This chapter reviews the major theories of career transitions and the stages individuals progress through in their career. It then presents the Expert Transition Stages model, which tracks individuals through their career progression. It explains the six major career stages: (1) Studentship, (2) Performer, (3) Manager/coach, (4) Head of department, (5) Divisional lead, and (6) Chief. It focuses in particular on the five transitions between these stages and explains the nature of these transitions.

Life history theory has revolutionized the study of the evolved life course both across and within species. Humans are no exception. Life history theory provides nuance to claims of human uniqueness in the tree of life, including among mammals, and among primates in particular. This chapter first explains how life history theory delivers optimal trait characteristics given trade-offs that are defined by costs and benefits of different “solutions” to fitness-relevant problems. It reviews the current understanding of the evolution of the human life course, and the chapter evaluates explanations of long postreproductive life spans in human populations. It then provides a framework for modeling how selection pressures in different socioecological settings could shape the flexible expression of demographic, physiological, and even psychological traits in our species. Special emphasis is placed on the role that exogenous mortality and environmental unpredictability (and their cues) play on shaping a number of behavioral and physiological traits related to survival. Claims certainly outpace definitive tests, but after a half century, since life history theory was first introduced to the human life sciences, promising new directions are expanding the breadth of topics covered beyond demography, using multiple methods and spanning diverse disciplines.

Old English poems frequently present death and deathlike states as synonymous with a loss of strength and social usefulness. Given the omnipresence of death in the corpus, this chapter explores a broader range of texts than previous chapters, but it focuses particularly on poems concerned with cosmic order and disorder: wisdom catalogues – including The Fortunes of Men, Maxims I and II, and Solomon and Saturn II – and poetry on Doomsday, especially Christ in Judgement and Judgement Day II. All these texts suggest death’s resemblance to dormant physical states which ostensibly belong to the living, such as sleep and drunkenness, attributing a strangely lively quality to the condition of death itself. Death emerges as a true part of the life course, not purely in terms of continued social identity, but continued embodied experience – physically, it is marked by the kind of restriction and uselessness which accompany sleep and drunkenness, suggesting a kind of spectrum of usefulness and wastefulness which cuts across life and death.

Old English poetry sometimes suggests that normative life phases are experienced by each person in the same way, but it also disrupts this idea, directing our attention to the contingencies, surprises, and sudden shifts which shape each person’s life course. This study’s introductory chapter advances this central argument and establishes the literary-critical scope of the wider monograph. It also provides a theoretical grounding in sociological and philosophical approaches to the life course, as well as the theories of the nonhuman which inform this study’s inclusion of narratives of the lives of objects, animals, and other natural phenomena in its discussion of human ageing – illustrated by a case study of the ‘oyster’ riddle of the Exeter Book (Riddle 74). Relevant material-cultural and linguistic contexts are then surveyed, and the structure of the rest of the book outlined.

When the Riddles of the Exeter Book depict early life in the world, they show a striking lack of interest in birth imagery – rather than focusing on a moment of parturition (like many aenigmata in the Latin tradition), these texts instead present early life as a time of gradual growth, contingent on continued care provided by others. To contextualise these scenes in the Riddles, this chapter considers other Old English poems such as The Fortunes of Men, contemporary embryological thought, prose accounts of the ages of man and the world, and plastic art, including carved scenes of animals nurturing their young on an eleventh-century baptismal font and the depiction of Romulus and Remus on the Franks Casket. In the chapter’s later stages, it stresses another kind of transformation as the riddle-creatures take up a variety of social roles, frequently involving the perpetration, witnessing, and suffering of violence.

Medieval and modern accounts of old age are notable for the sheer abundance and diversity of the characteristics they identify. This chapter contemplates how contrasting qualities associated with old age actually connect in Old English poetry, dwelling particularly on the relationship between wisdom and sorrow, and introducing a new theoretical framework in the form of trauma theory. It points out the considerable presence of aged poets in the corpus, focusing particularly on Beowulf and Cynewulf’s epilogues. These texts stress that living into old age inevitably constitutes a kind of survival, one which involves witnessing destruction and terrible losses. The subsequently heightened intellectual, verbal, and creative capacity of the elderly sometimes resembles a kind of post-traumatic growth as understood within trauma theory. The parts of old age that are broadly positive (especially wisdom) and those that are negative (grief and loss) therefore emerge as inseparable.

Constructions of adulthood tend to be under-studied and under-theorised. In the face of this challenge, this chapter focuses on three vernacular verse hagiographies – commonly known as Guthlac A, Juliana, and Andreas – as well as Judith, which centres on a deuterocanonical Old Testament figure. In different ways, these poems all depict maturity as associated with increased social usefulness. Masculine youthful waywardness seems to be more of a source of interest to poets than similar behaviour in women, but it is an underappreciated quality of Old English poetry that unruly youth in women is represented; in particular, St Juliana rebels against societal expectations in a manner that is explicitly linked with her youth. Nonetheless, the seemingly later poems, Andreas and Judith, both problematise – in different ways–the idea that growth through adulthood is always, or even commonly, a linear, teleological drive towards physical and intellectual excellence.

