Brian A. Lerch

• PhD Candidate at University of North Carolina at Chapel Hill

Over the past few decades, studies have provided strong evidence that the robust links between the social environment, health, and survival found in humans also extend to nonhuman social animals. A number of these studies emphasize the early life origins of these effects. For example, in several social mammals, more socially engaged mothers have in...

Most work on source‐sink dynamics in metacommunities assumes that species have minimal or no niche overlap and thus different sources and sinks. We explore the alternative possibility: competing species have an overlapping set of sources and sinks. Using both implicit‐space two‐patch (ordinary differential equations) and explicit‐space reaction–dif...

[This corrects the article DOI: 10.1371/journal.pbio.3002059.].

Several empirical examples and theoretical models suggest that the greenbeard effect may be an important mechanism in driving the evolution of altruism. However, previous theoretical models rely on assumptions such as spatial structure and specific sets of pleiotropic loci, the importance of which for the evolution of altruism has not been studied....

Over the past few decades studies have provided strong evidence that the robust links between the social environment, health, and survival found in humans also extend to non-human social animals. A number of these studies emphasize the early life origins of these effects. For example, in several social mammals, more socially engaged mothers have in...

Understanding patterns of diversification necessarily requires accounting for both the generation and the persistence of species. Formal models of speciation genetics, however, focus on the generation of new species without explicitly considering the maintenance of biodiversity (e.g., coexistence, the focus of ecological studies of diversity). Cons...

Whether natural selection leads to attachment in monogamous pair bonds has seldom been addressed. Operationally defining attachment as a behavioral modifier that decreases divorce probability with pair duration, we develop a model for the evolution of attachment. If divorce (the ending of a pair bond when both individuals survive to the next breedi...

Despite the importance of population structures throughout ecology, relatively little theoretical attention has been paid to understanding the implications of social groups for population dynamics. The dynamics of socially structured populations differ substantially from those of unstructured or metapopulation‐structured populations, because social...

Speciation research–the scientific field focused on understanding the origin and diversity of species–has a long and complex history. While relevant to one another, the specific goals and activities of speciation researchers are highly diverse, and scattered across a collection of different perspectives. Thus, our understanding of speciation will b...

Despite the well known scale‐dependency of ecological interactions, relatively little attention has been paid to understanding the dynamic interplay between various spatial scales. This is especially notable in metacommunity theory, where births and deaths dominate dynamics within patches (the local scale), and dispersal and environmental stochasti...

Predation plays a role in preventing the evolution of ever more complicated sexual displays, because such displays often increase an individual’s predation risk. Sexual selection theory, however, omits a key feature of predation in modeling costs to sexually selected traits: Predation is density dependent. As a result of this density dependence, pr...

Sexual selection has a rich history of mathematical models that consider why preferences favor one trait phenotype over another (for population genetic models) or what specific trait value is preferred (for quantitative genetic models). Less common is exploration of the evolution of choosiness or preference strength: that is, by how much a trait is...

The production of costly public goods (as distinct from metabolic byproducts) has largely been understood through the realization that spatial structure can minimize losses to non-producing “cheaters” by allowing for the positive assortment of producers. In well-mixed systems, where positive assortment is not possible, the stable production of publ...

The presence of same-sex sexual behavior across the animal kingdom is often viewed as unexpected. One explanation for its prevalence in some taxa is indiscriminate mating-a strategy wherein an individual does not attempt to determine the sex of its potential partner before attempting copulation. Indiscriminate mating has been argued to be the ances...

Despite the importance of population structures throughout ecology, relatively little theoretical attention has been paid to understanding the implications of social groups for population dynamics. The dynamics of socially structured populations differ substantially from those of unstructured or metapopulation-structured populations, because social...

Despite widespread interest in the evolution and implications of monogamy across taxa, less attention—especially theoret-ical—has been paid toward understanding the evolution of divorce (ending a socially monogamous pairing to find a new partner). Here, we develop a model of the evolution of divorce by females in a heterogeneous environment, where...

Whether and how selection can act on collectives rather than single entities has been a tumultuous issue in evolutionary biology for decades. Despite examples of multilevel selection, a simple framework is needed that makes explicit the constraints that lead to the emergence of a “group fitness function”. We use evolutionary game theory to show tha...

Many social groups are made up of complex social networks in which each individual associates with a distinct subset of its groupmates. If social groups become larger over time, competition often leads to a permanent group fission. During such fissions, complex social networks present a collective decision problem and a multidimensional optimizatio...

The widespread presence of same-sex sexual behaviour (SSB) has long been thought to pose an evolutionary conundrum, as participants in SSB suffer the cost of failing to reproduce after expending the time and energy to find a mate. The potential for SSB to occur as part of an optimal strategy has received less attention, although indiscriminate sexu...

The widespread presence of same-sex sexual behavior (SSB) has long been thought to pose an evolutionary conundrum [1-3], as participants in SSB suffer the cost of failing to reproduce after expending the time and energy to find a mate. The potential for SSB to occur as part of an optimal strategy has received almost no attention, although indiscrim...

The evolution of cooperation between conspecifics is a fundamental evolutionary puzzle, with much work focusing on the evolution of cooperative breeding. Surprisingly, although we expect cooperation to affect the population structures in which individuals interact, most studies fail to allow cooperation and population structure to coevolve. Here, w...

The role that spatial structure plays for determining reproductive outcomes of territorial breeders has been surprisingly understudied. Here, we show that an edge effect leads to a negative correlation between male and female reproductive success. Many territorial species have a mating system characterized by males establishing home ranges in the b...

Allee effects in group‐living species are common, but little is known about the way in which Allee effects at the group‐level scale up to influence population dynamics. Most notably, it remains unclear whether component Allee effects within groups (where some component of fitness in small groups decreases with decreasing group size) will translate...