scholarly journals Losses of female song with changes from tropical to temperate breeding in the New World blackbirds

2009 ◽  
Vol 276 (1664) ◽  
pp. 1971-1980 ◽  
Author(s):  
J. Jordan Price ◽  
Scott M. Lanyon ◽  
Kevin E. Omland
Keyword(s):  
Sexual Selection ◽  
New World ◽  
Female Song ◽  
Complex Song ◽  
Evolutionary Changes ◽  
Apparent Relationship ◽  
Song Production ◽  
Selection For ◽  
The Tropics

Birds in which both sexes produce complex songs are thought to be more common in the tropics than in temperate areas, where typically only males sing. Yet the role of phylogeny in this apparent relationship between female song and latitude has never been examined. Here, we reconstruct evolutionary changes in female song and breeding latitude in the New World blackbirds (Icteridae), a family with both temperate and tropical representatives. We provide strong evidence that members of this group have moved repeatedly from tropical to temperate breeding ranges and, furthermore, that these range shifts were associated with losses of female song more often than expected by chance. This historical perspective suggests that male-biased song production in many temperate species is the result not of sexual selection for complex song in males but of selection against such songs in females. Our results provide new insights into the differences we see today between tropical and temperate songbirds, and suggest that the role of sexual selection in the evolution of bird song might not be as simple as we think.

scholarly journals Sexual size dimorphism and sexual selection in artiodactyls

2020 ◽  
Vol 31 (3) ◽  
pp. 792-797
Author(s):  
Marcelo H Cassini
Keyword(s):  
Sexual Selection ◽  
Sexual Dimorphism ◽  
Group Size ◽  
Sexual Size Dimorphism ◽  
Alternative Hypothesis ◽  
Mammalian Species ◽  
Generalized Least Squares ◽  
Size Dimorphism ◽  
Selection For

Abstract Sexual size dimorphism is biased toward males in most mammalian species. The most common explanation is precopulatory intramale sexual selection. Large males win fights and mate more frequently. In artiodactyls, previous tests of this hypothesis consisted of interspecific correlations of sexual dimorphism with group size as a surrogate for the intensity of sexual selection (Is). However, group size is not a proper measure of sexual selection for several reasons as is largely recognized in other mammalian taxa. I conducted an interspecific test on the role of sexual selection in the evolution of sexual dimorphism using the variance in genetic paternity as a proxy for the Is. I reviewed the literature and found 17 studies that allowed estimating Is= V/(W2), where V and W are the variance and mean number of offspring per male, respectively. A phylogenetic generalized least squares analysis indicated that dimorphism (Wm/Wf) showed a significant positive regression with the intensity of sexual selection but not group size (multiple r2= 0.40; F3,17= 12.78, P = 0.002). This result suggests that sexual selection may have played a role in the evolution of sexual size dimorphism in Artiodactyla. An alternative hypothesis based on natural selection is discussed.

scholarly journals Animal personalities and their implications for complex signaling

2014 ◽  
Vol 60 (3) ◽  
pp. 381-386 ◽  
Author(s):  
Nicholas Dirienzo ◽  
Ann V Hedrick
Keyword(s):  
Sexual Selection ◽  
Behavioral Ecology ◽  
Ecological Processes ◽  
Signaling Systems ◽  
Signaling Complex ◽  
Selection For ◽  
Complex Signaling ◽  
Animal Personalities ◽  
Signaling Interactions

Abstract Animal personalities have been a major focus of behavioral ecology over the past decade. Consistent individual differences in behavior have been found across taxa, and have been shown to influence a range of ecological processes. The role of personalities in sexual selection has been considered, and examples exist that show selection for personality traits with both assortative and disassortative mating patterns between personality types. One overlooked aspect of the personality and sexual selection literature is the potential for personality-signaling interactions, specifically with complex signaling. Complex signaling is a diverse topic in itself, and in short, consists of multiple signals within one or more modalities that interact to elicit a receiver response. Research into complex signaling has been thorough, although at times studies discover complex signaling systems that fail to fit into one of the existing hypotheses in the literature. Here, we argue that personalities may interact with complex signaling, which should be considered by researchers of both personality and sexual selection and communication. We describe several ways in which personality-complex signaling interactions could affect both the signaler and receiver, and the way in which they may drive personality-specific signals as well as receiver preferences. Finally, we discuss how considering personality in complex signaling studies may inform theory as well as improve the ability of researchers to accurately describe its function.

scholarly journals Extremely rapid development and early reproduction reduces sexual selection in D. melanogaster populations.

