Publications by authors named "A Machac"

Explaining broad molecular, phenotypic and species biodiversity patterns necessitates a unifying framework spanning multiple evolutionary scales. Here we argue that although substantial effort has been made to reconcile microevolution and macroevolution, much work remains to identify the links between biological processes at play. We highlight four major questions of evolutionary biology whose solutions require conceptual bridges between micro and macroevolution.

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Sexual selection is considered one of the key processes that contribute to the emergence of new species. While the connection between sexual selection and speciation has been supported by comparative studies, the mechanisms that mediate this connection remain unresolved, especially in plants. Similarly, it is not clear how speciation processes within plant populations translate into large-scale speciation dynamics.

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Article Synopsis
  • The study explores how different traits in hummingbirds affect the rates of speciation, considering both the traits themselves and how quickly they evolve.
  • The researchers test two main ideas: one suggests that similar traits encourage speciation (trait conservatism), while the other argues that varied traits promote it (trait divergence).
  • Findings indicate that smaller hummingbirds with shorter bills and specific habitat preferences have faster speciation rates, particularly linked to the diversity of their ecological traits rather than their physical traits.
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Three prominent explanations have been proposed to explain the dramatic differences in species richness across regions and elevations, (i) time for speciation, (ii) diversification rates, and (iii) ecological limits. But the relative importance of these explanations and, especially, their interplay and possible synthesis remain largely elusive. Integrating diversification analyses, null models, and geographic information systems, I study avian richness across regions and elevations of the New World.

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