The largest avian radiation - The Passeriformes as a model group for understanding global patterns of biological diversification
Friday seminar by Jon Fjeldså.
The Passeriformes (perching birds) comprise nearly 2/3 of all now living birds; although Gondwanic by origin, it has spread and diversified all over the World and has undergone a tremendous adaptive radiation. A comprehensive and time-calibrated molecular phylogeny can now be linked with species distributions and earth history data to produce new insights about the relative roles of history and current ecology in determining large-scale variation in biodiversity. On large spatial and temporal scales, diversification appears to take place in bursts, during within a short time window and associated with specific hotspot-like areas, mainly in tropical mountains and in archipelagos. These areas act as species pumps that provide recruitment for the broader regional faunas. Island biogeography has so far adopted the premise that colonization flows from larger (and biologically rich) to smaller sites, but the phylogenetic data suggest that some large radiations have started as island radiations or in island-like continental environments.