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Finlay BL, Huang K. Developmental duration as an organizer of the evolving mammalian brain: scaling, adaptations, and exceptions. Evol Dev 2019; 22:181-195. [PMID: 31794147 DOI: 10.1111/ede.12329] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neurodevelopmental duration plays a central role in the evolution of the retina and neocortex in mammals. In the diurnal primate eye and retina, it is necessary to scale the number of cones versus the number of rods with different exponents to defend their respective functions of spatial acuity and sensitivity in eyes of different sizes. The order of photoreceptor precursor specification, cones specified first, rods second, couples their respective cell numbers at maturity to the kinetics of embryonic stem cell proliferation. Different durations of retinogenesis change the ratio of rods to cones produced so as to defend both functions over a range of eye diameters. In the evolution of nocturnality, the same coupling of photoreceptor specification to neurogenesis is altered to fewer cones and many more rods in nocturnal eyes, by delaying the onset of retinogenesis. Similarly, the neocortex also shows coupling of the specification of laminar position with duration of neurogenesis. Overall, duration of neurogenesis directly predicts neocortex volume in most mammalian clades. In larger brains with longer neocortical neurogenesis, its organization changes progressively, differentiating the frontal pole from the occipital pole in volume of connectivity and number of neurons per unit column. This permits greater, hierarchically organized information abstraction with increasing neocortex volume. Exceptions do exist, however, in species of three separate taxa, marsupials, naked mole rats, and bats, which break the correlation of neurodevelopmental duration and brain size. Naked mole rats and bats both have small brains and unusual longevity, coupled with neurodevelopmental periods characteristic of much bigger-brained animals, raising the possibility that developmental duration and lifespan have some genetic or mechanistic control in common. The role of duration of development in mediating between the mechanistic levels of construction of retinal and cortical organization, and the different life histories associated with larger brains, such as duration of parental care, learning and overall longevity are discussed.
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Affiliation(s)
- Barbara L Finlay
- Behavioral and Evolutionary Science Group, Department of Psychology, Cornell University, Ithaca, New York
| | - Kexin Huang
- Institute for Advanced Research, Shanghai, China
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New approaches to modeling primate socioecology: Does small female group size BEGET loyal males? J Hum Evol 2019; 137:102671. [DOI: 10.1016/j.jhevol.2019.102671] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 07/09/2019] [Accepted: 07/16/2019] [Indexed: 12/13/2022]
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Singletary B. What are the benefits of having a village? Effects of allomaternal care on communicative skills in early infancy. Infant Behav Dev 2019; 57:101361. [PMID: 31491616 DOI: 10.1016/j.infbeh.2019.101361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/31/2019] [Accepted: 08/20/2019] [Indexed: 11/19/2022]
Abstract
This study investigates whether exposure to allomaternal care (AMC-care for infants from individuals other than the mother) improves rates of communicative behaviors during late infancy by providing more opportunities to practice communicating with varied caregivers. Data were collected from 102 typically-developing infants aged 13-18 months and their mothers. AMC variables were collected using a current care questionnaire, structured 14-day diary, and longitudinal interview. Communicative behaviors were assessed through post hoc microcoding of in-lab administrations of the Early Social Communication Scales (ESCS), as well as additional microcoding of the Bayley III Screening Cognitive Subtest. Demographic covariates were also included. For each communicative behavior, backward model selection was used to determine the best fitting linear regression model. Results suggested that rates of turn-taking decreased with Household AMC (p < 0.008), but increased with two or more siblings present at home (p < 0.01). Conversely, rates of spontaneous giving increased with Household AMC (p < 0.003) regardless of the presence of siblings. Notably, exposure to more AMC was neither helpful nor harmful for many of the tested communicative behaviors, although the number of siblings present was significantly related to rates of following commands, as well as pointing and reaching. Ultimately, this study suggests that household level experiences with AMC, rather than formalized care, impact the development of some communicative behaviors during late infancy.
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Affiliation(s)
- Britt Singletary
- School of Anthropology, University of Arizona, 1009 East South Campus Dr., P.O. Box 210030, Tucson, AZ 85721-0030, United States.
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54
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Finlay B. Generic Homo sapiens and Unique Mus musculus: Establishing the Typicality of the Modeled and the Model Species. BRAIN, BEHAVIOR AND EVOLUTION 2019; 93:122-136. [DOI: 10.1159/000500111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/02/2019] [Indexed: 11/19/2022]
Abstract
The question of how complex human abilities evolved, such as language or face recognition, has been pursued by means of multiple strategies. Highly specialized non-human species have been examined analytically for formal similarities, close phylogenetic relatives have been examined for continuity, and simpler species have been analyzed for the broadest view of functional organization. All these strategies require empirical evidence of what is variable and predictable in both the modeled and the model species. Turning to humans, allometric analyses of the evolution of brain mass and brain components often return the interesting, but disappointing answer that volumetric organization of the human brain is highly predictable seen in its phylogenetic context. Reconciling this insight with unique human behavior, or any species-typical behavior, represents a serious challenge. Allometric analyses of the order and duration of mammalian neural development show that, while basic neural development in humans is allometrically predictable, conforming to adult neural architecture, some life history features deviate, notably that weaning is unusually early. Finally, unusual deviations in the retina and central auditory system in the laboratory mouse, which is widely assumed to be “generic,” as well as severe deviations from expected brain allometry in some mouse strains, underline the need for a deeper understanding of phylogenetic variability even in those systems believed to be best understood.
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Williams AC, Hill LJ. Nicotinamide as Independent Variable for Intelligence, Fertility, and Health: Origin of Human Creative Explosions? Int J Tryptophan Res 2019; 12:1178646919855944. [PMID: 31258332 PMCID: PMC6585247 DOI: 10.1177/1178646919855944] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 05/03/2019] [Indexed: 12/28/2022] Open
Abstract
Meat and nicotinamide acquisition was a defining force during the 2-million-year evolution of the big brains necessary for, anatomically modern, Homo sapiens to survive. Our next move was down the food chain during the Mesolithic 'broad spectrum', then horticultural, followed by the Neolithic agricultural revolutions and progressively lower average 'doses' of nicotinamide. We speculate that a fertility crisis and population bottleneck around 40 000 years ago, at the time of the Last Glacial Maximum, was overcome by Homo (but not the Neanderthals) by concerted dietary change plus profertility genes and intense sexual selection culminating in behaviourally modern Homo sapiens. Increased reliance on the 'de novo' synthesis of nicotinamide from tryptophan conditioned the immune system to welcome symbionts, such as TB (that excrete nicotinamide), and to increase tolerance of the foetus and thereby fertility. The trade-offs during the warmer Holocene were physical and mental stunting and more infectious diseases and population booms and busts. Higher nicotinamide exposure could be responsible for recent demographic and epidemiological transitions to lower fertility and higher longevity, but with more degenerative and auto-immune disease.
