Search Results

Reticulate evolution in the hominines

Michael L. Arnold

in Reticulate Evolution and Humans: Origins and Ecology

This chapter discusses evidence for reticulation evolution among the ancestors of the network that includes gorillas, chimpanzees, and humans.

Human Social Evolution: A Comparison of Hunter-gatherer and Chimpanzee Social Organization

Robert Layton and Sean O'Hara

in Social Brain, Distributed Mind

This chapter compares the social behaviour of human hunter-gatherers with that of the better-studied chimpanzee species, Pan troglodytes, in an attempt to pinpoint the unique features of human social ... More

This chapter compares the social behaviour of human hunter-gatherers with that of the better-studied chimpanzee species, Pan troglodytes, in an attempt to pinpoint the unique features of human social evolution. Although hunter-gatherers and chimpanzees living in central Africa have similar body weights, humans live at much lower population densities due to their greater dependence on predation. Human foraging parties have longer duration than those of chimpanzees, lasting hours rather than minutes, and a higher level of mutual dependence, through the division of labour between men (hunting) and women (gathering); which is in turn related to pair-bonding, and meat sharing to reduce the risk of individual hunters' failure on any particular day. The band appears to be a uniquely human social unit that resolves the tension between greater dispersion and greater interdependence.Less

Seven Steps in the Evolution of the Human Imagination

STEVEN MITHEN

in Imaginative Minds

The modern human is a product of six million years of evolution wherein it is assumed that the ancestor of man resembles that of a chimpanzee. This assumption is based on the similarities of the ... More

The modern human is a product of six million years of evolution wherein it is assumed that the ancestor of man resembles that of a chimpanzee. This assumption is based on the similarities of the ape-like brain size and post-cranial characteristics of the earliest hominid species to chimpanzees. Whilst it is unclear whether chimpanzees share the same foresight and contemplation of alternatives as with humans, it is nevertheless clear that chimpanzees lack creative imagination — an aspect of modern human imagination that sets humanity apart from its hominid ancestors. Creative imagination pertains to the ability to combine different forms of knowledge and ways of thinking to form creative and novel ideas. This chapter discusses seven critical steps in the evolution of the human imagination. These steps provide a clear picture of the gradual emergence of creative imagination in humans from their primitive origins as Homo sapiens some 200,000 years ago. This chronological evolution of the imaginative mind of humans involves both biological and cultural change that began soon after the divergence of the two lineages that led to modern humans and African apes.Less

The directed scratch: evidence for a referential gesture in chimpanzees? *

Simone Pika and John C. Mitani

in The Prehistory of Language

This chapter presents observations that suggest wild chimpanzees use a gesture, the directed scratch, in a referential fashion. Directed scratches share two crucial components with homesign systems. ... More

This chapter presents observations that suggest wild chimpanzees use a gesture, the directed scratch, in a referential fashion. Directed scratches share two crucial components with homesign systems. They involve some form of reference and may specify a distinct action, therefore qualifying as characterizing signs. Although homesign systems go a step beyond, by exhibiting simple grammatical structure and recursion, directed scratches may constitute the first step toward symbolic gestures. These findings are consistent with the hypothesis that gestures used by our closest living relatives might have been the crucial modality within which the evolutionary precursors of symbolic communication evolved. Additional comparative research investigating the factors triggering the development of referential gestures will be required to resolve what is unique to humans and what constitutes ‘fossil’ forms of human language or language abilities.Less

Salvage Primatology

Nicolas Langlitz

in Chimpanzee Culture Wars: Rethinking Human Nature alongside Japanese, European, and American Cultural Primatologists

This chapter assesses how cultural primatologists fought for the conservation and documentation of quickly dwindling chimpanzee communities. As Homo sapiens outcompeted Pan troglodytes in sub-Saharan ... More

This chapter assesses how cultural primatologists fought for the conservation and documentation of quickly dwindling chimpanzee communities. As Homo sapiens outcompeted Pan troglodytes in sub-Saharan Africa, Christophe Boesch, Tetsuro Matsuzawa, and the first generation of African primatologists forged alliances and made enemies in their attempts to prolong the coexistence of humans and apes for a few more years. In West Africa, the chimpanzee culture wars entwined scientific controversy with political crises and ethnic strife. In the face of the sixth mass extinction event in natural history, cultural primatologists set out to collect as much data about the lives of as many chimpanzee communities as possible. Boesch's Pan African Project almost quadrupled the number of documented chimpanzee cultures by switching from ethnographic observations of habituated groups to big data collection of camera trap recordings, fecal samples, and material artifacts. This collective effort at over thirty-five field sites built up an archive for future primatologists who might no longer have a chance to experience chimpanzee cultures firsthand. Epistemologically, the effort to build such an archive was based on an elegiac positivism, which minimized the theory-laden nature of recorded observations.Less

What Are the Genetic Differences That Made Us Human?

