The Cambrian Explosion is one of the most fascinating periods in Earth’s prehistory, as here we first find animals in the fossil record. With the discovery of the Burgess Shale, we can get a sense of the enormous diversity in animals evolving in a relatively short time, as the appearance of complex multicellular organisms provided evolution with an open canvas. The chapter devotes some space to exploring the inferences made about trilobites, given the morphological diversity, social inferences, and informative anatomical structures we see in this group. With the evolution of animals, the chapter introduces the phylogeny of the large taxonomic groups, and describes the major transitions in the evolution of the animals, starting with the sponges and ending with the vertebrates. It reviews the evolution of the nervous system, contrasting the distributed neural network seen in cnidarians (i.e. jellyfish) with the central nervous system of vertebrates and arthropods. Finally, it goes into detail on the evolution of the notochord in the earliest known chordates.

The final chapter discusses the long-term prospects for the Earth, including demographic changes that are likely to have important long-term implications for humanity, such as the overall decrease in the birth rate, the trends towards increasing literacy, and the importance of educating and empowering women as a factor in the economic progression of societies (perhaps the strongest predictor of economic success in a society). It reviews some of the confounding influences retarding world progression (e.g. our inherent bias towards short-term decision-making, especially in the context of debates over responses to climate change), and how some societies have helped address them successfully. In general, much of human history is the struggle between our impulses and our intellect, and there are innumerable instances of historical ‘failure’, but trends generally point towards improved economics and human rights over the long-term arc of human history.

Modernity started with Darwin and probably reached its philosophical peak with Einstein. The appearance of modernity is associated with the rise of science as a dominant source of philosophical authority, and worldwide recognition of the rights of citizens, particularly women (the vote, birth control, etc.). For the first time, the orientation of philosophy was towards the future rather than the past, and ancient sources of knowledge, authority, and wisdom, were challenged. Some countries (e.g. Turkey under Ataturk) abandoned their past almost overnight. However, this is also the period of time when there were multiple challenges to the modern world view (based on democracy, the rights of citizens, and science). Religious reactionaries explicitly rejected modernity, whether it be in the form of creationist challenges to Darwinism or suppression of the burgeoning rights of women by the three monotheistic Abrahamic religions. Also, democracy as a model for government was challenged by fascism in the middle of the twentieth century, culminating in the mid-century wars of modernity: the Spanish Civil War and World War II. This chapter reviews the example of modern China, where the current government accepts some parts of traditional Western modernity while rejecting others.

After the Neolithic transition, arguably the most important economic shift was the industrial revolution. Prior to the industrial revolution, for the previous 10,000 years, the world relied (almost) exclusively on small-scale agriculture or pastoralism for economic production. The industrial revolution, starting largely with the development of the steam engine, had a profound effect on the material relationship of the individual to economic production, as individuals became part of industrial production. This change also had significant impacts on demographics: cities grew as the economics drove mass migrations away from rural areas to industrialized areas. Industrialization also had a long-lasting effect on politics, as workers organized to make improvements in working conditions and shift the power balance between labor and capital. Marxism was born of this struggle, and I explore the premises behind this philosophy, and the reasons for expansion as well as ultimate failure of this profoundly influential economic model. Here I speak to the contradictions between modern humanism and the authoritarian application of Marxism, drawing in the discussion on chaos and complexity and the difficulties with attempting central control on something as complex as a national economy.

Although largely accepted in animal biology, sociobiology has proven to be a controversial model for explaining human behavior. Nowadays sometimes termed ‘behavioral ecology’, the application of biological models to human behavior has the potential to explain a wide array of human instincts and actions. This chapter reviews the models for such putative human universals as violence, sexual reproduction strategies, coalition-building, and altruism, and compares them with similar models applied to animals. It also emphasizes that environment and culture provides critical influences on the ultimate expression of behavior: for example, across societies, mate preferences are partially mediated by society’s economic opportunities, so that culture can act as a buffer for underlying biological instincts. Since this topic is controversial, the chapter review the historical antecedents, starting with Plato’s theory of universals, through John Locke’s Enlightenment ideal, the ‘tabula rasa’, to Margaret Mead and Napoleon Chagnon in modern anthropology. Much of this debate has an underlying moral element, so the chapter discusses the naturalistic fallacy and point out the fact that our morality need not be determined in any way by potential evolutionary influences on instincts or behaviors. However, it also notes the potential logical pitfalls of treating humans as ‘special case’ animals.

This chapter is a broad outline of the timeline of the Big Bang and the formation of the universe and solar system. It discusses the relationship between energy and matter, and how elements are formed from simpler elements due to the application of energy and gravity. This chapter emphasizes the large scales of time and space, and also how energy and matter are distributed across the vastness of universe. Finally, it discusses our solar system and similarities to other distant solar systems with planets in the ‘habitable zones’, and the potential for life outside Earth.

The Enlightenment represents the first time since Democritus that philosophers began to systematically question religious explanations for material phenomenon, instead looking for strictly materialistic explanations that were consistent with our understanding of the temporal plane. In particular, this is when science began to challenge the power of the Western religious authorities, which also challenged the principle of rule by divine right. In addition to the appearance of religious skepticism and scientific explanations, this is the period when revolutions against inherited rule challenged the kings and queens of Europe. This period is also associated with a dramatic increase in literacy in Western countries, which makes an interesting contrast with, for example, China, where the complexity of the written language served as an obstacle to higher rates of literacy for several centuries. In general, high rates of literacy are inversely correlated with institutional power and correlated with personal liberty in citizens. The worldwide spread of democracy over the last 200 years is a direct result of intellectual changes associated with the Enlightenment, but the chapter also reviews why the transition to democracy has not been universal.