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Affiliation(s)
- Adrian C Williams
- Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Lisa J Hill
- School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
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Affiliation(s)
- Joseph Robert Burger
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
- North Carolina Museum of Natural Sciences, Raleigh, NC, USA
| | | | - Claire Leadbetter
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
| | - Farhin Shaikh
- Department of Biology, University of North Carolina, Chapel Hill, NC, USA
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Xiang Z, Fan P, Chen H, Liu R, Zhang B, Yang W, Yao H, Grueter CC, Garber PA, Li M. Routine allomaternal nursing in a free-ranging Old World monkey. SCIENCE ADVANCES 2019; 5:eaav0499. [PMID: 30801014 PMCID: PMC6382398 DOI: 10.1126/sciadv.aav0499] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 01/10/2019] [Indexed: 06/09/2023]
Abstract
While regular allomaternal nursing (suckling) has been documented in a number of rodent and carnivore species, as well as in some prosimians, New World monkeys, and humans, it is not common in Old World monkeys and apes. Here, we present a detailed field study of allomaternal nursing in golden snub-nosed monkeys (Rhinopithecus roxellana, Colobinae). We found that more than 87% of infants were nursed by females other than their mothers. Allomaternal nursing was largely confined to the first 3 months of an infant's life and occurred predominantly between related females who nursed each other's offspring in a reciprocal manner. Allomaternal nursing enhanced infant survivorship and did not have a negative impact on the future reproductive success of allonursers. Our findings expand the taxonomic distribution of allomaternal nursing and provide fresh insight into the possible factors driving evolution of allomaternal nursing behavior in primates, including humans.
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Affiliation(s)
- Zuofu Xiang
- College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute of Evolutionary Ecology and Conservation Biology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Penglai Fan
- Institute of Evolutionary Ecology and Conservation Biology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Haochun Chen
- College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Ruoshuang Liu
- College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Bo Zhang
- College of Life Science and Technology, Central South University of Forestry and Technology, Changsha, Hunan 410004, China
| | - Wanji Yang
- Key Laboratory of Conservation Biology for Shennongjia Golden Monkey, Hubei Province, Shennongjia Forest District, Hubei 442411, China
| | - Hui Yao
- Key Laboratory of Conservation Biology for Shennongjia Golden Monkey, Hubei Province, Shennongjia Forest District, Hubei 442411, China
| | - Cyril C. Grueter
- School of Human Sciences, The University of Western Australia, Crawley, WA 6009, Australia
| | - Paul A. Garber
- Department of Anthropology Program in Ecology and Evolutionary Biology, University of Illinois, Urbana, IL 61801, USA
| | - Ming Li
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
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Hill T, Polk JD. BDNF, endurance activity, and mechanisms underlying the evolution of hominin brains. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 168 Suppl 67:47-62. [PMID: 30575024 DOI: 10.1002/ajpa.23762] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 10/21/2018] [Accepted: 11/05/2018] [Indexed: 12/12/2022]
Abstract
OBJECTIVES As a complex, polygenic trait, brain size has likely been influenced by a range of direct and indirect selection pressures for both cognitive and non-cognitive functions and capabilities. It has been hypothesized that hominin brain expansion was, in part, a correlated response to selection acting on aerobic capacity (Raichlen & Polk, 2013). According to this hypothesis, selection for aerobic capacity increased the activity of various signaling molecules, including those involved in brain growth. One key molecule is brain-derived neurotrophic factor (BDNF), a protein that regulates neuronal development, survival, and plasticity in mammals. This review updates, partially tests, and expands Raichlen and Polk's (2013) hypothesis by evaluating evidence for BDNF as a mediator of brain size. DISCUSSION We contend that selection for endurance capabilities in a hot climate favored changes to muscle composition, mitochondrial dynamics and increased energy budget through pathways involving regulation of PGC-1α and MEF2 genes, both of which promote BDNF activity. In addition, the evolution of hairlessness and the skin's thermoregulatory response provide other molecular pathways that promote both BDNF activity and neurotransmitter synthesis. We discuss how these pathways contributed to the evolution of brain size and function in human evolution and propose avenues for future research. Our results support Raichlen and Polk's contention that selection for non-cognitive functions has direct mechanistic linkages to the evolution of brain size in hominins.
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Affiliation(s)
- Tyler Hill
- Department of Anthropology, University of Illinois Urbana-Champaign, Urbana, Illinois
| | - John D Polk
- Department of Anthropology, University of Illinois Urbana-Champaign, Urbana, Illinois.,Department of Biomedical and Translational Sciences, Carle-Illinois College of Medicine, Urbana, Illinois
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60
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DeCasien AR, Thompson NA, Williams SA, Shattuck MR. Encephalization and longevity evolved in a correlated fashion in Euarchontoglires but not in other mammals. Evolution 2018; 72:2617-2631. [DOI: 10.1111/evo.13633] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 10/18/2018] [Accepted: 10/23/2018] [Indexed: 12/23/2022]
Affiliation(s)
- Alex R. DeCasien
- Department of Anthropology New York University New York New York 10003
- New York Consortium in Evolutionary Primatology New York New York 10024
| | - Nicole A. Thompson
- New York Consortium in Evolutionary Primatology New York New York 10024
- Department of Ecology, Evolution, and Environmental Biology Columbia University New York New York 10027
| | - Scott A. Williams
- Department of Anthropology New York University New York New York 10003
- New York Consortium in Evolutionary Primatology New York New York 10024
| | - Milena R. Shattuck
- Department of Anthropology and Program of Human Biology Hunter College, CUNY New York New York 10065
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61
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The degree of altriciality and performance in a cognitive task show correlated evolution. PLoS One 2018; 13:e0205128. [PMID: 30300365 PMCID: PMC6177164 DOI: 10.1371/journal.pone.0205128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 09/19/2018] [Indexed: 11/19/2022] Open
Abstract
Previous comparative research on the evolution of cognition has tested what we call the “altricial intelligence hypothesis”. This posits that a relationship between evolutionary changes in the altricial period length and cognition exists across animal species. However, the evidence available thus far either comes from indirect measurements of cognition or has not been conclusive. We performed a phylogenetic analysis of published data from various sources on 31 homeothermic species to test for an evolutionary association between the degree of altriciality and a direct measure of self-control. For each species, the degree of altriciality was determined based on the residual altricial period (i.e., the time from birth to fledging in birds and to weaning in mammals) on lifespan. The percentage of success in the cylinder task was the measure of self-control. Our results showed that the degree of altriciality covaried positively with the measure of self-control. Based on the results of this study, we sustain that evolutionary changes in the length of the altricial period are associated with evolutionary changes in the cognitive system used by homeotherms to perform the cylinder task.
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62
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You W, Rühli FJ, Henneberg RJ, Henneberg M. Greater family size is associated with less cancer risk: an ecological analysis of 178 countries. BMC Cancer 2018; 18:924. [PMID: 30257658 PMCID: PMC6156945 DOI: 10.1186/s12885-018-4837-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 09/19/2018] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Greater family size measured with total fertility rate (TFR) and with household size, may offer more life satisfaction to the family members. Positive psychological well-being has been postulated to decrease cancer initiation risk. This ecological study aims to examine the worldwide correlation between family size, used as the measure of positive psychological well-being, and total cancer incidence rates. METHODS Country specific estimates obtained from United Nations agencies on total cancer incidence rates (total, female and male rates in age range 0-49 years and all ages respectively), all ages site cancer incidence (bladder, breast, cervix uteri, colorectum, corpus uteri, lung, ovary and stomach), TFR, household size, life expectancy, urbanization, per capita GDP PPP and self-calculated Biological State Index (Ibs) were matched for data analysis. Pearson's, non-parametric Spearman's, partial correlations, independent T-test and multivariate regressions were conducted in SPSS. RESULTS Worldwide, TFR and household size were significantly and negatively correlated to all the cancer incidence variables. These correlations remained significant in partial correlation analysis when GDP, life expectancy, Ibs and urbanization were controlled for. TFR correlated to male cancer incidence rate (all ages) significantly stronger than it did to female cancer incidence rate (all ages) in both Pearson's and partial correlations. Multivariate stepwise regression analysis indicated that TFR and household size were consistently significant predictors of all cancer incidence variables. CONCLUSIONS Countries with greater family size have lower cancer risk in both females, and especially males. Our results seem to suggest that it may be worthwhile further examining correlations between family size and cancer risk in males and females through the cohort and case-control studies based on large samples.
