had detrimental consequences for survival later in life. Experiencing three or more forms of ELA was associated with greater longevity, with a 70% reduction in the risk of death across adulthood, driven specifically by greater longevity in males. Although this higher survival in later life is likely a consequence of sex-specific viability selection5 during early life due to the immediate mortality consequences of adverse experiences, patterns in our data also suggest that gorillas have significant resilience to ELA. Our findings demonstrate that the detrimental consequences of ELA on later life survival are not universal, and indeed largely absent in one of humans' closest living relatives. This raises important questions about the biological roots of sensitivity to early experiences and the protective mechanisms that contribute to resiliency in gorillas, which could be critical for understanding how best to encourage similar resiliency to early-life shocks in humans.
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Affiliation(s)
- Robin E Morrison
- Dian Fossey Gorilla Fund, PO Box 105, Musanze, Rwanda; Centre for Research in Animal Behaviour, Department of Psychology, University of Exeter, Exeter EX4 4QG, UK.
| | | | | | - Stacy Rosenbaum
- Department of Anthropology, University of Michigan-Ann Arbor, Ann Arbor, MI 48109, USA.
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Frankenhuis WE, Amir D. What is the expected human childhood? Insights from evolutionary anthropology. Dev Psychopathol 2022; 34:473-497. [PMID: 34924077 DOI: 10.1017/s0954579421001401] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In psychological research, there are often assumptions about the conditions that children expect to encounter during their development. These assumptions shape prevailing ideas about the experiences that children are capable of adjusting to, and whether their responses are viewed as impairments or adaptations. Specifically, the expected childhood is often depicted as nurturing and safe, and characterized by high levels of caregiver investment. Here, we synthesize evidence from history, anthropology, and primatology to challenge this view. We integrate the findings of systematic reviews, meta-analyses, and cross-cultural investigations on three forms of threat (infanticide, violent conflict, and predation) and three forms of deprivation (social, cognitive, and nutritional) that children have faced throughout human evolution. Our results show that mean levels of threat and deprivation were higher than is typical in industrialized societies, and that our species has experienced much variation in the levels of these adversities across space and time. These conditions likely favored a high degree of phenotypic plasticity, or the ability to tailor development to different conditions. This body of evidence has implications for recognizing developmental adaptations to adversity, for cultural variation in responses to adverse experiences, and for definitions of adversity and deprivation as deviation from the expected human childhood.
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Affiliation(s)
- Willem E Frankenhuis
- Department of Psychology, Utrecht University, Utrecht, the Netherlands
- Max Planck Institute for the Study of Crime, Security and Law, Germany
| | - Dorsa Amir
- Department of Psychology, Boston College, Chestnut Hill, USA
- Department of Psychology, University of California, Berkeley, USA
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Bădescu I, Watts DP, Katzenberg MA, Sellen DW. Maternal lactational investment is higher for sons in chimpanzees. Behav Ecol Sociobiol 2022. [DOI: 10.1007/s00265-022-03153-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Abstract
Maternal lactational investment can affect female reproductive rates and offspring survival in mammals and can be biased towards infants of one sex. We compared estimates of lactation effort among mothers, assessed as their potential milk contribution to age-specific infant diets (mother-infant differences in fecal stable nitrogen isotopes, δ15N), to the timing of weaning (infant age at last nursing bout) and to maternal inter-birth interval lengths for male and female infant chimpanzees (Pan troglodytes) at Ngogo, Uganda. Infant males had greater proportions of milk in their age-specific diets, indicated by higher mother-infant differences in δ15N (Generalized Estimating Equation, GEE: p < 0.01). This may mean that mothers of sons showed greater lactation effort than mothers of daughters. Infant males stopped nursing at older ages than infant females (Kaplan–Meier product limit estimate, Breslow estimator: p < 0.05). Mothers of sons showed longer interbirth intervals than mothers of daughters (GEE: p < 0.01). All three measures indicated maternal lactational investment was higher for sons. Male infants may cost mothers more to ensure infant survival than female infants because males are more vulnerable and/or because maternal genetic returns on investment are greater for sons than daughters, as male philopatry means that chimpanzee mothers can have more influence on the reproductive success of sons. Chimpanzee females may trade off growth-related benefits of high lactational investment in male offspring against reduced reproductive rates.