2021 ◽  
Author(s):  
Avani Mital ◽  
Manaswini Sarangi ◽  
Bodhisatta Nandy ◽  
Neha Pandey ◽  
Amitabh Joshi
Keyword(s):  
Sexual Selection ◽  
Sexual Conflict ◽  
Rapid Development ◽  
Fertilization Success ◽  
Direct Selection ◽  
Reproductive Competition ◽  
Short Development Time ◽  
Low Levels ◽  
Selection For

The role of sexual selection in mediating levels of sexual conflict has been demonstrated in a number of experimental evolution studies on Drosophila sp. where the level of competition among males for fertilization success was under direct selection. Here we report that selection for a short development time and early age at reproduction can lead to inadvertent changes in levels of sexual selection in D. melanogaster populations, affecting reproductive competition experienced by males. We demonstrate that faster developing and early reproducing populations showed very low levels of mating in their lifetime (likely being monogamous), low courtship levels, shorter copulation duration and longer maturation time, compared to their ancestral controls. We discuss these results in light of the previously demonstrated reduction of sexual conflict in these populations.

scholarly journals Reproductive Mode and Conflict Shape the Evolution of Male Attributes and Rate of Speciation in the Fish Family Poeciliidae

2021 ◽  
Vol 9 ◽  
Author(s):  
David N. Reznick ◽  
Joseph Travis ◽  
Bart J. A. Pollux ◽  
Andrew I. Furness
Keyword(s):  
Sexual Selection ◽  
Sexual Conflict ◽  
Reproductive Mode ◽  
Fish Family ◽  
Cascading Effects ◽  
The Family ◽  
Maternal Provisioning ◽  
Functional Equivalent ◽  
Selection For

Sexual conflict is caused by differences between the sexes in how fitness is maximized. These differences are shaped by the discrepancy in the investment in gametes, how mates are chosen and how embryos and young are provided for. Fish in the family Poeciliidae vary from completely provisioning eggs before they are fertilized to providing virtually all resources after fertilization via the functional equivalent of a mammalian placenta. This shift in when females provision their young relative to when an egg is fertilized is predicted to cause a fundamental change in when and how sexual conflict is manifested. If eggs are provisioned before fertilization, there should be strong selection for females to choose with whom they mate. Maternal provisioning after fertilization should promote a shift to post-copulatory mate choice. The evolution of maternal provisioning may in turn have cascading effects on the evolution of diverse features of the biology of these fish because of this shift in when mates are chosen. Here we summarize what these consequences are and show that the evolution of maternal provisioning is indeed associated with and appears to govern the evolution of male traits associated with sexual selection. The evolution of placentas and associated conflict does not cause accelerated speciation, contrary to predictions. Accelerated speciation rate is instead correlated with the evolution of male traits associated with sexual selection, which implies a more prominent role of pre-copulatory reproductive isolation in causing speciation in this family.

The role of fecundity and sexual selection in the evolution of size and sexual size dimorphism in New World and Old World voles (Rodentia: Arvicolinae)

Oikos ◽  
2015 ◽  
Vol 125 (9) ◽  
pp. 1250-1260 ◽  
Author(s):  
Vicente García-Navas ◽  
Timothée Bonnet ◽  
Raúl Bonal ◽  
Erik Postma
Keyword(s):  
Sexual Selection ◽  
New World ◽  
Sexual Size Dimorphism ◽  
Old World ◽  
Size Dimorphism

scholarly journals Latitude, elevational climatic zonation and speciation in New World vertebrates

2011 ◽  
Vol 279 (1726) ◽  
pp. 194-201 ◽  
Author(s):  
Carlos Daniel Cadena ◽  
Kenneth H. Kozak ◽  
Juan Pablo Gómez ◽  
Juan Luis Parra ◽  
Christy M. McCain ◽  
...  
Keyword(s):  
New World ◽  
Climatic Variation ◽  
Temperate Zone ◽  
Sister Species ◽  
Tropical Species ◽  
Biodiversity Hotspots ◽  
Tropical Mountains ◽  
Evolutionary Conservatism ◽  
The Tropics