Norman A. Johnson

in Darwinian Detectives: Revealing the Natural History of Genes and Genomes

Humans differ from chimpanzees and other apes with respect to our large brains and our abilities to use language, among other differences. This chapter discusses several candidate genes involved in ... More

Humans differ from chimpanzees and other apes with respect to our large brains and our abilities to use language, among other differences. This chapter discusses several candidate genes involved in brain size and linguistic ability (e.g., FOXP2) upon which natural selection appears to have acted in the human lineage. The complete genome sequences of humans, chimpanzees, and mouse (an outgroup) allow evolutionary geneticists to determine what genetic changes have occurred along the lineage that led to us. The McDonald-Kreitman tests and other tests to detect positive selection (Chapter 4) allow for the determination of which changes have been involved in adaptive evolution.Less

Fine scale sequence diversity and signatures of selection

Julian C. Knight

in Human Genetic Diversity: Functional Consequences for Health and Disease

Genetic diversity observed in human populations provides unique insights into the selective pressures which have shaped our recent evolutionary past. Evidence to support this view is described in ... More

Genetic diversity observed in human populations provides unique insights into the selective pressures which have shaped our recent evolutionary past. Evidence to support this view is described in this chapter including concepts of genetic hitchhiking and selective sweeps, together with signatures of selection found from analysis of genetic variation. Insights gained from sequencing the chimpanzee and rhesus macaque genomes into human genetic diversity and selection is described. Evidence for selection from genetic studies of lactase persistence is reviewed for European, African, and Middle Eastern populations. The complex genetics of skin pigmentation is discussed, including the role of model organisms in identification of a human gene (SLC24A5) within which nucleotide diversity plays a major role in determining the light skinned pigmentation phenotype observed among Europeans. The chapter concludes with discussion of genome wide analyses using high density SNP panels in which many new loci showing evidence of selection are being identified.Less

Language in the Wild: Paleontological and Primatological Evidence for Gestural Origins

David F. Armstrong and Sherman E. Wilcox

in The Gestural Origin of Language

This chapter discusses current knowledge about the linguistic or language-like behaviour of modern great apes, especially chimpanzees (including bonobos) and gorillas. Evidence supports the idea that ... More

This chapter discusses current knowledge about the linguistic or language-like behaviour of modern great apes, especially chimpanzees (including bonobos) and gorillas. Evidence supports the idea that gesture-based language might have preceded speech in human phylogeny: (1) paleontological evidence for human anatomical evolution; (2) primatological evidence concerning the behaviour of the closest living relatives of human beings; and (3) neurological evidence concerning the organization of the substrates for linguistic behaviour in the brain.Less

The Comparative Neuropsychology of Tool Use in Primates with Specific Reference to Chimpanzees and Capuchin Monkeys

William D. Hopkins

in Primate Neuroethology

This chapter reviews behavioral and neurobiological data on tool use in primates. It shows that great apes, in particular chimpanzees, excel at tool use—especially generalizing principles to new ... More

This chapter reviews behavioral and neurobiological data on tool use in primates. It shows that great apes, in particular chimpanzees, excel at tool use—especially generalizing principles to new tool-using tasks and contexts. However, there is limited evidence that monkeys, even highly manual species such as capuchins, do so as readily. It is argued that this behavior is strongly associated with neuroanatomical changes that include the expansion of the cerebellum and interhemispheric connectivity.Less

Tissue‐Driven Hypothesis of Genomic Evolution

Xun Gu

in Statistical Theory and Methods for Evolutionary Genomics

Understanding the underlying regulatory mechanism is a fundamental step to exploring the emergence of genome complexity. An important issue is the role of tissue-specific factors in genomic ... More

Understanding the underlying regulatory mechanism is a fundamental step to exploring the emergence of genome complexity. An important issue is the role of tissue-specific factors in genomic evolution. Several studies have suggested that tissue-specific constraints may generate among tissue variation of expression divergence between humans and chimpanzees, between humans and mice, or between fruitflies. Duret and Mouchiroud showed that the rate of protein divergence was negatively associated with the tissue broadness of gene expression. This chapter first discusses the tissue-driven hypothesis, based on an explicit evolutionary model for providing testable predictions. This theory claims that stabilizing selections for both expression and sequence divergences may be affected simultaneously by common tissue factors. It then addresses an interesting problem about the expression evolution in the human brain since the separate development of humans and chimpanzees.Less

Other Complex Animals: Missed Opportunities?

