Cultural Relatedness and Human Social Evolution

Mapping Intimacies ◽

10.1093/oso/9780198733058.003.0008 ◽

2017 ◽

Author(s):

Jonathan Birch

Keyword(s):

Reproductive Success ◽

Cultural Differences ◽

Cultural Evolution ◽

Social Evolution ◽

Genetic Relatedness ◽

Human Populations ◽

Free Riders ◽

Self Interest ◽

Human Social Evolution ◽

Early Human

Humans often set aside their own self-interest to help others and punish free riders, even when interacting with strangers. To explain the origin of these ‘broad-scope prosocial preferences’, we should consider the processes of cultural evolution that might have acted in early human populations. Two types of cultural selection can be distinguished: CS1, in which cultural differences between individuals cause differences in their reproductive success; and CS2, in which cultural differences between individuals cause differences in their ‘cultural fitness’. This chapter proposes, speculatively, that human social evolution involved a gradual decoupling of cultural fitness from reproductive success. A cultural version of Hamilton’s rule, in which the coefficient of genetic relatedness is replaced by a coefficient of cultural relatedness, provides a helpful organizing framework for thinking about the evolution of social behaviour by CS1, and leads to a ‘cultural relatedness hypothesis’ regarding the origins of human prosociality.

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New research frameworks in the study of chimpanzee and gorilla sociality and communication

10.32942/osf.io/d8j3r ◽

2019 ◽

Author(s):

Sam G. B. Roberts ◽

Anna Roberts

Keyword(s):

Social Evolution ◽

Social Complexity ◽

Brain Size ◽

Social Systems ◽

Strongly Correlated ◽

The Social ◽

Human Social Evolution ◽

Research Frameworks ◽

New Research ◽

Large Groups

Group size in primates is strongly correlated with brain size, but exactly what makes larger groups more ‘socially complex’ than smaller groups is still poorly understood. Chimpanzees (Pan troglodytes) and gorillas (Gorilla gorilla) are among our closest living relatives and are excellent model species to investigate patterns of sociality and social complexity in primates, and to inform models of human social evolution. The aim of this paper is to propose new research frameworks, particularly the use of social network analysis, to examine how social structure differs in small, medium and large groups of chimpanzees and gorillas, to explore what makes larger groups more socially complex than smaller groups. Given a fission-fusion system is likely to have characterised hominins, a comparison of the social complexity involved in fission-fusion and more stable social systems is likely to provide important new insights into human social evolution

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Dream-Sharing and Human Self-Domestication

10.31234/osf.io/7ytn5 ◽

2021 ◽

Author(s):

Mark Blagrove ◽

Julia Lockheart

Keyword(s):

Emotional Reactivity ◽

Social Evolution ◽

Cultural Practices ◽

Neural Mechanisms ◽

The Social ◽

Primary Driver ◽

Group Members ◽

Human Social Evolution ◽

Dream Sharing ◽

Experimental Findings

There are many theories of the function of dreams, such as memory consolidation, emotion processing, threat simulation and social simulation. In general, such theories hold that the function of dreams occurs within sleep; occurs for unrecalled dreams as well as for dream that are recalled on awakening; and that conscious recall of dreams is not necessary for their function to occur. In contrast, we propose that dreams have an effect of enhancing empathy and group bonding when dreams are shared and discussed with others. We propose also that this effect would have occurred in history and pre-history and, as it would have enhanced the cohesiveness and mutual understanding of group members, the fictional and engaging characteristics of dream content would have been selected for during human social evolution, interacting with cultural practices of dream-sharing. Such dream-sharing may have taken advantage of the long REM periods that occur for biological reasons near the end of the night. Dream-production and dream-sharing may have developed alongside story-telling, utilising common neural mechanisms. Dream-sharing hence would have contributed to Human Self-Domestication, held by many researchers to be the primary driver of the evolution of human prosociality, tolerance and reduced intragroup emotional reactivity. We note that within-sleep theories of dream function rely on correlational rather than experimental findings, and have as yet untested and speculative mechanisms, whereas post-sleep effects of dream-sharing are easily testable and have mechanisms congruent with the social processes proposed by the theory of Human Self-Domestication.