Significance statement
Maternal investment via lactation affects the reproductive success of female mammals and their offspring and can be biased towards infants of one sex. We investigated lactational variation among wild chimpanzees in relation to infant sex using three proxies for maternal lactational investment: fecal stable nitrogen isotopes, a physiological biomarker that may provide an estimate of lactation effort; observations of nursing, which we used to establish weaning ages; and the lengths of intervals between births of surviving infants. Chimpanzee mothers biased lactational investment toward sons on all three indicators and showed reduced fecundity due to longer inter-birth intervals for mothers of sons than for mothers of daughters. These results would be expected if greater maternal investment toward sons leads to better condition and higher reproductive success for sons later in life, thus to greater inclusive fitness for mothers.
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Patterson SK, Strum SC, Silk JB. Early life adversity has long-term effects on sociality and interaction style in female baboons. Proc Biol Sci 2022; 289:20212244. [PMID: 35105243 PMCID: PMC8808103 DOI: 10.1098/rspb.2021.2244] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Social bonds enhance fitness in many group-living animals, generating interest in the processes that create individual variation in sociality. Previous work on female baboons shows that early life adversity and temperament both influence social connectedness in adulthood. Early life adversity might shape sociality by reducing ability to invest in social relationships or through effects on attractiveness as a social partner. We examine how females' early life adversity predicts sociality and temperament in wild olive baboons, and evaluate whether temperament mediates the relationship between early life adversity and sociality. We use behavioural data on 31 females to quantify sociality. We measure interaction style as the tendency to produce grunts (signals of benign intent) in contexts in which the vocalization does not produce immediate benefits to the actor. Early life adversity was negatively correlated with overall sociality, but was a stronger predictor of social behaviours received than behaviours initiated. Females who experienced less early life adversity had more benign interaction styles and benign interaction styles were associated with receiving more social behaviours. Interaction style may partially mediate the association between early life adversity and sociality. These analyses add to our growing understanding of the processes connecting early life experiences to adult sociality.
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Affiliation(s)
- Sam K. Patterson
- Department of Anthropology, New York University, New York, NY, USA
| | - Shirley C. Strum
- Department of Anthropology, University of California, San Diego, CA, USA,Uaso Ngiro Baboon Project, Nairobi, Kenya
| | - Joan B. Silk
- School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA,Institute for Human Origins, Arizona State University, Tempe, AZ, USA
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Malalaharivony HS, Fichtel C, Heistermann M, Kappeler PM. Maternal stress effects on infant development in wild Verreaux's sifaka (Propithecus verreauxi). Behav Ecol Sociobiol 2021. [DOI: 10.1007/s00265-021-03085-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Abstract
Maternal effects mediated by nutrients or specific endocrine states of the mother can affect infant development. Specifically, pre- and postnatal maternal stress associated with elevated glucocorticoid (GC) output is known to influence the phenotype of the offspring, including their physical and behavioral development. These developmental processes, however, remain relatively poorly studied in wild vertebrates, including primates with their relatively slow life histories. Here, we investigated the effects of maternal stress, assessed by fecal glucocorticoid output, on infant development in wild Verreaux’s sifakas (Propithecus verreauxi), a group-living Malagasy primate. In a first step, we investigated factors predicting maternal fecal glucocorticoid metabolite (fGCM) concentrations, how they impact infants’ physical and behavioral development during the first 6 months of postnatal life as well as early survival during the first 1.5 years of postnatal life. We collected fecal samples of mothers for hormone assays and behavioral data of 12 infants from two birth cohorts, for which we also assessed growth rates. Maternal fGCM concentrations were higher during the late prenatal but lower during the postnatal period compared to the early/mid prenatal period and were higher during periods of low rainfall. Infants of mothers with higher prenatal fGCM concentrations exhibited faster growth rates and were more explorative in terms of independent foraging and play. Infants of mothers with high pre- and postnatal fGCM concentrations were carried less and spent more time in nipple contact. Time mothers spent carrying infants predicted infant survival: infants that were more carried had lower survival, suggesting that they were likely in poorer condition and had to be cared for longer. Thus, the physical and behavioral development of these young primates were impacted by variation in maternal fGCM concentrations during the first 6 months of their lives, presumably as an adaptive response to living in a highly seasonal, but unpredictable environment.
Significance statement
The early development of infants can be impacted by variation in maternal condition. These maternal effects can be mediated by maternal stress (glucocorticoid hormones) and are known to have downstream consequences for behavior, physiology, survival, and reproductive success well into adulthood. However, the direction of the effects of maternal physiological GC output on offspring development is highly variable, even within the same species. We contribute comparative data on maternal stress effects on infant development in a Critically Endangered primate from Madagascar. We describe variation in maternal glucocorticoid output as a function of ecological and reproductive factors and show that patterns of infant growth, behavioral development, and early survival are predicted by maternal glucocorticoids. Our study demonstrates how mothers can influence offspring fitness in response to challenging environmental conditions.
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