Paul Waldau

in The Specter of Speciesism: Buddhist and Christian Views of Animals

Three groups of socially and cognitively complex nonhuman animals are discussed: elephants, cetaceans (whales and dolphins), and nonhuman great apes (gorillas, orangutans, bonobos, and chimpanzees). ... More

Three groups of socially and cognitively complex nonhuman animals are discussed: elephants, cetaceans (whales and dolphins), and nonhuman great apes (gorillas, orangutans, bonobos, and chimpanzees). These are assessed in terms of a constellation of general characteristics that lead to rich social relationships among complex individuals, which in turn leads to ethical importance or considerability. The limits of epistemology and sociology of knowledge regarding factual realities are analyzed. The central place of language in ethical debates is assessed.Less

Cognitive development in chimpanzees: A trade-off between memory and abstraction?

Tetsuro Matsuzawa

in The Making of Human Concepts

This chapter suggests that the strong, near-photographic memory of chimps for number may be one manifestation of a more general characteristic of a representational system that provides ... More

This chapter suggests that the strong, near-photographic memory of chimps for number may be one manifestation of a more general characteristic of a representational system that provides extraordinarily detailed records of visual scenes. Such a system may be viewed as adaptive in a cognitive niche in which rapid, categorical decisions need to be made about objects encountered (e.g. ripe vs. unripe food, friend vs. foe). By contrast, the human cognitive niche emphasizes linguistic descriptions of events that capture an abstract gist which can be communicated to others. In this sense, chimps may be likened to humans with autism who display weak central coherence (i.e. an eye for detail, but without the corresponding big-picture idea).Less

Chimpanzee Ethnography

Nicolas Langlitz

in Chimpanzee Culture Wars: Rethinking Human Nature alongside Japanese, European, and American Cultural Primatologists

This chapter examines how chimpanzee ethnographer Christophe Boesch and his group studied the social transmission of cultural traits in the chimpanzee communities of Taï Forest, Côte d'Ivoire. This ... More

This chapter examines how chimpanzee ethnographer Christophe Boesch and his group studied the social transmission of cultural traits in the chimpanzee communities of Taï Forest, Côte d'Ivoire. This ethnographic account of primatological fieldwork in the mid-2010s measures the historical distance to the 1960s when Jane Goodall and others sought to take part in the social life of great apes. In contemporary Taï, by contrast, disengaged observations of habituated chimpanzees served to protect both Pan and Homo. Despite the researchers' efforts to keep human–animal relations as neutral as possible, different chimpanzee communities related to their observers differently. In the forest, chimpanzee ethnography could hardly be distinguished from other forms of fieldwork. Boesch's approach to writing wild cultures turned out to share an important feature with humanities scholarship: references to philosophical classics gave it an intensely polemic bent rarely found in the scientific literature.Less

Japanese Syntheses

Nicolas Langlitz

in Chimpanzee Culture Wars: Rethinking Human Nature alongside Japanese, European, and American Cultural Primatologists

This chapter details how Pan and Homo came to share a life in the Japanese laboratory. Tetsuro Matsuzawa's Ai Project, named after his most famous nonhuman “research partner,” began as the Japanese ... More

This chapter details how Pan and Homo came to share a life in the Japanese laboratory. Tetsuro Matsuzawa's Ai Project, named after his most famous nonhuman “research partner,” began as the Japanese ape language project in 1976. But it soon morphed into a much broader comparative cognitive science program that provided a new face to Japanese primatology in the post-Imanishi era. For both methodological and ethical reasons, Matsuzawa sought to square tight experimental control with maximizing the captive chimpanzees' freedom to show spontaneous behavior. The often violent nature of chimpanzee social life strictly limited how much humans could take part. At Kumamoto Sanctuary, however, younger researchers from Matsuzawa's lineage had repurposed participant observation to apply delicate measuring instruments such as EEG caps or head-mounted eye tracker goggles to otherwise unruly apes. Thus, a new generation of Japanese primatologists integrated high-tech laboratory experiments, field observations in the laboratory, and participant observation — and eventually extended this synthetic primatology to the field.Less

