EVOLUTION OF RELIGIOUS CAPACITY IN THE GENUS HOMO: ORIGINS AND BUILDING BLOCKS Item Type Article Authors Rappaport, Margaret Boone; Corbally, Christopher Citation Rappaport, M. B. and Corbally, C. (2018), EVOLUTION OF RELIGIOUS CAPACITY IN THE GENUS HOMO: ORIGINS AND BUILDING BLOCKS. Zygon®, 53: 123-158. doi:10.1111/zygo.12386 DOI 10.1111/zygo.12386 Publisher WILEY Journal ZYGON Rights © 2018 by the Joint Publication Board of Zygon. Download date 28/09/2021 04:07:18 Item License http://rightsstatements.org/vocab/InC/1.0/ Version Final accepted manuscript Link to Item http://hdl.handle.net/10150/628191 This is the accepted version of the following article: EVOLUTION OF RELIGIOUS CAPACITY IN THE GENUS HOMO: ORIGINS AND BUILDING BLOCKS by Margaret Boone Rappaport, Christopher J. Corbally, in Zygon: Journal of Religion and Science, vol. 53, no. 1 (March 2018), pp.123-158, which has been published in final form at https://authorservices.wiley.com/api/pdf/fullArticle/14854784. This article may be used for non-commercial purposes in accordance with the Wiley Self- Archiving Policy [https://authorservices.wiley.com/author-resources/Journal-Authors/licensing- open-access/open-access/self-archiving.html] Abstract. The large, ancient ape population of the Miocene reached across Eurasia and down into Africa. From this genetically diverse group, the chimpanzees, bonobos, gorillas, and humans evolved from populations of successively reduced size. Using the findings of genomics, population genetics, cognitive science, neuroscience, and archaeology, the authors construct a theoretical framework of evolutionary innovations without which religious capacity could not have emerged as it did. They begin with primate sociality and strength from a basic ape model, and then explore how the human line came to be the most adaptive and flexible of all, while coming from populations with reduced genetic variability. Their analysis then delves into the importance of neurological plasticity and a lengthening developmental trajectory, and points to their following article and the last building block: the expansion of the parietal areas, which allowed visuospatial reckoning, and imagined spaces and beings essential to human theologies. Approximate times for the major cognitive building blocks of religious capacity are given. Keywords: ape; bottleneck; cognitive evolution; effective population size; founder effect; genetic drift; natural selection; plasticity; population genetics; sociality. Margaret Boone Rappaport is an anthropologist, biologist, and co-founder of the Human Sentience Project, Tucson, AZ, USA; e-mail: [email protected]. Christopher J. Corbally, SJ, is an astronomer with the Vatican Observatory and Department of Astronomy, University of Arizona, Tucson, AZ, USA and co-founder of the Human Sentience Project; e-mail: [email protected]. 1 EVOLUTION OF RELIGIOUS CAPACITY IN THE GENUS HOMO: ORIGINS AND BUILDING BLOCKS Margaret Boone Rappaport, Christopher J. Corbally The world can sometimes seem a violent place, but we are steadily becoming a more democratic and peaceful species, more cooperative, kinder, more empathetic, and more generous, descended from more aggressive ancestors in our not-too-distant past. We are still being tamed by culture, and if there are genetic differences among us that map onto these more peaceable natures, they will be finding favor in our ranks. Mark Pagel, Wired for Culture (2012, 266) INTRODUCTION This is the first in a series of three papers whose purpose is to describe the theoretical underpinnings for an evolutionary model of the biological emergence of religious capacity in the genus Homo (Table 1). Because religious capacity is essentially a cognitive trait, and the timing of human cognition has become an issue (MacLean 2016), our emphasis is on the timing of adaptations at the root of human religious capacity. In this first paper in a series of three (Rappaport and Corbally 2018a), important building blocks are identified, probed, and set in place for a model that is presented more fully in the next paper, “Evolution of Religious Capacity in the Genus Homo: Cognitive Time Sequence” (Rappaport and Corbally 2018b). The latter explores additional genomic, neurological, and cognitive findings that support construction of our model for religious capacity’s biological evolution. A third paper in the series, “Evolution of Religious Capacity in the Genus Homo: Trait Complexity in Action through Compassion” (Rappaport and Corbally 2018c) includes an analysis of the very complex human capacity for compassion using the stages in our evolutionary model; application of neural reuse theory and interpretation of it in a Darwinian context; and finally, a teaching tool on religious capacity in early Homo