In this article, I advance a novel hypothesis on the evolution of hominin bipedalism. I begin by arguing extensively for how the transition to bipedalism must have been problematic for hominins during the Neogene. Due to this and the fact that no other primate has made the unusual switch to bipedalism, it seems likely that the selection pressure towards bipedalism was unusually strong. With this in mind, I briefly lay out some of the most promising hypotheses (...) on the evolutionary origin of hominin bipedalism and show how most, if not all, fail in the face of the need for an unusually strong selection pressure. For example, some hypotheses maintain that hominins became bipedal so they could use their hands for carrying infants, food, or other valuable objects. But extant apes are able to carry objects in one of their front limbs (while walking with the other three), and thus it does not seem plausible that our hominin ancestors went through the troublesome transition to bipedalism just so they could carry objects a little more efficiently. After I show that past hypotheses are wanting in the face of this challenge, I argue that there is only one selection pressure powerful enough to instigate a strange and problematic evolutionary adaptation like bipedalism, and that is sexual selection. Specifically, from the fact that bipedal locomotion is an important strategy for intimidating others and ascending the dominance hierarchy in extant apes, I argue that for no particular selective reason bipedal locomotion became a signal for high fitness (much as a large and intricate tail became a signal for high fitness for peahens), and this led to the trait being continuously reinforced in spite of all its deleterious fitness consequences. (shrink)

This paper offers an analysis of work on human development in evolutionary anthropology from a Thomist perspective. I show that both fields view care for others as fundamental to human nature and interpret cooperative breeding as expression of the virtue of charity. I begin with an analysis of different approaches to the relationship between evolutionary anthropology and moral theory. I argue that ethical naturalism is the approach best suited to interdisciplinary dialogue, since it holds that natural facts are useful for (...) moral theory but do not encompass it. This forms the basis for a Thomist analysis of some key features of human evolution including bipedalism, higher encephalisation and extended childhood. In each case I explain how these parts of our nature contributed to the evolution of modern humans, and how each is reliant upon communal care. Finally, I offer three observations on these facts from a Thomist perspective. Firstly, that a good human life necessarily involves caring for others and being cared for ourselves. Secondly, that this is exemplified in the virtue of charity, which is the ground of all virtue. Finally, that the need for such care shows that human flourishing cannot be attained without divine aid. (shrink)

The evolution of arm-leg relationships presents something of a problem for embodied cognitive science. The affordances of habitual bipedalism and upright posture make our two sets of appendages and their interrelationships distinctively human, but these relations are largely neglected in evolutionary accounts of embodied cognition. Using a mixture of methods from historical linguistics, Cognitive Linguistics and linguistic anthropology to analyze data from languages around the world, this paper identifies a robust, dynamic set of part-whole relations that emerge across the (...) human waistline between upper and lower appendage sets cross-culturally. The general pattern—identified as “arm-leg syncretism”—provides a plausible primary source for the uniquely human penchant for creative analogy, or “double-scope conceptual blending”, said to underlie the human language faculty (Fauconnier and Turner 2002, 2008; Deely 2002; Anttila 2003; Bybee 2010). This account not only addresses a conspicuous gap in the literature but also enables us to better understand what it means to be human—including how we came to be unique among other species and how we are still vitally interrelated with other species. Deely (2010) blends both sides of this tension into a single phrase: “the semiotic animal”. The paper further develops this distinction by drawing attention to one of the roles upright posture played in the emergence of semiotic consciousness. (shrink)