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Affiliation(s)
- Wenpeng You
- Adelaide Medical School, The University of Adelaide, Adelaide, SA 5005 Australia
| | - Frank J Rühli
- Institute of Evolutionary Medicine, University of Zurich, Zürich, Switzerland
| | - Renata J Henneberg
- Biological Anthropology and Comparative Anatomy Unit, Adelaide Medical School, The University of Adelaide, Adelaide, Australia
| | - Maciej Henneberg
- Adelaide Medical School, The University of Adelaide, Adelaide, SA 5005 Australia
- Institute of Evolutionary Medicine, University of Zurich, Zürich, Switzerland
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63
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Physiological mechanisms mediating patterns of reproductive suppression and alloparental care in cooperatively breeding carnivores. Physiol Behav 2018; 193:167-178. [DOI: 10.1016/j.physbeh.2017.11.006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 10/14/2017] [Accepted: 11/06/2017] [Indexed: 12/17/2022]
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64
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Hawkes K, Finlay BL. Mammalian brain development and our grandmothering life history. Physiol Behav 2018; 193:55-68. [DOI: 10.1016/j.physbeh.2018.01.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 01/15/2018] [Accepted: 01/16/2018] [Indexed: 11/28/2022]
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65
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Boose K, White F, Brand C, Meinelt A, Snodgrass J. Infant handling in bonobos (Pan paniscus): Exploring functional hypotheses and the relationship to oxytocin. Physiol Behav 2018; 193:154-166. [DOI: 10.1016/j.physbeh.2018.04.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 04/08/2018] [Accepted: 04/09/2018] [Indexed: 12/26/2022]
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66
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Tecot SR, Baden AL. Profiling caregivers: Hormonal variation underlying allomaternal care in wild red-bellied lemurs, Eulemur rubriventer. Physiol Behav 2018; 193:135-148. [DOI: 10.1016/j.physbeh.2017.12.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 12/05/2017] [Accepted: 12/05/2017] [Indexed: 01/31/2023]
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67
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Heldstab SA, Isler K, van Schaik CP. Hibernation constrains brain size evolution in mammals. J Evol Biol 2018; 31:1582-1588. [PMID: 30030877 DOI: 10.1111/jeb.13353] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/09/2018] [Accepted: 07/16/2018] [Indexed: 12/22/2022]
Abstract
The expensive brain hypothesis predicts that the lowest stable level of steady energy input acts as a strong constraint on a species' brain size, and thus, that periodic troughs in net energy intake should select for reduced brain size relative to body mass. Here, we test this prediction for the extreme case of hibernation. Hibernators drastically reduce food intake for up to several months and are therefore expected to have smaller relative brain sizes than nonhibernating species. Using a comparative phylogenetic approach on brain size estimates of 1104 mammalian species, and controlling for possible confounding variables, we indeed found that the presence of hibernation in mammals is correlated with decreased relative brain size. This result adds to recent comparative work across mammals and amphibians supporting the idea that environmental seasonality (where in extremis hibernation is necessary for survival) imposes an energetic challenge and thus acts as an evolutionary constraint on relative brain size.
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Affiliation(s)
- Sandra A Heldstab
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Karin Isler
- Department of Anthropology, University of Zurich, Zurich, Switzerland
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Burkart JM, van Schaik C, Griesser M. Looking for unity in diversity: human cooperative childcare in comparative perspective. Proc Biol Sci 2018; 284:rspb.2017.1184. [PMID: 29237848 DOI: 10.1098/rspb.2017.1184] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 11/13/2017] [Indexed: 01/31/2023] Open
Abstract
Humans engage in cooperative childcare, which includes some elements not found in other animals, such as the presence of post-reproductive helpers, extensive food sharing among adults and a pervasive sexual division of labour. In animals, cooperative offspring care has typically been studied in two different contexts. The first mainly involves helpers contributing care in cooperatively breeding family groups; the second context is allomaternal care in species usually not categorized as cooperative breeders (e.g. plural and communal breeders, often without male care). Comparative analyses suggest that cooperative breeding and allomaternal care in plural and communal breeders have distinct evolutionary origins, with humans fitting neither pathway entirely. Nevertheless, some critical proximate mechanisms of helping, including hormonal regulators, are likely to be shared across species. Other mechanisms may vary among species, such as social tolerance, proactive prosociality or conditional mother-infant bonding. These are presumably associated with specific details of the care system, such as whether all group members contribute, or whether mothers can potentially raise offspring alone. Thus, cooperative offspring care is seen in different contexts across animal lineages, but may nonetheless share several important psychological characteristics. We end by discussing how work on humans may play a unifying role in studying cooperative offspring care.
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Affiliation(s)
- Judith M Burkart
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Carel van Schaik
- Department of Anthropology, University of Zurich, Zurich, Switzerland
| | - Michael Griesser
- Department of Anthropology, University of Zurich, Zurich, Switzerland.,Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, Krakow 30-387, Poland
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Sociality does not drive the evolution of large brains in eusocial African mole-rats. Sci Rep 2018; 8:9203. [PMID: 29907782 PMCID: PMC6003933 DOI: 10.1038/s41598-018-26062-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 05/02/2018] [Indexed: 11/15/2022] Open
Abstract
The social brain hypothesis (SBH) posits that the demands imposed on individuals by living in cohesive social groups exert a selection pressure favouring the evolution of large brains and complex cognitive abilities. Using volumetry and the isotropic fractionator to determine the size of and numbers of neurons in specific brain regions, here we test this hypothesis in African mole-rats (Bathyergidae). These subterranean rodents exhibit a broad spectrum of social complexity, ranging from strictly solitary through to eusocial cooperative breeders, but feature similar ecologies and life history traits. We found no positive association between sociality and neuroanatomical correlates of information-processing capacity. Solitary species are larger, tend to have greater absolute brain size and have more neurons in the forebrain than social species. The neocortex ratio and neuronal counts correlate negatively with social group size. These results are clearly inconsistent with the SBH and show that the challenges coupled with sociality in this group of rodents do not require brain enlargement or fundamental reorganization. These findings suggest that group living or pair bonding per se does not select strongly for brain enlargement unless coupled with Machiavellian interactions affecting individual fitness.
