The self-domestication hypothesis suggests that, like mammalian domesticates, humans have gone through a process of selection against aggression - a process that in the case of humans was ...self-induced. Here, we extend previous proposals and suggest that what underlies human social evolution is selection for socially mediated emotional control and plasticity. In the first part of the paper we highlight general features of human social evolution, which, we argue, is more similar to that of other social mammals than to that of mammalian domesticates and is therefore incompatible with the notion of human self-domestication. In the second part, we discuss the unique aspects of human evolution and propose that emotional control and social motivation in humans evolved during two major, partially overlapping stages. The first stage, which followed the emergence of mimetic communication, the beginnings of musical engagement, and mimesis-related cognition, required socially mediated emotional plasticity and was accompanied by new social emotions. The second stage followed the emergence of language, when individuals began to instruct the imagination of their interlocutors, and to rely even more extensively on emotional plasticity and culturally learned emotional control. This account further illustrates the significant differences between humans and domesticates, thus challenging the notion of human self-domestication.
The ambrosia beetle-fungus farming symbiosis is more heterogeneous than previously thought. There is not one but many ambrosia symbioses. Beetle-fungus specificity is clade dependent and ranges from ...strict to promiscuous. Each new origin has evolved a new mycangium. The most common relationship with host trees is colonization of freshly dead tissues, but there are also parasites of living trees, vectors of pathogenic fungi, and beetles living in rotten trees with a wood-decay symbiont. Most of these strategies are driven by fungal metabolism whereas beetle ecology is evolutionarily more flexible. The ambrosia lifestyle facilitated a radiation of social strategies, from fungus thieves to eusocial species to communities assembled by attraction to fungal scent. Although over 95% of the symbiotic pairs are economically harmless, there are also three types of pest damage: tree pathogen inoculation, mass accumulation on susceptible hosts, and structural damage. Beetles able to colonize live tree tissues are most likely to become invasive pests.
Microbes are typically surrounded by different strains and species with whom they compete for scarce nutrients and limited space. Given such challenging living conditions, microbes have evolved many ...phenotypes with which they can outcompete and displace their neighbours: secretions to harvest resources, loss of costly genes whose products can be obtained from others, stabbing and poisoning neighbouring cells, or colonising spaces while preventing others from doing so. These competitive phenotypes appear to be common, although evidence suggests that, over time, competition dies down locally, often leading to stable coexistence of genetically distinct lineages. Nevertheless, the selective forces acting on competition and the resulting evolutionary fates of the different players depend on ecological conditions in a way that is not yet well understood. Here, we highlight open questions and theoretical predictions of the long-term dynamics of competition that remain to be tested. Establishing a clearer understanding of microbial competition will allow us to better predict the behaviour of microbes, and to control and manipulate microbial communities for industrial, environmental, and medical purposes.
Many species of microbes cooperate by producing public goods from which they collectively benefit. However, these populations are under the risk of being taken over by cheating mutants that do not ...contribute to the pool of public goods. Here we present theoretical findings that address how the social evolution of microbes can be manipulated by external perturbations to inhibit or promote the fixation of cheaters. To control social evolution, we determine the effects of fluid-dynamical properties such as flow rate or domain geometry. We also study the social evolutionary consequences of introducing beneficial or harmful chemicals at steady state and in a time-dependent fashion. We show that by modulating the flow rate and by applying pulsed chemical signals, we can modulate the spatial structure and dynamics of the population in a way that can select for more or less cooperative microbial populations.
The hypothesis that eusociality originated once in Vespidae has shaped interpretation of social evolution for decades and has driven the supposition that preimaginal morphophysiological differences ...between castes were absent at the outset of eusociality. Many researchers also consider casteless nest-sharing an antecedent to eusociality. Together, these ideas endorse a stepwise progression of social evolution in wasps (solitary → casteless nest-sharing → eusociality with rudimentary behavioral castes → eusociality with preimaginal caste-biasing (PCB) → morphologically differentiated castes). Here, we infer the phylogeny of Vespidae using sequence data generated via anchored hybrid enrichment from 378 loci across 136 vespid species and perform ancestral state reconstructions to test whether rudimentary and monomorphic castes characterized the initial stages of eusocial evolution. Our results reject the single origin of eusociality hypothesis, contest the supposition that eusociality emerged from a casteless nest-sharing ancestor, and suggest that eusociality in Polistinae + Vespinae began with castes having morphological differences. An abrupt appearance of castes with ontogenetically established morphophysiological differences conflicts with the current conception of stepwise social evolution and suggests that the climb up the ladder of sociality does not occur through sequential mutation. Phenotypic plasticity and standing genetic variation could explain how cooperative brood care evolved in concert with nest-sharing and how morphologically dissimilar castes arose without a rudimentary intermediate. Furthermore, PCB at the outset of eusociality implicates a subsocial route to eusociality in Polistinae + Vespinae, emphasizing the role of mother-daughter interactions and subfertility (i.e. the cost component of kin selection) in the origin of workers.
InThe Hadza, Frank Marlowe provides a quantitative ethnography of one of the last remaining societies of hunter-gatherers in the world. The Hadza, who inhabit an area of East Africa near the ...Serengeti and Olduvai Gorge, have long drawn the attention of anthropologists and archaeologists for maintaining a foraging lifestyle in a region that is key to understanding human origins. Marlowe ably applies his years of research with the Hadza to cover the traditional topics in ethnography-subsistence, material culture, religion, and social structure. But the book's unique contribution is to introduce readers to the more contemporary field of behavioral ecology, which attempts to understand human behavior from an evolutionary perspective. To that end,The Hadzaalso articulates the necessary background for readers whose exposure to human evolutionary theory is minimal.
Interference with public good cooperation provides a promising novel antimicrobial strategy since social evolution theory predicts that resistant mutants will be counter-selected if they share the ...public benefits of their resistance with sensitive cells in the population. Although this hypothesis is supported by a limited number of pioneering studies, an extensive body of more fundamental work on social evolution describes a multitude of mechanisms and conditions that can stabilize public behaviour, thus potentially allowing resistant mutants to thrive. In this paper we theorize on how these different mechanisms can influence the evolution of resistance against public good inhibitors. Based hereon, we propose an innovative 5-step screening strategy to identify novel evolution-proof public good inhibitors, which involves a systematic evaluation of the exploitability of public goods under the most relevant experimental conditions, as well as a careful assessment of the most optimal way to interfere with their action. Overall, this opinion paper is aimed to contribute to long-term solutions to fight bacterial infections.
Social Indicators Research (SIR) year by year has consolidated its preeminent position in the debate concerning the study of all the aspects of
quality of life
. The need of a journal focused on the ...quantitative evaluation of social realities and phenomena dating back to the seventies, when a new branch of Social Science—called
Social Indicators Research
—came into the international scientific landscape. This paper aims at reviewing the whole collection of publications appeared on SIR from 1989 to 2018, providing a complete overview of the main factor that affected the journal in the last 30 years. The approach followed to analyse this extensive
corpus
of documents relies upon the theoretical framework of bibliometric studies.