Many biodiversity hotspots are located in montane regions, especially in the tropics. A possible explanation for this pattern is that the narrow thermal tolerances of tropical species and greater climatic stratification of tropical mountains create more opportunities for climate-associated parapatric or allopatric speciation in the tropics relative to the temperate zone. However, it is unclear whether a general relationship exists among latitude, climatic zonation and the ecology of speciation. Recent taxon-specific studies obtained different results regarding the role of climate in speciation in tropical versus temperate areas. Here, we quantify overlap in the climatic distributions of 93 pairs of sister species of mammals, birds, amphibians and reptiles restricted to either the New World tropics or to the Northern temperate zone. We show that elevational ranges of tropical- and temperate-zone species do not differ from one another, yet the temperature range experienced by species in the temperate zone is greater than for those in the tropics. Moreover, tropical sister species tend to exhibit greater similarity in their climatic distributions than temperate sister species. This pattern suggests that evolutionary conservatism in the thermal niches of tropical taxa, coupled with the greater thermal zonation of tropical mountains, may result in increased opportunities for allopatric isolation, speciation and the accumulation of species in tropical montane regions. Our study exemplifies the power of combining phylogenetic and spatial datasets of global climatic variation to explore evolutionary (rather than purely ecological) explanations for the high biodiversity of tropical montane regions.

Scriptural Battlefields: The Old Testament, Legal Culture, and the Polemics of the Spanish New World Empire, 1492–1821

2019 ◽  
Author(s):  
Jorge Cañizares-Esguerra ◽  
Adrian Masters
Keyword(s):  
Old Testament ◽  
Social Order ◽  
New World ◽  
Legal Culture ◽  
Spanish Empire ◽  
Correct Interpretation ◽  
Group Status ◽  
History Of ◽  
New Social Order

Scholars have barely begun to explore the role of the Old Testament in the history of the Spanish New World. And yet this text was central for the Empire’s legal thought, playing a role in its legislation, adjudication, and understandings of group status. Institutions like the Council of the Indies, the Inquisition, and the monarchy itself invited countless parallels to ancient Hebrew justice. Scripture influenced how subjects understood and valued imperial space as well as theories about Paradise or King Solomon’s mines of Ophir. Scripture shaped debates about the nature of the New World past, the legitimacy of the conquest, and the questions of mining, taxation, and other major issues. In the world of privilege and status, conquerors and pessimists could depict the New World and its peoples as the antithesis of Israel and the Israelites, while activists, patriots, and women flipped the script with aplomb. In the readings of Indians, American-born Spaniards, nuns, and others, the correct interpretation of the Old Testament justified a new social order where these groups’ supposed demerits were in reality their virtues. Indeed, vassals and royal officials’ interpretations of the Old Testament are as diverse as the Spanish Empire itself. Scripture even outlasted the Empire. As republicans defeated royalists in the nineteenth century, divergent readings of the book, variously supporting the Israelite monarchy or the Hebrew republic, had their day on the battlefield itself.

scholarly journals Integrating additional knowledge into the estimation of graphical models

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yunqi Bu ◽  
Johannes Lederer
Keyword(s):  
Graphical Models ◽  
Tuning Parameter ◽  
Functional Magnetic Resonance ◽  
Resonance Imaging ◽  
Graphical Modeling ◽  
Standard Methods ◽  
Neighborhood Selection ◽  
Selection For ◽  
The Brain

Abstract Graphical models such as brain connectomes derived from functional magnetic resonance imaging (fMRI) data are considered a prime gateway to understanding network-type processes. We show, however, that standard methods for graphical modeling can fail to provide accurate graph recovery even with optimal tuning and large sample sizes. We attempt to solve this problem by leveraging information that is often readily available in practice but neglected, such as the spatial positions of the measurements. This information is incorporated into the tuning parameter of neighborhood selection, for example, in the form of pairwise distances. Our approach is computationally convenient and efficient, carries a clear Bayesian interpretation, and improves standard methods in terms of statistical stability. Applied to data about Alzheimer’s disease, our approach allows us to highlight the central role of lobes in the connectivity structure of the brain and to identify an increased connectivity within the cerebellum for Alzheimer’s patients compared to other subjects.

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