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Self-interest and social evolution

Order and Anarchy ◽

10.1017/cbo9780511617263.002 ◽

2009 ◽

pp. 46-91

Author(s):

Robert Layton

Keyword(s):

Social Evolution ◽

Self Interest

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Ecology of the Anthropocene signals hope for consciously managing the planetary ecosystem

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2024150118 ◽

2021 ◽

Vol 118 (28) ◽

pp. e2024150118

Author(s):

Clarence Lehman ◽

Shelby Loberg ◽

Michael Wilson ◽

Eville Gorham

Keyword(s):

Population Growth ◽

Cultural Evolution ◽

Human Population ◽

Human Populations ◽

Present Moment ◽

Minimal Set ◽

The Past ◽

Food Species ◽

Large Predators ◽

Population Numbers

Human populations have grown to such an extent that our species has become a dominant force on the planet, prompting geologists to begin applying the term Anthropocene to recognize the present moment. Many approaches seek to explain the past and future of human population growth, in the form of narratives and models. Some of the most influential models have parameters that cannot be precisely known but are estimated by expert opinion. Here we apply a unified model of ecology to provide a macroscale summary of the net effects of many microscale processes, using a minimal set of parameters that can be known. Our models match estimates of historic and prehistoric global human population numbers and provide predictions that correspond to some of the more complicated current models. In addition to fitting the data well they reveal that, amidst enormous complexity in our human and prehuman past, three key ecological discontinuities have occurred in turn: 1) becoming dominant competitors of large predators rather than their prey, 2) becoming mutualists with food species rather than acting as predators upon them, and 3) changing from a regime of uncontrolled population growth to one of controlled fertility instead. All three processes have been interlinked with cultural evolution and all three ushered in developments of the Anthropocene. Understanding the trajectories that have delivered us to this stage can help guide prudent paths into the future.

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Quantifying the prevalence of assortative mating in a human population

10.1101/848911 ◽

2019 ◽

Author(s):

Klaus Jaffe

Keyword(s):

Assortative Mating ◽

Genetic Relatedness ◽

Random Mating ◽

Human Populations ◽

Genetic Composition ◽

Genetic Studies ◽

Maintenance Of Sex ◽

Animal Populations ◽

The Uk ◽

First Time

AbstractFor the first time, empirical evidence allowed to construct the frequency distribution of a genetic relatedness index between the parents of about half a million individuals living in the UK. The results suggest that over 30% of the population is the product of parents mating assortatively. The rest is probably the offspring of parents matching the genetic composition of their partners randomly. High degrees of genetic relatedness between parents, i.e. extreme inbreeding, was rare. This result shows that assortative mating is likely to be highly prevalent in human populations. Thus, assuming only random mating among humans, as widely done in ecology and population genetic studies, is not an appropriate approximation to reality. The existence of assortative mating has to be accounted for. The results suggest the conclusion that both, assortative and random mating, are evolutionary stable strategies. This improved insight allows to better understand complex evolutionary phenomena, such as the emergence and maintenance of sex, the speed of adaptation, runaway adaptation, maintenance of cooperation, and many others in human and animal populations.

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Long-term mating positively predicts both reproductive fitness and parental investment

Journal of Biosocial Science ◽

10.1017/s0021932021000407 ◽

2021 ◽

pp. 1-12

Author(s):

Janko Međedović

Keyword(s):

Sexual Selection ◽

Reproductive Success ◽

Parental Investment ◽

Reproductive Fitness ◽

Human Populations ◽

Number Of Children ◽

Fitness Indicators ◽

Number Of Sexual Partners ◽

Sexual Selection Theory

Abstract Empirical data on the relations between mating and reproductive success are rare for humans, especially for industrial and post-industrial populations. Existing data show that mating (and especially long-term mating) can be beneficial for fitness, especially that of males. This finding is in line with the hypothesis of sexual selection operating in human populations. The present research expands on previous studies by: 1) analysing additional fitness indicators, including having children with different partners; 2) including parental investment in the analysis as another important marker of sexual selection; 3) analysing several mediators between mating, reproductive fitness and parental investment, i.e. age of first and last reproduction and desired number of children. The data were obtained in 2019 from a sample of parents living in Serbia (N=497). The findings showed that long-term mating (duration of longest partner relationship) was positively related to parental investment and number of offspring and grand-offspring. Furthermore, the link between long-term mating and reproductive success was completely mediated by the age of first reproduction and desired number of children. Short-term mating (number of sexual partners) was marginally positively related to the number of children participants had with different partners and negatively related to parental investment. No sex differences in the link between mating, fitness and parental investment were detected. In general, the signatures of sexual selection were weak in the present data, but those that were detected were in line with sexual selection theory. The present findings provide a deeper insight into the adaptive function of mating and also the mechanism of how mating is beneficial for fitness.

