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The notions of natural selection and drift also apply to humans and their biological and cultural evolution. The science of paleoanthropology explains human evolution through the study of intermediate fossil forms. In addition, geneticists have been able to retrace, through the study of mitochondrial DNA and Y-chromosome DNA, the origin and migrations of prehistoric humans. The understanding of human cultural evolution has greatly benefited from the application of evolutionary thinking.

Human social communication is impaired in the two primary disorders of the ‘social brain’, autism, and schizophrenia. This chapter describes a new hypothesis for the role of language in the evolution and development of autism and schizophrenia: that the cores of these two conditions are disordered social communication, with dysregulated social-linguistic development mediated in part by extremes of bias in maternal vs paternal imprinted gene expression, resulting in extreme mentalistic vs extreme mechanistic cognition. It evaluates this hypothesis via tests of the molecular evolution of genes underlying schizophrenia and language, analyses of how the human social brain has evolved, and evaluation of the roles of genomic conflicts in human development, enculturation, and communication via study of the genetic and epigenetic underpinnings of social-brain disorders. These convergent lines of evidence from evolutionary theory and neurogenomics support the hypothesis that psychosis represents the ‘illness that made us human’.

This chapter deals with one of the most long-debated question about how dogs became domesticated. Traditional understanding of this process was based on the finding of archaeologists that are, however, restricted to only a few geographic locations and time periods. The possibility of scientific inquiry about domestication has changed with the introduction of novel phylogenetic approaches based on molecular biological methods, which, however, are also not without problems. The chapter provides an introduction to constraints presented by both the archaeological and the phylogenetic investigations, and reviews the problems of tracing genetic evolution. Finally, a possible multi-step framework for dog domestication is presented.

This chapter assesses the number of grades that have appeared in the course of human evolution. It identifies three grades. The first is characterised by a species mean body mass of under 50 kg; a species mean stature of less than 150 cm; facultative bipedalism; relatively large teeth and jaws; a moderate size brain relative to body mass; and a relatively short period of maturation. The second grade is characterised by a species mean body mass of more than 50 kg; a species mean stature in excess of 150 cm; obligate bipedalism; relatively small teeth and jaws; a moderate size brain relative to body mass; and a relatively short period of maturation. The third grade is similar to the second in terms of body mass, stature, locomotor behaviour and masticatory system size; but exhibits a considerably higher level of encephalisation. It also exhibits delayed maturation.

Culture has fundamentally changed the nature of human evolution because it creates a novel evolutionary tradeoff. Social learning allows human populations to rapidly evolve accumulate cultural evolution of highly adaptive culturally transmitted behaviors. However, to get the benefits of social learning, humans have to be credulous, for the most part accepting the ways that they observe in their society as sensible and proper; such credulity opens up human minds to the spread of maladaptive beliefs. These costs can be reduced by tinkering with our evolved psychology, but they cannot be eliminated without losing the adaptive benefits of cumulative cultural evolution. The classic nature-nurture controversy neglects the processes of gene-culture coevolution. An evolutionary psychology lacking an account of this fundamental tradeoff cannot successfully explain human evolution.

Human nature is the product of a long history that has brought us, over the course of some 6–8 million years, from our common ancestor with the chimpanzee lineage to modern humans. The aim of this particular volume has been to bring together two powerful approaches that deal, respectively, with explanations of the evolution of human brains and understandings of cognition as a distributed system, in order to illuminate the changes that took place during the later stages of human evolution. It aims to compare inter-disciplinary perspectives on these key issues across a range of disciplines. A particular focus is provided by consideration of the role that material culture plays as a scaffold for distributed cognition, and how almost 3 million years of artefact and tool use and manufacture provide the data for tracing key changes in areas such as language, technology, kinship, music, and social networks.

The mastery of fire is a great human achievement which has helped shape our species. This chapter addresses the wider importance of fire, arguing that it is part of a fundamental motor of human evolution, deeply tied into our biology as well as economy and technology, and indeed a motor of the social brain. It seems likely that fire was involved in this nexus from a very early period, probably back to the time of increases in human brain size in the early Pleistocene, and indeed that it may have been a necessity for the subsequent physical evolutionary and social developments in Homo. Fire may be associated so strongly with imagery, imagination and symbolism in the modern world as a result of its primary role in effecting transformation of materials, and acting to link various strands of material culture.

This chapter reviews evidence for the evolution of primate asymmetries in brain morphology and in behaviour, including the fossil and archaeological record of human evolution. This evidence suggests that, while morphological asymmetries are conserved features of the human brain, human functional asymmetries are derived, at least in their degree and consistency. The discussion offers a partial explanation that takes account of allometric scaling in the evolution of brain size, neocortex size, and intra- and interhemispheric connectivity.