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70
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Inference of ecological and social drivers of human brain-size evolution. Nature 2018; 557:554-557. [PMID: 29795254 DOI: 10.1038/s41586-018-0127-x] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 03/26/2018] [Indexed: 11/08/2022]
Abstract
The human brain is unusually large. It has tripled in size from Australopithecines to modern humans 1 and has become almost six times larger than expected for a placental mammal of human size 2 . Brains incur high metabolic costs 3 and accordingly a long-standing question is why the large human brain has evolved 4 . The leading hypotheses propose benefits of improved cognition for overcoming ecological5-7, social8-10 or cultural11-14 challenges. However, these hypotheses are typically assessed using correlative analyses, and establishing causes for brain-size evolution remains difficult15,16. Here we introduce a metabolic approach that enables causal assessment of social hypotheses for brain-size evolution. Our approach yields quantitative predictions for brain and body size from formalized social hypotheses given empirical estimates of the metabolic costs of the brain. Our model predicts the evolution of adult Homo sapiens-sized brains and bodies when individuals face a combination of 60% ecological, 30% cooperative and 10% between-group competitive challenges, and suggests that between-individual competition has been unimportant for driving human brain-size evolution. Moreover, our model indicates that brain expansion in Homo was driven by ecological rather than social challenges, and was perhaps strongly promoted by culture. Our metabolic approach thus enables causal assessments that refine, refute and unify hypotheses of brain-size evolution.
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Bogin B, Varea C, Hermanussen M, Scheffler C. Human life course biology: A centennial perspective of scholarship on the human pattern of physical growth and its place in human biocultural evolution. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 165:834-854. [DOI: 10.1002/ajpa.23357] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Barry Bogin
- School of Sport, Exercise & Health Sciences; Loughborough University, LE11 3TU; UK
| | - Carlos Varea
- Department of Biology, Physical Anthropology Group; Universidad Autónoma de Madrid; Madrid Spain
| | | | - Christiane Scheffler
- Institute of Biochemistry and Biology; University of Potsdam; Potsdam 14469 Germany
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Young JW, Shapiro LJ. Developments in development: What have we learned from primate locomotor ontogeny? AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 165 Suppl 65:37-71. [DOI: 10.1002/ajpa.23388] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Jesse W. Young
- Department of Anatomy and NeurobiologyNortheast Ohio Medical University (NEOMED)Rootstown Ohio, 44272
| | - Liza J. Shapiro
- Department of AnthropologyUniversity of TexasAustin Texas, 78712
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73
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Modeling Developmental Class Provides Insights into Individual Contributions to Infant Survival in Callitrichids. INT J PRIMATOL 2017. [DOI: 10.1007/s10764-017-9995-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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74
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Genoud M, Isler K, Martin RD. Comparative analyses of basal rate of metabolism in mammals: data selection does matter. Biol Rev Camb Philos Soc 2017; 93:404-438. [PMID: 28752629 DOI: 10.1111/brv.12350] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 05/29/2017] [Accepted: 06/05/2017] [Indexed: 12/21/2022]
Abstract
Basal rate of metabolism (BMR) is a physiological parameter that should be measured under strictly defined experimental conditions. In comparative analyses among mammals BMR is widely used as an index of the intensity of the metabolic machinery or as a proxy for energy expenditure. Many databases with BMR values for mammals are available, but the criteria used to select metabolic data as BMR estimates have often varied and the potential effect of this variability has rarely been questioned. We provide a new, expanded BMR database reflecting compliance with standard criteria (resting, postabsorptive state; thermal neutrality; adult, non-reproductive status for females) and examine potential effects of differential selectivity on the results of comparative analyses. The database includes 1739 different entries for 817 species of mammals, compiled from the original sources. It provides information permitting assessment of the validity of each estimate and presents the value closest to a proper BMR for each entry. Using different selection criteria, several alternative data sets were extracted and used in comparative analyses of (i) the scaling of BMR to body mass and (ii) the relationship between brain mass and BMR. It was expected that results would be especially dependent on selection criteria with small sample sizes and with relatively weak relationships. Phylogenetically informed regression (phylogenetic generalized least squares, PGLS) was applied to the alternative data sets for several different clades (Mammalia, Eutheria, Metatheria, or individual orders). For Mammalia, a 'subsampling procedure' was also applied, in which random subsamples of different sample sizes were taken from each original data set and successively analysed. In each case, two data sets with identical sample size and species, but comprising BMR data with different degrees of reliability, were compared. Selection criteria had minor effects on scaling equations computed for large clades (Mammalia, Eutheria, Metatheria), although less-reliable estimates of BMR were generally about 12-20% larger than more-reliable ones. Larger effects were found with more-limited clades, such as sciuromorph rodents. For the relationship between BMR and brain mass the results of comparative analyses were found to depend strongly on the data set used, especially with more-limited, order-level clades. In fact, with small sample sizes (e.g. <100) results often appeared erratic. Subsampling revealed that sample size has a non-linear effect on the probability of a zero slope for a given relationship. Depending on the species included, results could differ dramatically, especially with small sample sizes. Overall, our findings indicate a need for due diligence when selecting BMR estimates and caution regarding results (even if seemingly significant) with small sample sizes.
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Affiliation(s)
- Michel Genoud
- Department of Ecology and Evolution, University of Lausanne, CH-1015, Lausanne, Switzerland.,Division of Conservation Biology, Institute of Ecology and Evolution, Department of Biology, University of Bern, CH-3012, Bern, Switzerland
| | - Karin Isler
- Department of Anthropology, University of Zürich-Irchel, CH-8057, Zürich, Switzerland
| | - Robert D Martin
- Integrative Research Center, The Field Museum, Chicago, IL, 60605-2496, U.S.A.,Institute of Evolutionary Medicine, University of Zürich-Irchel, CH-8057, Zürich, Switzerland
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75
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Heldstab SA, van Schaik CP, Isler K. Getting fat or getting help? How female mammals cope with energetic constraints on reproduction. Front Zool 2017; 14:29. [PMID: 28616058 PMCID: PMC5468974 DOI: 10.1186/s12983-017-0214-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 05/31/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fat deposits enable a female mammal to bear the energy costs of offspring production and thus greatly influence her reproductive success. However, increasing locomotor costs and reduced agility counterbalance the fitness benefits of storing body fat. In species where costs of reproduction are distributed over other individuals such as fathers or non-breeding group members, reproductive females might therefore benefit from storing less energy in the form of body fat. RESULTS Using a phylogenetic comparative approach on a sample of 87 mammalian species, and controlling for possible confounding variables, we found that reproductive females of species with allomaternal care exhibit reduced annual variation in body mass (estimated as CV body mass), which is a good proxy for the tendency to store body fat. Differential analyses of care behaviours such as allonursing or provisioning corroborated an energetic interpretation of this finding. The presumably most energy-intensive form of allomaternal care, provisioning of the young, had the strongest effect on CV body mass. In contrast, allonursing, which involves no additional influx of energy but distributes maternal help across different mothers, was not correlated with CV body mass. CONCLUSIONS Our results suggest that reproducing females in species with allomaternal care can afford to reduce reliance on fat reserves because of the helpers' energetic contribution towards offspring rearing.
