scholarly journals Testing Hypotheses of Correlated Evolution Using Phylogenetically Independent Contrasts: Sensitivity to Deviations from Brownian Motion

1996 ◽  
Vol 45 (1) ◽  
pp. 27-47 ◽  
Author(s):  
Ramón Díaz-Uriarte ◽  
Theodore Garland
Keyword(s):  
Brownian Motion ◽  
Independent Contrasts ◽  
Correlated Evolution ◽  
Testing Hypotheses ◽  
Phylogenetically Independent Contrasts

scholarly journals Long-legged bees make adaptive leaps: linking adaptation to coevolution in a plant–pollinator network

2017 ◽  
Vol 284 (1862) ◽  
pp. 20171707 ◽  
Author(s):  
Anton Pauw ◽  
Belinda Kahnt ◽  
Michael Kuhlmann ◽  
Denis Michez ◽  
Graham A. Montgomery ◽  
...  
Keyword(s):  
Plant Species ◽  
Evolutionary Divergence ◽  
Large Network ◽  
Independent Contrasts ◽  
Leg Length ◽  
Phylogenetically Independent Contrasts ◽  
Explained Variance ◽  
Spur Length ◽  
Plant Pollinator ◽  
Selective Environment

Adaptation is evolution in response to natural selection. Hence, an adaptation is expected to originate simultaneously with the acquisition of a particular selective environment. Here we test whether long legs evolve in oil-collecting Rediviva bees when they come under selection by long-spurred, oil-secreting flowers. To quantify the selective environment, we drew a large network of the interactions between Rediviva species and oil-secreting plant species. The selective environment of each bee species was summarized as the average spur length of the interacting plant species weighted by interaction frequency. Using phylogenetically independent contrasts, we calculated divergence in selective environment and evolutionary divergence in leg length between sister species (and sister clades) of Rediviva . We found that change in the selective environment explained 80% of evolutionary change in leg length, with change in body size contributing an additional 6% of uniquely explained variance. The result is one of four proposed steps in testing for plant–pollinator coevolution.

scholarly journals Nonlinear relationships and phylogenetically independent contrasts

2004 ◽  
Vol 17 (3) ◽  
pp. 709-715 ◽  
Author(s):  
S. Quader ◽  
K. Isvaran ◽  
R. E. Hale ◽  
B. G. Miner ◽  
N. E. Seavy
Keyword(s):  
Independent Contrasts ◽  
Nonlinear Relationships ◽  
Phylogenetically Independent Contrasts

Associated evolution of bipedality and cursoriality among Triassic archosaurs: a phylogenetically controlled evaluation

Paleobiology ◽  
2012 ◽  
Vol 38 (3) ◽  
pp. 474-485 ◽  
Author(s):  
Tai Kubo ◽  
Mugino O. Kubo
Keyword(s):  
Comparative Analysis ◽  
Relative Length ◽  
Independent Contrasts ◽  
Avian Flight ◽  
Phylogenetically Independent Contrasts ◽  
Controlled Evaluation

Bipedalism evolved more than twice among archosaurs, and it is a characteristic of basal dinosaurs and a prerequisite for avian flight. Nevertheless, the reasons for the evolution of bipedalism among archosaurs have barely been investigated. Comparative analysis using phylogenetically independent contrasts showed a significant correlation between bipedality (relative length of forelimb) and cursoriality (relative length of metatarsal III) among Triassic archosaurs. This result indicates that, among Triassic archosaurs, bipeds could run faster than quadrupeds. Bipedalism is probably an adaptation for cursoriality among archosaurs, which may explain why bipedalism evolved convergently in the crocodilian and bird lineages. This result also indicates that the means of acquiring cursoriality may differ between archosaurs and mammals.

