Does evolutionary biology contribute to ethics?

Human propensities that are the products of Darwinian evolution may combine to generate a form of social behavior that is not itself a direct result of such pressure. This possibility may provide a satisfying explanation for the origin of socially transmitted rules such as the incest taboo. Similarly, the regulatory processes of development that generated adaptations to the environment in the circumstances in which they evolved can produce surprising and sometimes maladaptive consequences for the individual in modern conditions. These combinatorial aspects of social and developmental dynamics leave a subtle but not wholly uninteresting role for evolutionary biology in explaining the origins of human morality.     

Recent trends in evolutionary ethics: greenbeards!

In recent years, there has been growing awareness among evolutionary ethicists that systems of cooperation based upon “weak” reciprocity mechanisms (such as tit-for-tat) lack scalability, and are therefore inadequate to explain human ultrasociality. This has produced a shift toward models that strengthen the cooperative mechanism, by adding various forms of commitment or punishment. Unfortunately, the most prominent versions of this hypothesis wind up positing a discredited mechanism as the basis of human ultrasociality, viz. a “greenbeard.” This paper begins by explaining what a greenbeard is, and why evolutionary theorists are doubtful that such a mechanism could play a significant role in explaining human prosociality. It goes on to analyze several recent philosophical works in evolutionary ethics, in order to show how the suggestion that morality acts as a commitment device tacitly relies upon a greenbeard mechanism to explain human cooperation. It concludes by showing how some early scientific models in the “evolution of cooperation” literature, which introduced punishment as a device to enhance cooperation, also tacitly relied upon a greenbeard mechanism.     

Functional and evolutionary relationships of troponin C.

Striated muscle contraction is initiated when, following membrane depolarization, Ca(2+) binds to the low-affinity Ca(2+) binding sites of troponin C (TnC). The Ca(2+) activation of this protein results in a rearrangement of the components (troponin I, troponin T, and tropomyosin) of the thin filament, resulting in increased interaction between actin and myosin and the formation of cross bridges. The functional properties of this protein are therefore critical in determining the active properties of striated muscle. To date there are 61 known TnCs that have been cloned from 41 vertebrate and invertebrate species. In vertebrate species there are also distinct fast skeletal muscle and cardiac TnC proteins. While there is relatively high conservation of the amino acid sequence of TnC homologs between species and tissue types, there is wide variation in the functional properties of these proteins. To date there has been extensive study of the structure and function of this protein and how differences in these translate into the functional properties of muscles. The purpose of this work is to integrate these studies of TnC with phylogenetic analysis to investigate how changes in the sequence and function of this protein, integrate with the evolution of striated muscle.