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Affiliation(s)
- Sandra A. Heldstab
- Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Carel P. van Schaik
- Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Karin Isler
- Department of Anthropology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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76
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Male alliance behaviour and mating access varies with habitat in a dolphin social network. Sci Rep 2017; 7:46354. [PMID: 28406176 PMCID: PMC5390316 DOI: 10.1038/srep46354] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 03/20/2017] [Indexed: 01/14/2023] Open
Abstract
Within-species variation in social structure has attracted interest recently because of the potential to explore phenotypic plasticity and, specifically, how demographic and ecological variation influence social structure. Populations of bottlenose dolphins (Tursiops spp.) vary in male alliance formation, from no alliances to simple pairs to, in Shark Bay, Western Australia, the most complex nested alliances known outside of humans. Examination of ecological contributions to this variation is complicated by differences among populations in other potentially explanatory traits, such as phylogenetic distance, as well as female reproductive schedules, sexual size dimorphism, and body size. Here, we report our discovery of systematic spatial variation in alliance structure, seasonal movements and access to mates within a single continuous social network in the Shark Bay population. Participation in male trios (versus pairs), the sizes of seasonal range shifts and consortship rates all decrease from north to south along the 50 km length of the study area. The southern habitat, characterised by shallow banks and channels, may be marginal relative to the open northern habitat. The discovery of variation in alliance behaviour along a spatial axis within a single population is unprecedented and demonstrates that alliance complexity has an ecological component.
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77
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Clark G, Henneberg M. Ardipithecus ramidus and the evolution of language and singing: An early origin for hominin vocal capability. HOMO-JOURNAL OF COMPARATIVE HUMAN BIOLOGY 2017; 68:101-121. [PMID: 28363458 DOI: 10.1016/j.jchb.2017.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 03/02/2017] [Indexed: 01/28/2023]
Abstract
In this paper we analyse the possibility that the early hominin Ardipithecus ramidus had vocal capabilities far exceeding those of any extant non-human primate. We argue that erect posture combined with changes in craniofacial morphology, such as reduced facial and jaw length, not only provide evidence for increased levels of pro-sociality, but also increased vocal ability. Reduced length of the face and jaw, combined with a flexed cranial base, suggests the larynx in this species was situated deeper in the neck than in chimpanzees, a trait which may have facilitated increased vocal ability. We also provide evidence that Ar. ramidus, by virtue of its erect posture, possessed a degree of cervical lordosis significantly greater than chimpanzees. This is indicative of increased mobility of the larynx within the neck and hence increased capacity to modulate vocalisations. In the paleoanthropological literature, these changes in early hominin skull morphology have to date been analysed in terms of a shift in mating and social behaviour, with little consideration given to vocally mediated sociality. Similarly, in the literature on language evolution there is a distinct lacuna regarding links between craniofacial correlates of social and mating systems and vocal ability. These are surprising oversights given that pro-sociality and vocal capability require identical alterations to the common ancestral skull and skeletal configuration. We therefore propose a model which integrates data on whole organism morphogenesis with evidence for a potential early emergence of hominin socio-vocal adaptations. Consequently, we suggest vocal capability may have evolved much earlier than has been traditionally proposed. Instead of emerging in the Homo genus, we suggest the palaeoecological context of late Miocene and early Pliocene forests and woodlands facilitated the evolution of hominin socio-vocal capability. We also propose that paedomorphic morphogenesis of the skull via the process of self-domestication enabled increased levels of pro-social behaviour, as well as increased capacity for socially synchronous vocalisation to evolve at the base of the hominin clade.
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Affiliation(s)
- Gary Clark
- Biological Anthropology and Comparative Anatomy Unit, Adelaide Medical School, The University of Adelaide, Adelaide 5005, Australia.
| | - Maciej Henneberg
- Biological Anthropology and Comparative Anatomy Unit, Adelaide Medical School, The University of Adelaide, Adelaide 5005, Australia.
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78
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Erb WM, Porter LM. Mother's little helpers: What we know (and don't know) about cooperative infant care in callitrichines. Evol Anthropol 2017; 26:25-37. [DOI: 10.1002/evan.21516] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Wendy M. Erb
- Department of Anthropology; Rutgers University; New Brunswick New Jersey 08901 USA
- The Center for Human Evolutionary Studies, Rutgers University; New Brunswick New Jersey 08901
| | - Leila M. Porter
- Department of Anthropology; Northern Illinois University; Dekalb Illinois 08901
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79
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Kenkel WM, Perkeybile AM, Carter CS. The neurobiological causes and effects of alloparenting. Dev Neurobiol 2017; 77:214-232. [PMID: 27804277 PMCID: PMC5768312 DOI: 10.1002/dneu.22465] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 08/26/2016] [Accepted: 10/15/2016] [Indexed: 12/21/2022]
Abstract
Alloparenting, defined as care provided by individuals other than parents, is a universal behavior among humans that has shaped our evolutionary history and remains important in contemporary society. Dysfunctions in alloparenting can have serious and sometimes fatal consequences for vulnerable infants and children. In spite of the importance of alloparenting, they still have much to learn regarding the underlying neurobiological systems governing its expression. Here, they review how a lack of alloparental behavior among traditional laboratory species has led to a blind spot in our understanding of this critical facet of human social behavior and the relevant neurobiology. Based on what is known, they draw from model systems ranging from voles to meerkats to primates to describe a conserved set of neuroendocrine mechanisms supporting the expression of alloparental care. In this review we describe the neurobiological and behavioral prerequisites, ontogeny, and consequences of alloparental care. Lastly, they identified several outstanding topics in the area of alloparental care that deserve further research efforts to better advance human health and wellbeing. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 214-232, 2017.
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Affiliation(s)
| | | | - C Sue Carter
- Kinsey Institute, Indiana University, Bloomington, Indiana
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80
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Scheiber IBR, Weiß BM, Kingma SA, Komdeur J. The importance of the altricial - precocial spectrum for social complexity in mammals and birds - a review. Front Zool 2017; 14:3. [PMID: 28115975 PMCID: PMC5242088 DOI: 10.1186/s12983-016-0185-6] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 12/08/2016] [Indexed: 12/31/2022] Open
Abstract
Various types of long-term stable relationships that individuals uphold, including cooperation and competition between group members, define social complexity in vertebrates. Numerous life history, physiological and cognitive traits have been shown to affect, or to be affected by, such social relationships. As such, differences in developmental modes, i.e. the ‘altricial-precocial’ spectrum, may play an important role in understanding the interspecific variation in occurrence of social interactions, but to what extent this is the case is unclear because the role of the developmental mode has not been studied directly in across-species studies of sociality. In other words, although there are studies on the effects of developmental mode on brain size, on the effects of brain size on cognition, and on the effects of cognition on social complexity, there are no studies directly investigating the link between developmental mode and social complexity. This is surprising because developmental differences play a significant role in the evolution of, for example, brain size, which is in turn considered an essential building block with respect to social complexity. Here, we compiled an overview of studies on various aspects of the complexity of social systems in altricial and precocial mammals and birds. Although systematic studies are scarce and do not allow for a quantitative comparison, we show that several forms of social relationships and cognitive abilities occur in species along the entire developmental spectrum. Based on the existing evidence it seems that differences in developmental modes play a minor role in whether or not individuals or species are able to meet the cognitive capabilities and requirements for maintaining complex social relationships. Given the scarcity of comparative studies and potential subtle differences, however, we suggest that future studies should consider developmental differences to determine whether our finding is general or whether some of the vast variation in social complexity across species can be explained by developmental mode. This would allow a more detailed assessment of the relative importance of developmental mode in the evolution of vertebrate social systems.