Freshwater-to-marine transitions may explain the evolution of herbivory in the subgenus Mollienesia (genus Poecilia, mollies and guppies)

2019 ◽  
Vol 127 (4) ◽  
pp. 742-761 ◽  
Author(s):  
Jessica L Sanchez ◽  
Heather D Bracken-Grissom ◽  
Joel C Trexler
Keyword(s):  
Independent Contrasts ◽  
Diversification Rates ◽  
Ecosystem Boundaries ◽  
Evolutionary Diversification ◽  
Dietary Preferences ◽  
Phylogenetically Independent Contrasts ◽  
Habitat Transition ◽  
Saline Habitats

Abstract The ability of organisms to cross ecosystem boundaries is an important catalyst of evolutionary diversification. The genus Poecilia (mollies and guppies) is an excellent system for studying ecosystem transitions because species display a range of salinity and dietary preferences, with herbivory concentrated in the subgenus Mollienesia. We reconstructed ancestral habitats and diets across a phylogeny of the genus Poecilia, evaluated diversification rates and used phylogenetically independent contrasts to determine whether diet evolved in response to habitat transition in this group. The results suggest that ancestors of subgenus Mollienesia were exclusively herbivorous, whereas ancestral diets of other Poecilia included animals. We found that transitions across euryhaline boundaries occurred at least once in this group, probably after the divergence of the subgenus Mollienesia. Furthermore, increased salinity affiliation explained 24% of the decrease in animals in the gut, and jaw morphology was associated with the percentage of animals in the gut, but not with the percentage of species occupying saline habitats. These findings suggest that in the genus Poecilia, herbivory evolved in association with transitions from fresh to euryhaline habitats, and jaw morphology evolved in response to the appearance of herbivory. These results provide a rare example of increased diet diversification associated with the transition from freshwater to euryhaline habitats.

Independent evolution of squamate olfaction and vomerolfaction and correlated evolution of vomerolfaction and lingual structure

1997 ◽  
Vol 18 (1) ◽  
pp. 85-105 ◽  
Author(s):  
William E. Cooper
Keyword(s):  
Ventral Side ◽  
Taste Buds ◽  
Taste Bud ◽  
Independent Contrasts ◽  
Sampling Device ◽  
Correlated Evolution ◽  
Environmental Surfaces ◽  
Vomeronasal Receptors ◽  
Chemical Stimuli ◽  
Chemoreceptor Cells

AbstractThe comparative abundances of chemoreceptor cells for olfaction and vomerolfaction, the sense mediated by the vomeronasal organs, were studied in numerous squamate families, with emphasis on lizards, and compared with abundance of lingual taste buds and aspects of lingual structure likely to be related to chemosensory sampling for vomerolfaction. Abundances of vomerolfactory receptors vary greatly among, but little within squamate families. Using Felsenstein's method of independent contrasts, the abundance of vomeronasal receptors is significantly correlated with size of lingual tines, degree of lingual elongation, and condition of sampling surfaces (pallets) on the ventral side of the tongue. This indicates that correlated evolution has occurred. An intimate relationship exists between the chemosensory organ and its primary sampling device, highlighting a lingual-vomeronasal complex that functions to sample and analyze chemical stimuli from external environmental surfaces. Attributes enhancing lingual facility for chemical sampling are forking, which permits scent-trailing by tropotaxis, and possibly elongation, which may permit greater extension beyond the mouth or enhance maneuverability. Ventral lingual pallets, surfaces that directly contact substrates during sampling, are large in forms having low abundances of vomerolfactory receptors, but are reduced and are eventually lost with progressive increases in vomerolfactory receptor abundance. Pallet condition is negatively correlated with tine size and lingual elongation. Large tines appear to take over the sampling function in forms lacking pallets. Lingual taste bud abundance is negatively correlated with vomerolfactory receptor abundance, forking, elongation, and positively with pallet condition. The negative correlation between the abundance of vomerolfactory receptors and lingual taste buds may be attributable to physical incompatibility between taste buds and specialized modifications of the foretongue for vomerolfactory sampling or to loss of opportunity for lingual taste buds to function in vomerolfactory specialists that lack lingual functions such as prey prehension, manipulation, and transport and in which the tongues are ensheathed while in the mouth. The abundances of olfactory and vomeronasal chemoreceptor cells are uncorrelated using Felsenstein's method. Thus, olfaction appears to have evolved independently of vomerolfaction.

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