Field Experiments with a Totem Animal

Nicolas Langlitz

in Chimpanzee Culture Wars: Rethinking Human Nature alongside Japanese, European, and American Cultural Primatologists

This chapter follows Tetsuro Matsuzawa and his coworkers to their outdoor laboratory in Bossou, Guinea. Revered as the totem animal of the Manon and deprived of almost all primary rainforest, the ... More

This chapter follows Tetsuro Matsuzawa and his coworkers to their outdoor laboratory in Bossou, Guinea. Revered as the totem animal of the Manon and deprived of almost all primary rainforest, the Bossou chimpanzees had learned to live on human crops in an agricultural landscape. In contrast to Christophe Boesch's emphasis on so-called wild cultures, Matsuzawa speculated that historically, this chimpanzee community might have learned from the human population how to crack the oil palm nuts that local farmers cultivated. Field experiments allowed the primatologists to study how female immigrants passed on their knowledge of how to crack other kinds of nuts within the group. At this point, Japanese cultural primatology contradicted the Manon's mythological understanding of “their” apes as a bounded community of nonnatural animals. Chimpanzee road crossings provided an opportunity for a natural — or really “naturecultural” — experiment in an anthropogenic environment. Ethnoprimatologists collaborating with Matsuzawa studied the ecological interface between humans and primates and used their insights for conservationist ends. After a political conflict over the protection of a small patch of primary forest on a sacred hill, the Japanese primatologists took over the Manon's position that the livelihood of the Bossou chimpanzees was better served by plantations than by a nature reserve.Less

Conclusion

Nicolas Langlitz

in Chimpanzee Culture Wars: Rethinking Human Nature alongside Japanese, European, and American Cultural Primatologists

This concluding chapter reviews what the previous chapters have revealed about cultural primatology. It compares the knowledge cultures of Christophe Boesch's field station, Michael Tomasello's ... More

This concluding chapter reviews what the previous chapters have revealed about cultural primatology. It compares the knowledge cultures of Christophe Boesch's field station, Michael Tomasello's laboratory, Tetsuro Matsuzawa's laboratory, and Matsuzawa's field station with each other to map a space of no-longer-available possibilities. Boesch's fieldwork on wild chimpanzees and Tomasello's laboratory experiments on captive chimpanzees contradicted each other regarding the capacity of Pan troglodytes for culture and cooperation. Boesch and Tomasello could not agree because the fieldworker doubted the ecological validity of the experimenter's findings, while the experimenter denied that field observations could provide any insights into what caused the observed behaviors, leaving chimpanzee ethnographers unable to rule out alternative explanations of supposedly cultural behaviors. Meanwhile, Matsuzawa's laboratory research at the Kyoto University Primate Research Institute and his field research in Bossou presented an interesting contrast to the disagreements between the two because he integrated lab and field in his own work. He studied the social learning of nut cracking through field observation, field experiment, participation observation, and controlled laboratory experiment — and conceived of his synthesis of all these approaches as an expression of Japanese holism.Less

Human Nature

Erika Lorraine Milam

in Creatures of Cain

This chapter looks at the scientific revelations produced by Jane Goodall's studies on great apes and the effects these studies had on the contentious field of sociobiology. When Jane Goodall and ... More

This chapter looks at the scientific revelations produced by Jane Goodall's studies on great apes and the effects these studies had on the contentious field of sociobiology. When Jane Goodall and David Hamburg argued for the biological similarities shared by humans and chimpanzees, they also articulated a vision of human nature. They based this vision on biological relatedness rather than on ecological sympathy and implicitly questioned the gendered roles and social hierarchies that characterized baboon behavior as the most appropriate primate model for reconstructing the social and behavioral norms that might have characterized early human life on the savannah. Goodall's early discoveries that chimpanzees manufactured tools, sticks with which to eat termites and masticated leaves with which to sponge up water, fit well with hypotheses that the origins of tool use lay in manufacturing aids for “gathering and processing food” rather than as weapons. But one of Hamburg's graduate students later recalled him warning her not to go overboard with sociobiology.Less