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Affiliation(s)
- Isabella B R Scheiber
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Brigitte M Weiß
- Behavioural Ecology Research Group, University of Leipzig, Faculty of Bioscience, Pharmacy and Psychology, Institute of Biology, Talstraße 33, 04103 Leipzig, Germany.,Department of Primatology, Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, 04103 Leipzig, Germany
| | - Sjouke A Kingma
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
| | - Jan Komdeur
- The University of Groningen, Behavioural and Physiological Ecology, Groningen Institute for Evolutionary Life Sciences (GELIFES), Nijenborgh 7, 9747 AG Groningen, The Netherlands
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81
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McKerracher LJ, Collard M, Altman RM, Sellen D, Nepomnaschy PA. Energy-related influences on variation in breastfeeding duration among indigenous Maya women from Guatemala. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2016; 162:616-626. [DOI: 10.1002/ajpa.23125] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 10/10/2016] [Accepted: 10/15/2016] [Indexed: 01/28/2023]
Affiliation(s)
- Luseadra J. McKerracher
- Human Evolutionary Studies Program; Simon Fraser University; Burnaby, British Columbia Canada V5A 1S6
- Department of Archaeology; Simon Fraser University; Burnaby, British Columbia Canada V5A 1S6
- Centre for Biocultural History; Aarhus University; Aarhus 8000 Denmark
| | - Mark Collard
- Human Evolutionary Studies Program; Simon Fraser University; Burnaby, British Columbia Canada V5A 1S6
- Department of Archaeology; Simon Fraser University; Burnaby, British Columbia Canada V5A 1S6
- Department of Archaeology; University of Aberdeen; Aberdeen AB24 3FX United Kingdom
| | - Rachel M. Altman
- Department of Statistics and Actuarial Science; Simon Fraser University; Burnaby, British Columbia Canada V5A 1S6
| | - Daniel Sellen
- Dalla Lana Institute for Public Health and Department of Anthropology; University of Toronto; Toronto Ontario Canada M5S 2S2
| | - Pablo A. Nepomnaschy
- Human Evolutionary Studies Program; Simon Fraser University; Burnaby, British Columbia Canada V5A 1S6
- Faculty of Health Sciences; Simon Fraser University; Burnaby, British Columbia Canada V5A 1S6
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82
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Abstract
Humans stand out among other primates by an unusual combination of a very large brain and high fertility. Pontzer et al. (2016a) present new data on daily energy expenditure in great apes and show that the metabolic rate increased during human evolution.
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Affiliation(s)
- Karin Isler
- Anthropological Institute and Museum, Division of Biology, University of Zurich, CH-8057 Zurich, Switzerland.
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83
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West HER, Capellini I. Male care and life history traits in mammals. Nat Commun 2016; 7:11854. [PMID: 27299954 PMCID: PMC4911630 DOI: 10.1038/ncomms11854] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 05/05/2016] [Indexed: 01/06/2023] Open
Abstract
Male care has energetic and opportunity costs, and is more likely to evolve when males gain greater certainty of paternity or when future mating opportunities are scarce. However, little is known about the substantial benefits that males may provide to females and offspring. Using phylogenetic comparative methods and a sample of over 500 mammalian species, we show that mammals in which males carry the offspring have shorter lactation periods, which leads to more frequent breeding events. Provisioning the female is associated with larger litters and shorter lactation. Offspring of species with male care have similar weaning mass to those without despite being supported by a shorter lactation period, implying that they grow faster. We propose that males provide an energetic contribution during the most expensive time of female reproduction, lactation, and that different male care behaviours increase female fecundity, which in turn helps males offset the costs of caring. Males help care for offspring in about 10% of mammal species. Here, West and Capellini perform phylogenetic comparative analyses on a sample of 529 mammal species and find that male care is associated with shorter lactation periods by females, larger litters of offspring, and more frequent breeding events.
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Affiliation(s)
- Hannah E R West
- School of Biological, Biomedical and Environmental Sciences University of Hull Cottingham Road, Hull HU6 7RX, UK
| | - Isabella Capellini
- School of Biological, Biomedical and Environmental Sciences University of Hull Cottingham Road, Hull HU6 7RX, UK
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84
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Thornton A, McAuliffe K, Dall SRX, Fernandez-Duque E, Garber PA, Young AJ. Fundamental problems with the cooperative breeding hypothesis. A reply to Burkart & van Schaik. J Zool (1987) 2016; 299:84-88. [PMID: 27570375 PMCID: PMC4982024 DOI: 10.1111/jzo.12351] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cooperative breeding hypothesis (CBH) states that cooperative breeding, a social system in which group members help to rear offspring that are not their own, has important socio‐cognitive consequences. Thornton & McAuliffe (2015; henceforth T&M) critiqued this idea on both conceptual and empirical grounds, arguing that there is no reason to predict that cooperative breeding should favour the evolution of enhanced social cognition or larger brains, nor any clear evidence that it does. In response to this critique, Burkart & van Schaik (2016 henceforth B&vS) attempt to clarify the causal logic of the CBH, revisit the data and raise the possibility that the hypothesis may only apply to primates. They concede that cooperative breeding is unlikely to generate selection pressures for enhanced socio‐cognitive abilities, but argue instead that the CBH operates purely through cooperative breeding reducing social or energetic constraints. Here, we argue that this revised hypothesis is also untenable because: (1) it cannot explain why resources so released would be allocated to cognitive traits per se rather than any other fitness‐related traits, (2) key assumptions are inconsistent with available evidence and (3) ambiguity regarding the predictions leaves it unclear what evidence would be required to falsify it. Ultimately, the absence of any compelling evidence that cooperative breeding is associated with elevated cognitive ability or large brains (indeed data suggest the opposite is true in non‐human primates) also casts doubt on the capacity of the CBH to explain variation in cognitive traits.
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Affiliation(s)
- A Thornton
- Centre for Ecology and Conservation University of Exeter Penryn UK
| | - K McAuliffe
- Department of Psychology Yale University New Haven CT USA; Department of Psychology Boston College Chestnut Hill MA USA
| | - S R X Dall
- Centre for Ecology and Conservation University of Exeter Penryn UK
| | | | - P A Garber
- Department of Anthropology University of Illinois Urbana IL USA
| | - A J Young
- Centre for Ecology and Conservation University of Exeter Penryn UK
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85
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Bader O. Attending to emotions is sharing of emotions - A multidisciplinary perspective to social attention and emotional sharing. Comment on Zahavi and Rochat (2015). Conscious Cogn 2016; 42:382-395. [PMID: 27152930 DOI: 10.1016/j.concog.2016.04.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 03/30/2016] [Accepted: 04/25/2016] [Indexed: 02/02/2023]
Abstract
Attending to bodily expression of emotions plays an important role in the human social world. It provides subjects with valuable information, constructs opportunities to act, and importantly, as Daniel Stern pointed out, it is involved in the constitution of the direct experience of others. Whether mutual or one-sided, these direct experiences, in which the subject can share the perspectives and attitudes of other subjects, always comprise one person's bodily expression of emotions that is available to another person. In this article I suggest that attending to other subjects' expressed emotions involves a special (social) mode of attention and emotional sharing. This suggestion challenges Dan Zahavi's view that confines the sharing of emotions solely to reciprocal experiences.