This chapter poses the question of the evolution of intellectual faculties. But a satisfactory explanation demands insight into the evolutionary origins of some of our most striking attributes—our intelligence, language, cooperation, teaching, and morality—yet most of these features are not just distinctive, they are unique to our species. That makes it harder to glean clues to the distant history of our minds through comparison with other species. At the heart of this challenge lies the undeniable fact that we humans are an amazingly successful species. Our range is unprecedented; we have colonized virtually every terrestrial habitat on Earth; exhibit behavioral diversity that is unparalleled in the animal kingdom; and resolved countless ecological, social, and technological challenges. When one considers that the life history, social life, sexual behavior, and foraging patterns of humans have also diverged sharply from those of other apes, there are grounds for claiming that human evolution exhibits unusual and striking features that go beyond our self-obsession and demand explanation.

Evolutionary approaches to religion and the social brain hypothesis are ripe for functional integration. One conceptual link for such integration lies in recognizing the artificially imposed distinction between religion and most other aspects of culture found in band-level societies. This chapter argues that throughout most of human evolution, religion has organized the patterns of belief and behaviour in which the social brain operates. Religious beliefs, myths, symbols and rituals are the means by which emotional bonding, enculturation and identification with an in-group occur. The chapter presents a developmental account of socio-religious enculturation in order to clarify the unique role religion plays in social cognition. It proposes that the particulars of religious systems are introduced and practised during childhood, sealed in adolescence, reinforced throughout reproductive adulthood and transmitted by post-reproductive adults.

This chapter explains why the process of human evolution is crucial to understanding the structures and functions of the modern human mind. Tracing hominid development up to the appearance of Homo sapiens, the chapter explores some of the selective pressures faced in our ancestral past, and the cognitive adaptations that gave rise to human intelligence. It shows how the ultimate success of Homo sapiens was the result of mental mechanisms (e.g., theory of mind, social intelligence, and language) that fitted humans to the “cognitive niche” — an adaptive space characterized by the gathering and strategic use of information — and that remain the hallmarks of human thought and behavior today.

This chapter argues the case that the speciation of modern Homo sapiens exemplifies the principle of punctuated equilibria, i.e. it is a saltational change. Evolutionary saltation is a rather ill-defined Victorian concept that may contrast in various ways with gradual (linear) evolution. The discussion looks at the human morphological and behavioural records in an attempt to discern pattern in human evolution, and particularly in the emergence of Homo sapiens. Homo sapiens is a variable species, although not notably more so than Homo neanderthalensis, which can itself be understood only in the context of its membership in a diverse clade of endemic European species. The record clearly indicates that both modern human morphology and modern human cognitive processes appeared rather suddenly, even saltationally, although not at the same time.

This chapter examines the evidence that our cultural activities have influenced our biological evolution, by drawing on a cocktail of theoretical and empirical findings. It begins by relating findings from theoretical studies, which show through mathematical modeling that gene–culture coevolution is, at least in principle, highly plausible. Then the anthropological evidence for gene–culture coevolution is surveyed. Here, compelling and well-researched case studies provide incontrovertible evidence that gene–culture coevolution is a biological fact. Finally, some genetic data are presented—specifically, studies that have identified human genes subject to recent natural selection, including genes expressed in the brain. Many such genes (strictly, “alleles,” or gene variants) have increased extremely rapidly in frequency over a few thousand years, and this unusually swift spread, known as a “selective sweep,” is taken as a sign of their having being favored by natural selection. The relevance of such studies stems from the fact that the geneticists who carried them out have concluded that the sweeps are almost certainly a response to human cultural activities. Collectively, these three bodies of evidence make a compelling case that culture is not just a product, but also a codirector, of human evolution.

The cognitive, psychological and sociological mechanisms underpinning complex social relationships among small groups are a part of our primate heritage. However, among human groups, relationships persist over much greater temporal and spatial scales, often in the physical absence of one or other of the individuals themselves. This chapter examines how such individual face-to-face social interactions were ‘scaled up’ during human evolution to the regional and global networks characteristic of modern societies. One recent suggestion has been that a radical change in human sociality occurred with the shift to sedentary and agricultural societies in the early Neolithic. The discussion presents the results of a focused study of the long-term development of regional social networks in the Near East, using the distribution of different forms of material culture as a proxy for the social relationships that underpinned processes of trade, exchange and the dissemination of material culture practices.

This chapter introduces the new understanding from recent climatic and archaeological research of how human societies gradually developed increasingly important associations with edible plants. For the past two million years, life on earth has been largely dominated by hypervariable climatic conditions, fluctuating between relatively mild, damp conditions and much colder, drier states. Humans evolved during this period as efficient and relatively mobile hunter-gatherers, and by about 20,000 BP they had spread across much of the world. Over the past 100,000 years, human cognitive skills gradually increased, which facilitated more efficient social interactions and enabled people to adapt better to their unpredictable and ever-changing environments. During the Upper Palaeolithic (c.50,000-11,500 BP), as some of the megafauna became extinct, many human groups relied increasingly on a mixture of small game and plants, gradually becoming skilled exploiters and manipulators of numerous useful plant resources including fruits and seeds.