Australopithecus afarensis endocasts suggest ape-like brain organization and prolonged brain growth

Human brains are three times larger, are organized differently, and mature for a longer period of time than those of our closest living relatives, the chimpanzees. Together, these characteristics are important for human cognition and social behavior, but their evolutionary origins remain unclear. To study brain growth and organization in the hominin species Australopithecus afarensis more than 3 million years ago, we scanned eight fossil crania using conventional and synchrotron computed tomography. We inferred key features of brain organization from endocranial imprints and explored the pattern of brain growth by combining new endocranial volume estimates with narrow age at death estimates for two infants. Contrary to previous claims, sulcal imprints reveal an ape-like brain organization and no features derived toward humans. A comparison of infant to adult endocranial volumes indicates protracted brain growth in A. afarensis, likely critical for the evolution of a long period of childhood learning in hominins

Introduction to Special Section: Careers in Context

[Excerpt] Career scholars regularly cite Hughes’ (1937: 413) dictum that the study careers as “the moving perspective in which persons orient themselves with reference to the social order, and of the typical sequences and concatenations of office – may be expected to reveal the nature and \u27working constitution\u27 of a society.” Yet the greater part of the careers literature typically ignores this by focusing, largely, on the careers of individuals and influencing factors mainly linked to the person and his or her immediate context, to the neglect of the broader context within which the careers are lived. However, large-scale economic and organizational changes that have affected most industrial societies in recent decades – the rising amount of business activity across national borders (Anderson & Cavanaugh, 2005), the increasingly global arena for entertainment and media, the influence of the internet in economic, social and political affairs, increased labor force participation by women and concomitant changes in family roles, and the emergence of distinctive forms of employment relations across countries (Whitley, 1999; Barley & Kunda, 2004) – make neglect of the social and political contexts in which careers unfold very problematic. These developments have reshaped the multitude of settings in which work careers are lived: the communities of organizations, occupations, geographical areas, and so on. Specifically, the broad social context that provides the canvas on which work careers are painted, rather than the immediate organizational context as discussed, for example, by Johns (2001), is an important, yet partly neglected factor for understanding work careers. The immediate context may, of course, form a link between career and the broader context. However, it is the latter and not the former type of context that is a primary object of interest in this respect. We suggest that research exploring the broad context within which work careers are lived helps us understand better the nature of career in an Internet-based, globalised economy and how these careers, in turn, influence developments in the context

Evolution of brain lateralization: A shared hominid pattern of endocranial asymmetry is much more variable in humans than in great apes

Brain lateralization is commonly interpreted as crucial for human brain function and cognition. However, as comparative studies among primates are rare, it is not known which aspects of lateralization are really uniquely human. Here, we quantify both pattern and magnitude of brain shape asymmetry based on endocranial imprints of the braincase in humans, chimpanzees, gorillas, and orangutans. Like previous studies, we found that humans were more asymmetric than chimpanzees, however so were gorillas and orangutans, highlighting the need to broaden the comparative framework for interpretation. We found that the average spatial asymmetry pattern, previously considered to be uniquely human, was shared among humans and apes. In humans, however, it was less directed, and different local asymmetries were less correlated. We, thus, found human asymmetry to be much more variable compared with that of apes. These findings likely reflect increased functional and developmental modularization of the human brain