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Full-Text Articles in Biology

Big Brains Stabilize Populations And Facilitate Colonization Of Variable Habitats In Birds, Trevor S. Fristoe, Andrew N. Iwaniuk, Carlos A. Botero Sep 2017

Big Brains Stabilize Populations And Facilitate Colonization Of Variable Habitats In Birds, Trevor S. Fristoe, Andrew N. Iwaniuk, Carlos A. Botero

Biology Faculty Publications & Presentations

The cognitive buffer hypothesis posits that environmental variability can be a major driver of the evolution of cognition because an enhanced ability to produce flexible behavioural responses facilitates coping with the unexpected. Although comparative evidence supports different aspects of this hypothesis, a direct connection between cognition and the ability to survive a variable and unpredictable environment has yet to be demonstrated. Here, we use complementary demographic and evolutionary analyses to show that among birds, the mechanistic premise of this hypothesis is well supported but the implied direction of causality is not. Specifically, we show that although population dynamics are more …


Negative Density Dependence Mediates Biodiversity–Productivity Relationships Across Scales, Joseph A. Lamanna, R Travis Belote, Laura A. Burkle, Christopher P. Catano, Jonathan A. Myers Jul 2017

Negative Density Dependence Mediates Biodiversity–Productivity Relationships Across Scales, Joseph A. Lamanna, R Travis Belote, Laura A. Burkle, Christopher P. Catano, Jonathan A. Myers

Biology Faculty Publications & Presentations

Regional species diversity generally increases with primary productivity whereas local diversity–productivity relationships are highly variable. This scale-dependence of the biodiversity–productivity relationship highlights the importance of understanding the mechanisms that govern variation in species composition among local communities, which is known as β-diversity. Hypotheses to explain changes in β-diversity with productivity invoke multiple mechanisms operating at local and regional scales, but the relative importance of these mechanisms is unknown. Here we show that changes in the strength of local density-dependent interactions within and among tree species explain changes in β-diversity across a subcontinental-productivity gradient. Stronger conspecific relative to …


Groundcover Community Assembly In High-Diversity Pine Savannas: Seed Arrival And Fire-Generated Environmental Filtering, Kyle E. Harms, Paul R. Gagnon, Heather A. Passmore, Jonathan A. Myers, William J. Platt Mar 2017

Groundcover Community Assembly In High-Diversity Pine Savannas: Seed Arrival And Fire-Generated Environmental Filtering, Kyle E. Harms, Paul R. Gagnon, Heather A. Passmore, Jonathan A. Myers, William J. Platt

Biology Faculty Publications & Presentations

Environmental filtering—abiotic and biotic constraints on the demographic performance of individual organisms—is a widespread mechanism of selection in communities. A given individual is “filtered out” (i.e., selectively removed) when environmental conditions or disturbances like fires preclude its survival and reproduction. Although interactions between these filters and dispersal from the regional species pool are thought to determine much about species composition locally, there have been relatively few studies of dispersal × filtering interactions in species-rich communities and fewer still where fire is also a primary selective agent. We experimentally manipulated dispersal and filtering by fire (pre-fire fuel loads and post-fire ash) …