Identifying Psychological Pathways to Polyvictimization: Evidence from a Longitudinal Cohort Study of Twins from the United Kingdom.

Objectives: Examine the extent to which cognitive/psychological characteristics predict later polyvictimization. We employ a twin-based design that allows us to test the social neurocriminology hypothesis that environmental factors influence brain-based characteristics and influence behaviors like victimization.

Methods: Using data from the Environmental Risk Longitudinal Twin Study ( = 1986), we capitalize on the natural experiment embedded in a discordant-twin design that allows for the adjustment of family environments and genetic factors.

Illegal tusk harvest and the decline of tusk size in the African elephant.

Harvesting of wild populations can cause the evolution of morphological, behavioral, and life history traits that may compromise natural or sexual selection. Despite the vulnerability of large mammals to rapid population decline from harvesting, the evolutionary effects of harvesting on mega-fauna have received limited attention. In elephants, illegal ivory harvesting disproportionately affects older age classes and males because they carry large tusks, but its' effects on tusk size for age or tusk size for stature are less understood.

Gene duplication and the environmental regulation of physiology and development.

When different life stages have different environmental tolerances, development needs to be regulated so that each life stage experiences environmental conditions that are suitable for it, if fitness is to be maintained. Restricting the timing of developmental transitions to occur under specific combinations of environmental conditions is therefore adaptively important. However, impeding development can itself incur demographic and fitness costs.

The evolution of embryonic gene expression in sea urchins.

Many evolutionary modifications in development and life history derive from changes in embryonic gene expression. However, the genetic variation affecting gene expression in natural populations is not well understood, nor are the evolutionary mechanisms that operate on that variation. The early embryonic gene network of the purple sea urchin (Strongylocentrotus purpuratus) has been studied in considerable detail, providing an informative basis for analyzing the developmental and evolutionary mechanisms that alter gene expression.