The origin of species diversity has challenged biologists for over two centuries. Allopatric speciation, the divergence of species resulting from geographical isolation, is well documented. However, sympatric speciation, divergence without geographical isolation, is highly controversial. Claims of sympatric speciation must demonstrate species sympatry, sister relationships, reproductive isolation, and that an earlier allopatric phase is highly unlikely. Here we provide clear support for sympatric speciation in a case study of two species of palm (Arecaceae) on an oceanic island. A large dated phylogenetic tree shows that the two species of Howea, endemic to the remote Lord Howe Island, are sister taxa and diverged from each other well after the island was formed 6.9 million years ago. During fieldwork, we found a substantial disjunction in flowering time that is correlated with soil preference. In addition, a genome scan indicates that few genetic loci are more divergent between the two species than expected under neutrality, a finding consistent with models of sympatric speciation involving disruptive/divergent selection. This case study of sympatric speciation in plants provides an opportunity for refining theoretical models on the origin of species, and new impetus for exploring putative plant and animal examples on oceanic islands.

Population viability analysis (PVA) has become a commonly used tool in endangered species management. There is no single process that constitutes PVA, but all approaches have in common an assessment of a population's risk of extinction (or quasi extinction) or its projected population growth either under current conditions or expected from proposed management. As model sophistication increases, and software programs that facilitate PVA without the need for modeling expertise become more available, there is greater potential for the misuse of models and increased confusion over interpreting their results. Consequently, we discuss the practical use and limitations of PVA in conservation planning, and we discuss some emerging issues of PVA. We review extant issues that have become prominent in PVA, including spatially explicit modeling, sensitivity analysis, incorporating genetics into PVA, PVA in plants, and PVA software packages, but our coverage of emerging issues is not comprehensive. We conclude that PVA is a powerful tool in conservation biology for comparing alternative research plans and relative extinction risks among species, but we suggest caution in its use: (1) because PVA is a model, its validity depends on the appropriateness of the model's structure and data quality; (2) results should be presented with appropriate assessment of confidence; (3) model construction and results should be subject to external review, and (4) model structure, input, and results should be treated as hypotheses to be tested. We also suggest (5) restricting the definition of PVA to development of a formal quantitative model, (6) focusing more research on determining how pervasive densitydependence feedback is across species, and (7) not using PVA to determine minimum population size or (8) the specific probability of reaching extinction. The most appropriate use of PVA may be for comparing the relative effects of potential management actions on population growth or persistence. Uso y Temas Emergentes del Análisis de Viabilidad PoblacionalResumen: El análisis de viabilidad poblacional (AVP) es una herramienta de uso común en el manejo de especies en peligro. No hay un proceso único que constituya al AVP, pero todos los enfoques tienen en común la estimación del riesgo de extinción (o cuasi extinción) o la proyección del crecimiento poblacional, ya sea bajo las condiciones actuales o las esperadas del manejo propuesto. A medida que aumenta la sofisticación del modelo, y que se dispone de programas de cómputo que facilitan el AVP sin necesidad de experiencia en modelaje, hay una mayor posibilidad de desaprovechar el modelo y una mayor confusión en la interpretación de los resultados. En consecuencia, discutimos el uso práctico y las limitaciones del AVP en la planificación de conservación y discutimos algunos temas emergentes del AVP. Revisamos temas vigentes que son prominentes en el AVP, incluyendo el modelaje espacialmente explícito, el análisis de sensibilidad, la inclusión de la genética en el AVP, AVP en plantas y paquetes...

The high diversity of mutualisms has probably limited the development of a general theory about their evolution and their stability. Here we review conflicts of interests occurring in the 13 known nursery pollination systems, where pollinators reproduce within the inflorescence they pollinate. We found three main conflicts of interest between mutualists that correspond to the following evolutionary questions: 1) Why do plants not kill their pollinators’ larvae? 2) Why do pollinators visit deceptive flowers? and 3) Why do pollinators pollinate? We show that the reproductive system of the plant is strongly correlated not only with the set of conflicts of interests that actually occur but also with the proximal resolution of these conflicts. In many cases the evolutionary stability of nursery pollination mutualisms relies on the avoidance of intra‐specific competition among pollinator larvae. This stabilizing factor could perhaps also explain the absence of overexploitation in other mutualisms.

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