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Affiliation(s)
- Oren Bader
- The Cohn Institute for the History and Philosophy of Science an Ideas, School of Philosophy, The Lester and Sally Entin Faculty of Humanities, Tel Aviv University, Tel-Aviv 69978, Israel.
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86
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Grabowski M, Voje KL, Hansen TF. Evolutionary modeling and correcting for observation error support a 3/5 brain-body allometry for primates. J Hum Evol 2016; 94:106-16. [DOI: 10.1016/j.jhevol.2016.03.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 02/29/2016] [Accepted: 03/01/2016] [Indexed: 10/21/2022]
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87
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Schuppli C, Graber SM, Isler K, van Schaik CP. Life history, cognition and the evolution of complex foraging niches. J Hum Evol 2016; 92:91-100. [PMID: 26989019 DOI: 10.1016/j.jhevol.2015.11.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/11/2015] [Accepted: 11/12/2015] [Indexed: 11/29/2022]
Abstract
Animal species that live in complex foraging niches have, in general, improved access to energy-rich and seasonally stable food sources. Because human food procurement is uniquely complex, we ask here which conditions may have allowed species to evolve into such complex foraging niches, and also how niche complexity is related to relative brain size. To do so, we divided niche complexity into a knowledge-learning and a motor-learning dimension. Using a sample of 78 primate and 65 carnivoran species, we found that two life-history features are consistently correlated with complex niches: slow, conservative development or provisioning of offspring over extended periods of time. Both act to buffer low energy yields during periods of learning, and may thus act as limiting factors for the evolution of complex niches. Our results further showed that the knowledge and motor dimensions of niche complexity were correlated with pace of development in primates only, and with the length of provisioning in only carnivorans. Accordingly, in primates, but not carnivorans, living in a complex foraging niche requires enhanced cognitive abilities, i.e., a large brain. The patterns in these two groups of mammals show that selection favors evolution into complex niches (in either the knowledge or motor dimension) in species that either develop more slowly or provision their young for an extended period of time. These findings help to explain how humans constructed by far the most complex niche: our ancestors managed to combine slow development (as in other primates) with systematic provisioning of immatures and even adults (as in carnivorans). This study also provides strong support for the importance of ecological factors in brain size evolution.
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Affiliation(s)
- Caroline Schuppli
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
| | - Sereina M Graber
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
| | - Karin Isler
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
| | - Carel P van Schaik
- Anthropological Institute and Museum, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
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88
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Abelson ES. Brain size is correlated with endangerment status in mammals. Proc Biol Sci 2016; 283:20152772. [PMID: 26888034 PMCID: PMC4810832 DOI: 10.1098/rspb.2015.2772] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 01/26/2016] [Indexed: 11/12/2022] Open
Abstract
Increases in relative encephalization (RE), brain size after controlling for body size, comes at a great metabolic cost and is correlated with a host of cognitive traits, from the ability to count objects to higher rates of innovation. Despite many studies examining the implications and trade-offs accompanying increased RE, the relationship between mammalian extinction risk and RE is unknown. I examine whether mammals with larger levels of RE are more or less likely to be at risk of endangerment than less-encephalized species. I find that extant species with large levels of encephalization are at greater risk of endangerment, with this effect being strongest in species with small body sizes. These results suggest that RE could be a valuable asset in estimating extinction vulnerability. Additionally, these findings suggest that the cost-benefit trade-off of RE is different in large-bodied species when compared with small-bodied species.
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Affiliation(s)
- Eric S Abelson
- Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA
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89
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Affiliation(s)
- J. M. Burkart
- Anthropological Institute and Museum; University of Zurich; Zurich Switzerland
| | - C. P. van Schaik
- Anthropological Institute and Museum; University of Zurich; Zurich Switzerland
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90
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Hrdy SB. Variable postpartum responsiveness among humans and other primates with "cooperative breeding": A comparative and evolutionary perspective. Horm Behav 2016; 77:272-83. [PMID: 26518662 DOI: 10.1016/j.yhbeh.2015.10.016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 10/21/2015] [Accepted: 10/26/2015] [Indexed: 11/26/2022]
Abstract
This article is part of a Special Issue "Parental Care".Until recently, evolutionists reconstructing mother-infant bonding among human ancestors relied on nonhuman primate models characterized by exclusively maternal care, overlooking the highly variable responsiveness exhibited by mothers in species with obligate reliance on allomaternal care and provisioning. It is now increasingly recognized that apes as large-brained, slow maturing, and nutritionally dependent for so long as early humans were, could not have evolved unless "alloparents" (group members other than genetic parents), in addition to parents, had helped mothers to care for and provision offspring, a rearing system known as "cooperative breeding." Here I review situation-dependent maternal responses ranging from highly possessive to permissive, temporarily distancing, rejecting, or infanticidal, documented for a small subset of cooperatively breeding primates. As in many mammals, primate maternal responsiveness is influenced by physical condition, endocrinological priming, prior experience and local environments (especially related to security). But mothers among primates who evolved as cooperative breeders also appear unusually sensitive to cues of social support. In addition to more "sapient" or rational decision-making, humankind's deep history of cooperative breeding must be considered when trying to understand the extremely variable responsiveness of human mothers.
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Affiliation(s)
- Sarah B Hrdy
- Citrona Farms, 21440 County Road 87, Winters, CA 95694, USA.
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91
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Veitschegger K, Sánchez-Villagra MR. Tooth Eruption Sequences in Cervids and the Effect of Morphology, Life History, and Phylogeny. J MAMM EVOL 2015. [DOI: 10.1007/s10914-015-9315-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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92
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Fletcher GJO, Simpson JA, Campbell L, Overall NC. Pair-bonding, romantic love, and evolution: the curious case of Homo sapiens. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2015; 10:20-36. [PMID: 25910380 DOI: 10.1177/1745691614561683] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
This article evaluates a thesis containing three interconnected propositions. First, romantic love is a "commitment device" for motivating pair-bonding in humans. Second, pair-bonding facilitated the idiosyncratic life history of hominins, helping to provide the massive investment required to rear children. Third, managing long-term pair bonds (along with family relationships) facilitated the evolution of social intelligence and cooperative skills. We evaluate this thesis by integrating evidence from a broad range of scientific disciplines. First, consistent with the claim that romantic love is an evolved commitment device, our review suggests that it is universal; suppresses mate-search mechanisms; has specific behavioral, hormonal, and neuropsychological signatures; and is linked to better health and survival. Second, we consider challenges to this thesis posed by the existence of arranged marriage, polygyny, divorce, and infidelity. Third, we show how the intimate relationship mind seems to be built to regulate and monitor relationships. Fourth, we review comparative evidence concerning links among mating systems, reproductive biology, and brain size. Finally, we discuss evidence regarding the evolutionary timing of shifts to pair-bonding in hominins. We conclude there is interdisciplinary support for the claim that romantic love and pair-bonding, along with alloparenting, played critical roles in the evolution of Homo sapiens.
