The branching of new species from an ancestral population requires the evolution of reproductive isolation between groups of individuals. Geographic separation of sub-populations by natural barriers, if sustained for sufficiently long times, may lead to the accumulation of independent genetic changes in each group and to mating incompatibilities (Mayr, 2001; Fitzpatrick et al., 2009). A similar...

We employ a simple model to show that social selection can lead to prezygotic reproductive isolation. The evolution of social discrimination causes the congealing of phenotypically similar individuals into different, spatially distinct tribes. However, tribal formation is only obtained for certain types of social behavior: altruistic and selfish acts can produce tribes, whereas spiteful and mut...

When 2 or more people believe that they are having an identical subjective experience, they believe that they “I-share.” I-sharing fosters connectedness (Pinel, Long, Landau, Alexander, & Pyszczynski, 2006), overcomes group boundaries (Pinel & Long, 2012), and facilitates prosocial behaviors (Huneke & Pinel, 2015; Johnson, Pinel, & Long, 2014). After reviewing the construct of I-sharing, the re...

Theoretical considerations suggest that the option of waiting under conditions of uncertainty affects the relative importance of firm-level productivity and distance-related transaction costs as driving forces of FDI. Yet the timing of FDI has received little attention in the empirical literature on FDI determinants. To help close this gap we analyze FDI decisions by German firms with and witho...

We present a likelihood-based statistical method for examining the pattern or rate of evolution of reproductive isolation. The method uses large empirical datasets to estimate, for a given clade, the average duration of two phases in the divergence of populations. The first phase is a lag phase and refers to the period during which lineages diverge but no detectable reproductive isolation evolv...

Sexual selection is proposed to be an important driver of diversification in animal systems, yet previous tests of this hypothesis have produced mixed results and the mechanisms involved remain unclear. Here, we use a novel phylogenetic approach to assess the influence of sexual selection on patterns of evolutionary change during 84 recent speciation events across 23 passerine bird families. We...

A long-standing question in evolutionary biology is what defines a species. The biological species concept considers a species as a population of individuals that interbreeds freely and produces viable offspring. Therefore, reproductive isolation is the essence of species. Hybrid necrosis is one form of post-zygotic reproductive isolation. In this chapter, we summarize what is known to date abo...