Summarising this study’s findings, this concluding chapter explores a little-discussed and much-maligned text in their light: the relatively late, formally innovative, and greatly enigmatic Rhyming Poem of the Exeter Book. This poem is known for its apparently disorganised structure and ambiguous subject matter, moving rapidly between human and nonhuman referents, and operating on both a microcosmic and macrocosmic level. Yet The Rhyming Poem gains a great deal of clarity when approached as an articulation of a human life course, blurring with that of the world itself. Drawing on arguments built throughout the book, this final chapter sets out a new account of the poem, finding more coherence to its structure than scholars have previously detected, and pointing particularly to key connections between form and content in the poet’s bold use of rhyme to accentuate the sudden shifts and transformations of the life course.

For most people, the most obvious thought or image that sexual reproduction brings to mind is that of sexual intercourse, a mating between two individuals of opposite sexes, which will result in the birth of their common offspring. While biparental reproduction is certainly the most common mode of sexual reproduction among all eukaryotes, it is not the only one, and the way it is carried out can depart substantially, in many different ways, from the ‘canonical’ description above. What is common to all these modes is that two distinct sexually compatible individuals (parents) undertake a sexual exchange that leads to the generation of new individuals with a genetic constitution obtained from the association and/or the reassortment of those parents’ genomes. The key event in this mode of reproduction, technically called amphigony, is the fusion of two gametes or two nuclei functioning as gametes (syngamy), each produced by one parent, to form a zygote. While in species with anisogamy (i.e. with distinct male and female gametes; Chapter 4), only gametes of opposite sex are compatible, the two individuals that produce them are not necessarily a male and a female.

We are all familiar with the changes in an organism during development, followed by its reproduction, which are repeated generation after generation. Biologists describe this development–reproduction sequence as the life cycle: the series of transformations and reproductive events that, from a given stage of life of an organism, leads to the corresponding stage in a subsequent generation. We can describe a biological cycle as going from zygote to zygote, but also from adult to adult, or from embryo to embryo: in a cyclical process, the choice of the ‘initial phase’ is arbitrary or conventional, as the notorious ‘the chicken or the egg’ dilemma beautifully illustrates.

In the course of their lives, organisms spend time and energy on a number of activities and functions, of which reproduction is only one – think of growth, defence against predators and pests, and others. How many resources are used for reproduction, how much time is devoted to it and how this time is distributed over the course of life are all elements that characterize the different reproductive strategies. From an even wider perspective, in those organisms that at certain times in their lives can opt for one or another reproductive mode (e.g. sexual or asexual reproduction, as in many plants and many marine invertebrates), a reproductive strategy includes also this reproductive policy.

On February 1997 the birth was announced of a sheep named Dolly, the first mammal to be cloned from an adult cell of a mother individual. The event attracted enormous media attention. Dolly, born on 5 July 1996, actually had three ‘mothers’: one provided the egg (whose nucleus was removed), another the nucleus with the DNA picked out from a somatic cell (i.e. a cell of the body not specialized for reproduction), while the third mother carried the cloned embryo in her womb until parturition.

Ever since living beings arose from non-living organic compounds on a primordial planet, more than 3.5 billion years ago, a multitude of organisms has unceasingly flourished by means of the reproduction of pre-existing organisms. Through reproduction, living beings generate other material systems that to some extent are of the same kind as themselves. The succession of generations through reproduction is an essential element of the continuity of life. Not surprisingly, the ability to reproduce is acknowledged as one of the most important properties to characterize living systems. But let’s step back and put reproduction in a wider context, the endurance of material systems.

Acquiring the traits specific to a given sex, during early development or at another point during the life of an organism, is usually a complex process. Although the sex condition of an individual is conventionally defined based on the type of gametes it is able to produce (Chapter 4), the sex-specific phenotype is generally not limited to the organs of reproduction. Each of these characters can maintain a certain degree of independence from other sexual traits in the same organism, be subject to different developmental control, and show different degrees of sensitivity to the environment. Therefore, sexual differentiation extends to the development of the secondary sexual characters, which can be morphological, physiological, behavioural, or combinations of these. An exploration of this fascinating subject requires some preliminary clarification about systems and mechanisms of sex determination and sex differentiation.

In Chapter 1 we defined sexual reproduction as a form of reproduction that generates new individuals carrying a genome obtained by the association and/or the reassortment of genetic material from more than one source. In the most familiar form of sexual reproduction, the new genome is formed by the union of (partial) copies of the genomes of two parents through the fusion of two special cells produced for that purpose, the gametes, into a single cell, the zygote. This is the way most multicellular eukaryotes, ourselves included, reproduce sexually.

A zygote does not necessarily derive from the fusion of gametes or gametic nuclei produced by different individuals. Both egg and sperm may instead be produced by the same individual, a sufficient simultaneous hermaphrodite (Chapter 4). In this case, the offspring has only one parent. However, the gametes that merge are the products of independent processes of meiosis undergone by different germ cells, although in the same individual: this distinguishes self-fertilization (or selfing) from some forms of parthenogenesis where there is the fusion of two of the four nuclei deriving from the same meiosis, as we will see in the next sections (Figure 6.1).