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93
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Szekely P, Korem Y, Moran U, Mayo A, Alon U. The Mass-Longevity Triangle: Pareto Optimality and the Geometry of Life-History Trait Space. PLoS Comput Biol 2015; 11:e1004524. [PMID: 26465336 PMCID: PMC4605829 DOI: 10.1371/journal.pcbi.1004524] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Accepted: 08/26/2015] [Indexed: 12/14/2022] Open
Abstract
When organisms need to perform multiple tasks they face a fundamental tradeoff: no phenotype can be optimal at all tasks. This situation was recently analyzed using Pareto optimality, showing that tradeoffs between tasks lead to phenotypes distributed on low dimensional polygons in trait space. The vertices of these polygons are archetypes--phenotypes optimal at a single task. This theory was applied to examples from animal morphology and gene expression. Here we ask whether Pareto optimality theory can apply to life history traits, which include longevity, fecundity and mass. To comprehensively explore the geometry of life history trait space, we analyze a dataset of life history traits of 2105 endothermic species. We find that, to a first approximation, life history traits fall on a triangle in log-mass log-longevity space. The vertices of the triangle suggest three archetypal strategies, exemplified by bats, shrews and whales, with specialists near the vertices and generalists in the middle of the triangle. To a second approximation, the data lies in a tetrahedron, whose extra vertex above the mass-longevity triangle suggests a fourth strategy related to carnivory. Each animal species can thus be placed in a coordinate system according to its distance from the archetypes, which may be useful for genome-scale comparative studies of mammalian aging and other biological aspects. We further demonstrate that Pareto optimality can explain a range of previous studies which found animal and plant phenotypes which lie in triangles in trait space. This study demonstrates the applicability of multi-objective optimization principles to understand life history traits and to infer archetypal strategies that suggest why some mammalian species live much longer than others of similar mass.
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Affiliation(s)
- Pablo Szekely
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Yael Korem
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Uri Moran
- Department of Plant Science, The Weizmann Institute of Science, Rehovot, Israel
| | - Avi Mayo
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
| | - Uri Alon
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel
- * E-mail:
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94
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The life history of Ardipithecus ramidus: a heterochronic model of sexual and social maturation. ANTHROPOLOGICAL REVIEW 2015. [DOI: 10.1515/anre-2015-0009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Abstract
In this paper we analyse the ontogeny of craniofacial growth in Ardipithecus ramidus in the context of its possible social and environmental determinants. We sought to test the hypothesis that this form of early hominin evolved a specific adult craniofacial morphology via heterochronic dissociation of growth trajectories. We suggest the lack of sexual dimorphism in craniofacial morphology provides evidence for a suite of adult behavioral adaptations, and consequently an ontogeny, unlike any other species of extant ape. The lack of sexually dimorphic craniofacial morphology suggests A. ramidus males adopted reproductive strategies that did not require male on male conflict. Male investment in the maternal metabolic budget and/or paternal investment in offspring may have been reproductive strategies adopted by males. Such strategies would account for the absence of innate morphological armoury in males. Consequently, A. ramidus would have most likely had sub-adult periods of socialisation unlike that of any extant ape. We also argue that A.ramidus and chimpanzee craniofacial morphology are apomorphic, each representing a derived condition relative to that of the common ancestor, with A. ramidus developing its orthognatic condition via paedomoporhosis, and chimpanzees evolving increased prognathism via peramorphosis. In contrast we suggest cranial volume and life history trajectories may be synapomorphic traits that both species inherited and retained form a putative common ancestral condition. Our analysis also provides support for the hypothesis that an intensification of maternal care was central to the process of hominization.
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95
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Weisbecker V, Blomberg S, Goldizen AW, Brown M, Fisher D. The evolution of relative brain size in marsupials is energetically constrained but not driven by behavioral complexity. BRAIN, BEHAVIOR AND EVOLUTION 2015; 85:125-35. [PMID: 25966967 DOI: 10.1159/000377666] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/02/2015] [Indexed: 11/19/2022]
Abstract
Evolutionary increases in mammalian brain size relative to body size are energetically costly but are also thought to confer selective advantages by permitting the evolution of cognitively complex behaviors. However, many suggested associations between brain size and specific behaviors - particularly related to social complexity - are possibly confounded by the reproductive diversity of placental mammals, whose brain size evolution is the most frequently studied. Based on a phylogenetic generalized least squares analysis of a data set on the reproductively homogenous clade of marsupials, we provide the first quantitative comparison of two hypotheses based on energetic constraints (maternal investment and seasonality) with two hypotheses that posit behavioral selection on relative brain size (social complexity and environmental interactions). We show that the two behavioral hypotheses have far less support than the constraint hypotheses. The only unambiguous associates of brain size are the constraint variables of litter size and seasonality. We also found no association between brain size and specific behavioral complexity categories within kangaroos, dasyurids, and possums. The largest-brained marsupials after phylogenetic correction are from low-seasonality New Guinea, supporting the notion that low seasonality represents greater nutrition safety for brain maintenance. Alternatively, low seasonality might improve the maternal support of offspring brain growth. The lack of behavioral brain size associates, found here and elsewhere, supports the general 'cognitive buffer hypothesis' as the best explanatory framework of mammalian brain size evolution. However, it is possible that brain size alone simply does not provide sufficient resolution on the question of how brain morphology and cognitive capacities coevolve.
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Affiliation(s)
- Vera Weisbecker
- School of Biological Sciences, University of Queensland, St. Lucia, Qld., Australia
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96
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Abstract
I present evidence that humans have evolved convergently to social insects with regard to a large suite of social, ecological, and reproductive phenotypes. Convergences between humans and social insects include: (1) groups with genetically and environmentally defined structures; (2) extensive divisions of labor; (3) specialization of a relatively restricted set of females for reproduction, with enhanced fertility; (4) extensive extramaternal care; (5) within-group food sharing; (6) generalized diets composed of high-nutrient-density food; (7) solicitous juveniles, but high rates of infanticide; (8) ecological dominance; (9) enhanced colonizing abilities; and (10) collective, cooperative decision-making. Most of these convergent phenotypic adaptations stem from reorganization of key life-history trade-offs due to behavioral, physiological, and life-historical specializations. Despite their extensive socioreproductive overlap with social insects, humans differ with regard to the central aspect of eusociality: reproductive division of labor. This difference may be underpinned by the high energetic costs of producing offspring with large brains.
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Affiliation(s)
- Bernard Crespi
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada, V5A 1S6,
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97
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Jin T, Wang D, Pan W, Yao M. Nonmaternal Infant Handling in Wild White-Headed Langurs (Trachypithecus leucocephalus). INT J PRIMATOL 2015. [DOI: 10.1007/s10764-015-9823-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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98
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Thornton A, McAuliffe K. Cognitive consequences of cooperative breeding? A critical appraisal. J Zool (1987) 2015. [DOI: 10.1111/jzo.12198] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- A. Thornton
- Centre for Ecology and Conservation; University of Exeter; Penryn UK
| | - K. McAuliffe
- Department of Psychology; Yale University; New Haven CT USA
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100
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Finlay BL, Syal S. The pain of altruism. Trends Cogn Sci 2014; 18:615-7. [DOI: 10.1016/j.tics.2014.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Revised: 08/11/2014] [Accepted: 08/12/2014] [Indexed: 10/24/2022]
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