Abstract Detail


Simpson, Andrew [1].

Diversification in the Rosales at multiple taxonomic levels influenced by dispersal, geographic range size, and pre-existing species richness.

Geographic range size, because of its relationship with diversification and extinction, potentially links ecological and evolutionary processes. We use the MuSSE method (Multiple-State Speciation and Extinction) to explore the effects on genus-level diversification of two genus-level traits (geographic range size and within-genus proclivity to speciate, proxied by within-genus species richness), and two individual traits (seed dispersal mechanism and growth habit), using the angiosperm order Rosales as a study group. At the species-level, animal dispersal and herbaceous habit both enhance diversification rate; however, for herbaceous lineages, the effect of animal dispersal is primarily an increase in speciation rate, while in woody species, the effect of animal dispersal is a decrease in extinction rate. At the genus level, we find herbaceous taxa to have net positive diversification rates regardless of other character states. However, diversification rate variation is also explained by two interactions: (1) a three-way interaction between large geographic range, animal-mediated dispersal, and high within-genus species richness, whereby genera possessing all three traits have high diversification rates, and (2) a four-way interaction by which the three-way interaction is stronger in woody genera than in herbaceous genera. As with our species-level analysis, woody genera not possessing the three trait states preferentially become extinct. Colonization ability may underlie the interaction between dispersal type and range size and may influence diversification rates by decreasing extinction rates during late Cenozoic (especially Pleistocene) times of climate volatility. Thus, colonization ability could be used to predict future extinction risk to improve conservation success.

1 - Department Of Paleobiology, National Museum Of Natural History, Smithsonian Institution, Washington, DC, 20560, United States

seed dispersal
Species selection
Clade election.

Presentation Type: Poster Time and date to be determined
Number: PMC003
Abstract ID:742
Candidate for Awards:None

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