Prospects and challenges for parametric models in historical biogeographical inference

In historical biogeography, phylogenetic trees have long been used as tools for addressing a wide range of inference problems, from explaining common distribution patterns of species to reconstructing ancestral geographic ranges on branches of the tree of life. However, the potential utility of phylogenies for this purpose has yet to be fully realized, due in part to a lack of explicit conceptual links between processes underlying the evolution of geographic ranges and processes of phylogenetic tree growth. We suggest that statistical approaches that use parametric models to forge such links will stimulate integration and propel hypothesis-driven biogeographical inquiry in new directions. We highlight here two such approaches and describe how they represent early steps towards a more general framework for model-based historical biogeography that is based on likelihood as an optimality criterion, rather than having the traditional reliance on parsimony. The development of this framework will not be without significant challenges, particularly in balancing model complexity with statistical power, and these will be most apparent in studies of regions with many component areas and complex geological histories, such as the Mediterranean Basin. © 2009 Blackwell Publishing Ltd.We also thank the participants of ‘Developing an Integrative Algorithmic Method for Historical Biogeography’, a working group supported by NESCent (US NSF #EF-0423641)Peer Reviewe

Fossil-Informed Models Reveal a Boreotropical Origin and Divergent Evolutionary Trajectories in the Walnut Family (Juglandaceae).

Temperate woody plants in the Northern Hemisphere have long been known to exhibit high species richness in East Asia and North America and significantly lower diversity in Europe, but the causes of this pattern remain debated. Here, we quantify the roles of dispersal, niche evolution, and extinction in shaping the geographic diversity of the temperate woody plant family Juglandaceae (walnuts and their relatives). Integrating evidence from molecular, morphological, fossil, and (paleo)environmental data, we find strong support for a Boreotropical origin of the family with contrasting evolutionary trajectories between the temperate subfamily Juglandoideae and the tropical subfamily Engelhardioideae. Juglandoideae rapidly evolved frost tolerance when the global climate shifted to ice-house conditions from the Oligocene, with diversification at high latitudes especially in Europe and Asia during the Miocene. Subsequent range contraction at high latitudes and high levels of extinction in Europe driven by global cooling led to the current regional disparity in species diversity. Engelhardioideae showed temperature conservatism while adapting to increased humidity, tracking tropical climates to low latitudes since the middle Eocene with comparatively little diversification, perhaps due to high competition in the tropical zone. The biogeographic history of Juglandaceae shows that the North Atlantic land bridge and Europe played more critical roles than previously thought in linking the floras of East Asia and North America, and showcases the complex interplay among climate change, niche evolution, dispersal, and extinction that shaped the modern disjunct pattern of species richness in temperate woody plants. [Boreotropical origin; climatic niche evolution; disjunct distribution; dispersal; diversity anomaly; extinction; Juglandaceae.]

Biologia reprodutiva de Psychotria poeppigiana Mull. Arg. (Rubiaceae) em mata de galeria

Psychotria L. (Rubiaceae) é o gênero com mais espécies heterostílicas dentre as Angiospermas. O objetivo deste trabalho é descrever a biologia floral, fenologia, o sistema reprodutivo e os polinizadores de Psychotria poeppigiana Müll. Arg. As inflorescências são capitadas terminais, com brácteas vermelhas e flores amarelas apresentando dois morfos distintos: brevistiladas e longistiladas, caracterizadas por flores hermafroditas com diferentes comprimentos de estiletes e posicionamento oposto das anteras (hercogamia recíproca). Encontrou-se diferenças no tamanho das anteras, dos grãos de pólen e da superfície estigmática entre os morfotipos. Polinizações controladas mostraram que os morfotipos apresentam auto-incompatibilidade e intramorfo-incompatibilidade ao nível do estigma e do estilete. Os visitantes são pequenas vespas, abelhas, borboletas e beija-flores, que visitam as flores com maior freqüência no início da manhã. De acordo com a freqüência e eficiência no comportamento de transportar os grãos de pólen entre os morfos florais, o principal polinizador foi o beija-flor Thalurania furcata. O néctar é produzido em pequena quantidade (máximo de 8µl) e durante a abertura das flores, que ocorre entre 5 e 7h. A espécie forma agrupamentos devido à existência de reprodução vegetativa