This chapter explains the conceptual transition from hard science to a scientific explanation for historical events. It contrasts historical narratives with testable explanatory models.

This chapter introduces some of the broader ideas and themes of the book, especially the importance of the scientific method as a route to understanding the material universe. It contrasts the scientific perspective with the perspectives in other academic and non-academic disciplines (e.g. the historical, religious, and moral perspectives on human behavior). It gives examples of the value of the scientific perspective, especially the fact that it does not allow for a privileged position, and that it is a relatively democratic form of knowledge. It discusss some historical objections to science, and also reviews some misuse of science, but also the types of topics science cannot address (morality, aesthetics, etc.).

For the last 5,000 years humans have been steadily transitioning to state/kingdom power structures. This chapter explains the demographic and political causes of the transition to institutional power, most frequently vested in lineages, and the ways in which institutional religions have supported institutional power in states and kingdoms. Personal and institutional power are inversely related in states and kingdoms, and this chapter explorea some examples of authoritarian and libertarian regimes, as well as the conflict within our own (US) society on these questions. Following on the idea of structural power, it reviews various aspects of institutional coercion (laws, taxes, conscription, slavery), as well as the ways institutions regulate the flow of information to control populations (the execution of William Tyndale, Spanish burning of Mayan texts, Nazi book burning, etc.). It finishes by discussing the expansion of empires and the resistance some populations show to externally imposed institutional authority.

The transition from a foraging lifestyle to structured political systems is one of the most momentous changes in the history of our species. This chapter reviews the various parameters that changed as a result of the transition to agriculture, including health, wealth, and power structures. There are a considerable number of debates over this transition, as researchers studying health, violence, political and personal power, and gender equity have studied it, with significant political implications in disciplines such as anthropology, economics, political science, and gender studies.

The Cambrian unleashed the forces of evolution, giving rise to new anatomical adaptations that still form parts of modern animal anatomy. The evolution of the mandible, hyoid cartilage, cricoid cartilage, and styloid ligament from the gill arches of a hagfish-like ancestor is one of the most consequential adaptations. In this time period we also see the evolution of the bony cranium of vertebrates, first seen in armored predators such as the large placoderm, Dunkleosteus. During the Devonian we see the evolution of vertebrate fish diversity and, importantly for land mammals, the appearance of the lobe-finned fishes and the first land animals with a full shoulder and pelvic girdle. Although this chapter provides a broad overview of animal evolution (from fish to amphibians to dinosaurs to mammals) over several hundred million years, the major message is that large adaptive radiations are often only possible in places where there is no competition, either because there is a new open adaptive space (as with amphibians) or because another previous group has suffered a major extinction. Life on earth, once fully established, is a zero-sum game, so for there to be winners there must be losers.

Evolution is responsible for all biological diversity on earth, so it is critical that the students understand precisely what evolution is and how we know that evolution is a fact. In this chapter the four causes of evolutionary change in populations are reviewed in some detail, relying partially on the lessons on genetics in Chapter 5. It particularly emphasizes evidence in the modern world for evolution, such as the evolution of antibiotic-resistant strains of bacteria, but also patterns seen in extant vertebrates documented in locations of significant environmental change over the last 200 years. This chapter also reviews the history of the discovery of evolution, and the intellectual antecedents that allowed Darwin to make his inference. It explores the appearance of the scientific worldview during the Renaissance and Enlightenment and how that worldview challenged (and continues to challenge) some religious and secular authorities.

Understanding economics is critical to understanding the history of humanity, from hunter-gatherers to today. Economics is the study of decision-making and how humans make decisions. Without understanding economics we cannot understand the trajectory of history over the last 10,000 years. This chapter reviews basic economic principles, and how economies have evolved through time. It discusses the economic principles of Adam Smith and Karl Marx, the differences between a market economy and a command economy, and the political and historical implications of the clash between those two models.

This chapter introduces the idea of Earth’s timeline and the six major epochs. The principle of radiometric dating is introduced here, to provide the absolute age of the earth and other geological features. This chapter also provides a brief outline of geological principles, and especially emphasizes the importance of plate tectonics and continental drift, to explain the contours and positions of the continents, oceans, mountain ranges, and rifts. It introduces the idea of understanding the importance of geology/climate in driving biological evolution.

The two major questions posed by this chapter are: What is life and how do we define and identify it? How did life originate? It discusses different definitions of life and the role of entropy as a constraint. It discusses some forms that may or may not meet differing definitions of life (e.g. prions, viruses). The various hypotheses, studies, and discoveries pertaining to the origins of life are explored, including the Miller–Urey experiment, the Murcheson meteorite, and more recent NASA experiments relating to the potential origins of DNA and complex proteins. It also discusses the conditions on Earth during the origins of life, and presents the current hypotheses for the origins of water on this planet. It also reviews the candidates for the earliest life on Earth discovered in the fossil record, and explores just how we would identify the oldest life.