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The cognitive science of souls: Clarifications and extensions of the evolutionary model

Behavioral and Brain Sciences ◽

10.1017/s0140525x06499106 ◽

2006 ◽

Vol 29 (5) ◽

pp. 486-493 ◽

Cited By ~ 9

Author(s):

Jesse M. Bering

Keyword(s):

Cognitive Science ◽

Intelligent Design ◽

Social Evolution ◽

Evolutionary Model ◽

Research Programme ◽

Cognitive System ◽

Symbolic Meaning ◽

Human Social Evolution ◽

Insight Into

The commentaries are a promising sign that a research programme on the cognitive science of souls will continue to move toward empirical and theoretical rigor. Most of the commentators agree that beliefs in personal immortality, in the intelligent design of souls, and in the symbolic meaning of natural events can provide new insight into human social evolution. In this response I clarify and extend the evolutionary model, further emphasizing the adaptiveness of the cognitive system that underlies these beliefs.

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Social Bacteriophages

Microorganisms ◽

10.3390/microorganisms8040533 ◽

2020 ◽

Vol 8 (4) ◽

pp. 533

Author(s):

Pilar Domingo-Calap ◽

Lucas Mora-Quilis ◽

Rafael Sanjuán

Keyword(s):

Spatial Structure ◽

Social Evolution ◽

Genetic Relatedness ◽

Population Level ◽

Mechanisms Of Action ◽

Evolution Theory ◽

Superinfection Exclusion ◽

Key Population ◽

Viral Product ◽

Host Exploitation

Despite their simplicity, viruses can display social-like interactions such as cooperation, communication, and cheating. Focusing on bacteriophages, here we review features including viral product sharing, cooperative evasion of antiviral defenses, prudent host exploitation, superinfection exclusion, and inter-phage peptide-mediated signaling. We argue that, in order to achieve a better understanding of these processes, their mechanisms of action need to be considered in the context of social evolution theory, paying special attention to key population-level factors such as genetic relatedness and spatial structure.

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Grandma plays favourites: X-chromosome relatedness and sex-specific childhood mortality

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2009.1660 ◽

2009 ◽

Vol 277 (1681) ◽

pp. 567-573 ◽

Cited By ~ 52

Author(s):

Molly Fox ◽

Rebecca Sear ◽

Jan Beise ◽

Gillian Ragsdale ◽

Eckart Voland ◽

...

Keyword(s):

X Chromosome ◽

Genetic Relatedness ◽

Family Members ◽

Childhood Mortality ◽

Human Populations ◽

Kin Investment ◽

Grandmother Hypothesis ◽

New Perspective ◽

Post Menopausal ◽

Developmental Traits

Biologists use genetic relatedness between family members to explain the evolution of many behavioural and developmental traits in humans, including altruism, kin investment and longevity. Women's post-menopausal longevity in particular is linked to genetic relatedness between family members. According to the ‘grandmother hypothesis’, post-menopausal women can increase their genetic contribution to future generations by increasing the survivorship of their grandchildren. While some demographic studies have found evidence for this, others have found little support for it. Here, we re-model the predictions of the grandmother hypothesis by examining the genetic relatedness between grandmothers and grandchildren. We use this new model to re-evaluate the grandmother effect in seven previously studied human populations. Boys and girls differ in the per cent of genes they share with maternal versus paternal grandmothers because of differences in X-chromosome inheritance. Here, we demonstrate a relationship between X-chromosome inheritance and grandchild mortality in the presence of a grandmother. With this sex-specific and X-chromosome approach to interpreting mortality rates, we provide a new perspective on the prevailing theory for the evolution of human female longevity. This approach yields more consistent support for the grandmother hypothesis, and has implications for the study of human evolution.

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