Biology subjects

Rader, J. A.

Publications and source records attributed to Rader, J. A..

4 recordsLinked to original sources

bioRxiv2023

PhyloMatcher: a tool for resolving conflicts in taxonomic nomenclature

SummaryLarge-scale comparative studies rely on the application of both phylogenetic trees and phenotypic data, both of which come from a variety of sources, but due to the changing nature of phylogenetic classification over time, many taxon names in comparative datasets do not match the nomenclature in phylogenetic trees. Manual curation of taxonomic synonyms in large comparative datasets can be daunting. To address this issue, we introduce PhyloMatcher, a tool which allows for programmatic querying of two commonly used taxonomic databases to find associated synonyms with given target species names. Availability and implementationPhyloMatcher is easily installed as a Python package with pip, or as a standalone GUI application. PhyloMatcher source code and documentation are freely available at https://github.com/Lswhiteh/PhyloMatcher, the GUI application can be downloaded from the Releases page. ContactLswhiteh@unc.edu Supplemental InformationWe provide documentation for PhyloMatcher, including walkthrough instructions for the GUI application on the Releases page of https://github.com/Lswhiteh/PhyloMatcher.

bioinformatics↗

bioRxiv2022

Isotopic niches do not follow the expectations of niche conservatism in the bird genus Cinclodes

Phenotypic traits are expected to be more similar among closely related species than among species that diverged long ago (all else being equal). This pattern, known as phylogenetic niche conservatism, also applies to traits that are important to determine the niche of species. To test this hypothesis on ecological niches, we analyzed isotopic data from 254 museum study skins from 12 of the 16 species of the bird genus Cinclodes and measured stable isotope ratios for four different elements: Carbon, Nitrogen, Hydrogen and Oxygen. We find that all traits, measured individually, or as a composite measurement, lack any phylogenetic signal, which in turn suggests a high level of lability in ecological niches. We compared these metrics to the measurements of morphological traits in the same genus and found that isotopic niches are uniquely evolutionarily labile compared to other traits. Our results suggest that, in Cinclodes, the realized niche evolves much faster than expected by the constraints of phylogenetic history and poses the question of whether this is a general pattern across the tree of life.

evolutionary biology↗

bioRxiv2022

Morphological evolution of bird wings follows a mechanical sensitivity gradient determined by the aerodynamics of flapping flight

The physical principles that govern the function of biological structures also mediate their evolution, but the evolutionary drivers of morphological traits within complex structures can be difficult to predict. We used morphological traits measured from 1096 3-dimensional bird wing scans from 178 species to test how two frameworks for relating morphology to evolution interact. We examined whether the modular organization of the wing into handwing and armwing regions, or the relationship between trait morphology and functional output (i.e. mechanical sensitivity, driven here by flapping flight aerodynamics) dominate evolutionary rate ({sigma}2) and mode. Our results support discretization of the armwing and handwing as morphological modules, but morphological disparity and{sigma} 2 varied continuously with the mechanical sensitivity gradient and were not modular. Thus, mechanical sensitivity should be considered an independent driver of evolutionary dynamics, distinct from morphological modularity. TeaserMechanical sensitivity drives wing shape evolution in birds and may be fundamental to the evolution of biomechanical systems.

evolutionary biology↗

bioRxiv2022

How Turkey vultures tune their airspeed to environmental and behavioral factors

Animals must tune their physical performance to changing environmental conditions, and the breadth of environmental tolerance may contribute to delineating the species geographic range. A common environmental challenge that flying animals face is the reduction of air density at high elevation and a reduction in the effectiveness of lift production that accompanies it. Turkey vultures (Cathartes aura) inhabit a >3000 m elevation range, and fly considerably higher, necessitating that they compensate for air density differences through behavior, physiology, or biomechanics. We predicted that birds flying at high elevation would demonstrate higher median flight speeds while maintaining similar glide angles. We used 3-dimensional videography to track Turkey vultures flying at three elevations and found a negative relationship between median airspeed and air density that matched our prediction. Additionally, neither the ratio of horizontal speed to sinking speed nor flapping behavior varied with air density. These results were robust to varying flight behavior (climbing vs. level flight). Finally, we derived a glide polar from the free-flying vultures and showed that they are proficient at tuning their flight speed to minimize their cost of transport during straight-line flight, but transition to a minimum power strategy during gliding turns.

zoology↗