The paper by Lande and Schemske explores the evolution of self-fertilization and inbreeding depression in plants. It presents genetic models that explain how inbreeding depression and self-fertilization rates evolve in plant populations. These models show that inbreeding depression, which is the reduction in fitness due to inbreeding, and self-fertilization are often alternative stable states in plant mating systems. The models suggest that species with a history of population bottlenecks or pollinator failure are more likely to evolve self-fertilization, while species with historically large, outcrossing populations are more likely to maintain outcrossing. The paper discusses the genetic mechanisms underlying inbreeding depression, including the effects of recessive and partially dominant lethal and sublethal mutations. It also examines the role of quantitative genetic variation in fitness traits, showing that inbreeding depression can be reduced by partial selfing. The models indicate that inbreeding depression is often caused by rare, largely recessive lethal and sublethal mutations, and that the presence of these mutations can significantly reduce the fitness of selfed progeny. The paper also addresses the evolution of self-fertilization in plants, showing that even in the absence of inbreeding depression, self-fertilization can spread through a population. However, inbreeding depression can prevent the evolution of self-fertilization in most species. The models suggest that the evolution of self-fertilization depends on the genetic change in the selfing rate occurring through small steps or major changes at a single locus. The paper also discusses the role of pollinator failure and population bottlenecks in reducing inbreeding depression. It shows that these events can significantly reduce the frequency of recessive lethal and sublethal mutations, thereby reducing inbreeding depression. The models suggest that the accumulation of inbreeding depression in a population can be reduced by sporadic pollinator failure or extreme population crashes. Overall, the paper provides a comprehensive analysis of the genetic models underlying the evolution of self-fertilization and inbreeding depression in plants. It shows that these processes are influenced by a variety of factors, including the history of the population, the level of inbreeding depression, and the genetic architecture of the species. The models suggest that there are two possible stable states for the mating system in plant populations: predominantly outcrossing or highly self-fertilizing. The paper concludes that these models can explain many of the classical observations on inbreeding depression and heterosis in plants.The paper by Lande and Schemske explores the evolution of self-fertilization and inbreeding depression in plants. It presents genetic models that explain how inbreeding depression and self-fertilization rates evolve in plant populations. These models show that inbreeding depression, which is the reduction in fitness due to inbreeding, and self-fertilization are often alternative stable states in plant mating systems. The models suggest that species with a history of population bottlenecks or pollinator failure are more likely to evolve self-fertilization, while species with historically large, outcrossing populations are more likely to maintain outcrossing. The paper discusses the genetic mechanisms underlying inbreeding depression, including the effects of recessive and partially dominant lethal and sublethal mutations. It also examines the role of quantitative genetic variation in fitness traits, showing that inbreeding depression can be reduced by partial selfing. The models indicate that inbreeding depression is often caused by rare, largely recessive lethal and sublethal mutations, and that the presence of these mutations can significantly reduce the fitness of selfed progeny. The paper also addresses the evolution of self-fertilization in plants, showing that even in the absence of inbreeding depression, self-fertilization can spread through a population. However, inbreeding depression can prevent the evolution of self-fertilization in most species. The models suggest that the evolution of self-fertilization depends on the genetic change in the selfing rate occurring through small steps or major changes at a single locus. The paper also discusses the role of pollinator failure and population bottlenecks in reducing inbreeding depression. It shows that these events can significantly reduce the frequency of recessive lethal and sublethal mutations, thereby reducing inbreeding depression. The models suggest that the accumulation of inbreeding depression in a population can be reduced by sporadic pollinator failure or extreme population crashes. Overall, the paper provides a comprehensive analysis of the genetic models underlying the evolution of self-fertilization and inbreeding depression in plants. It shows that these processes are influenced by a variety of factors, including the history of the population, the level of inbreeding depression, and the genetic architecture of the species. The models suggest that there are two possible stable states for the mating system in plant populations: predominantly outcrossing or highly self-fertilizing. The paper concludes that these models can explain many of the classical observations on inbreeding depression and heterosis in plants.