Barrier Displacement on a Neutral Landscape: Toward a Theory of Continental Biogeography

摘要: Macroevolutionary theory posits three processes leading to lineage diversification and the formation of regional biotas: dispersal (species geographic range expansion), speciation splitting), extinction termination). The Theory Island Biogeography (TIB) predicts species richness values using just two these processes; extinction. Yet most on Earth live continents or continental shelves, dynamics evolutionary at scales are qualitatively different from those that govern biogeographic islands. Certain geomorphological operating perennially platforms displace barriers gene flow organismal dispersal, affect all terms macroevolutionary diversification. For example, uplift a dissected landscape river capture both merge separate portions adjacent areas, allowing larger ranges, vicariant smaller when sizes subdivided below minimum persistence threshold. TIB also does not predict many phylogenetic patterns widely observed in continentally distributed taxa, including: (i) power function-like species-area relationships; (ii) log-normal distribution sizes, which have restricted ranges (are endemic) few broad cosmopolitan); (iii) mid-domain effects with more toward center, early-branching, species-poor clades periphery; (iv) exponential rates net log-linear accumulation lineages through geological time; (v) relationships between species-richness clade diversity, species-rich. Current provide robust mechanistic framework connect seemingly disparate patterns. Here we present SEAMLESS (Spatially Explicit Area Model Landscape Evolution by SimulationS) generates moving continuous, neutral landscape. is (LEM) treats as functionally equivalent respect model parameters. differs other model-based methods (e.g., Lagrange, GeoSSE, BayArea, BioGeoBEARS) modeling properties rather than evolution continuous landscape, along branches phylogeny. shows how required maintain avoid clade-wide extinction, demonstrates ancestral size richness, provides unified explanation for suite commonly listed above. explains simple barrier-displacement mechanism affects under conditions, advanced here formulation general biogeography. [Diversification, geodispersal, macroevolution, capture, vicariance.].