sapiens. The action in the latter frames the phenotypic expression of the human trait of religious capacity and the human ability to form compassion, both now and in the past. We use the term “trait” in the sense used by biologists (Varki and Altheide 2005, their Table 1). We hasten to add that our term “building block” implies a collection of traits or characteristics that appear together and are generally discrete both through time and sometimes among related species. The “building block” implies discreteness, strength, and adaptive advantage, and they are useful in demonstrating a solid biological foundation for religious capacity. We use “building block” to imply an adaptation or a set of related adaptations that are reliably reproduced in a species or a series of species. 2 Table 1. Classification of the Order Primates, Commonly Known Forms Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Lemurs and lorises “lower primates” Tarsiers “monkeys” New World monkeys Old World monkeys Superfamily Hominoidea (lesser apes, great apes, humans) Family Hylobatidae: gibbons (lesser apes) Family Hominidae (great apes and humans) Subfamily Ponginae (orangutans) Subfamily Homininae (gorillas, chimpanzees, humans) Tribe Gorillini (gorillas) Tribe Hominini: (chimpanzees and humans) Genus Pan (chimpanzees and bonobos) Species Pan troglodydtes (chimpanzee) Species Pan paniscus (bonobo) Genus Homo (humans and extinct related forms) Species Homo habilis (extinct) Species Homo erectus (extinct) Species Homo heidelbergensis (extinct) Species Homo neanderthalensis (extinct) Species Homo sapiens Subspecies Homo sapiens idaltu (extinct) Subspecies Homo sapiens sapiens We hasten to add that our term “building block” implies a collection of traits or characteristics that appear together and are generally discrete both through time and sometimes among related species. The “building block” implies discreteness, strength, and adaptive advantage, and they are useful in demonstrating a solid biological foundation for religious capacity. We use “building block” to imply an adaptation or a set of related adaptations that are reliably reproduced in a species or a series of species. There is a naturally fuzzy quality to these building blocks because traits that are eventually called “human” may have very ancient genetic roots in our pre-sapiens ancestors. The building blocks appear variable because of the statistical methods used in population genetics, which is based on probability theory. We further explore this quality in fascinating detailed examples, below, and reveal that some members of Homo sapiens have gene copies that go back as much as two million years, maybe more. In a general way, we all have features that derive from the first primates, then the first apes, and then our closer ancestors, the earlier members of the genus Homo. 3 The human trait of religious capacity has very ancient roots – not religious behavior per se, but the roots of it. The “building block” is an analytic artifice that helps us image the most important evolutionary changes that led to a species with religious capacity, whether it finds overt expression in individuals or not. There is substantial overlap in these “building blocks,” which represent types of changes through time, although we consider them in their order of first appearance according to our model. It is especially important to note that religious capacity need not be expressed to be present and available in the biology of the population that constitutes our species today. Similarly, no human must learn to read in order for the cognitive capacity that allows us to learn to read to be a trait of our species (cf Colagè 2015; Rappaport and Corbally 2016). Our goal here is not to search for signs of “religion” in the fossil record of apes or in the archaeological record of early hominins, or, in the results of modern genomics. We are leery of simplistic answers to questions about religious capacity, and find claims of “God genes” and the like to be facile explanations that ignore how exceptionally elaborate human religious capacity is and how many brain capacities it may draw upon. We propose that the complexity of religious capacity has roots. When one adds evolutionary depth to the exploration of religious capacity’s underpinnings, the image that emerges is one of a rich texture of stepwise genetic changes through millions of years of adaptation to changing environments. Was there a single quantum jump that produced religion? Most assuredly, there was not. Were there adaptations without which religious capacity today would not exist, or would be very different? Most assuredly, there were. The Miocene ape radiation (Table 2) provided the genetic variability and the basic ape model that