scholarly journals Evolution of correlated complexity in the radically different courtship signals of birds-of-paradise

2018 ◽  
Author(s):  
Russell A. Ligon ◽  
Christopher D. Diaz ◽  
Janelle L. Morano ◽  
Jolyon Troscianko ◽  
Martin Stevens ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Evolutionary Biology ◽  
Evolutionary Dynamics ◽  
Functional Integration ◽  
Empirical Support ◽  
Evolutionary Patterns ◽  
Evolutionary Innovation ◽  
Birds Of Paradise ◽  
Analytical Approaches

Ornaments used in courtship often vary wildly among species, reflecting the evolutionary interplay between mate preference functions and the constraints imposed by natural selection. Consequently, understanding the evolutionary dynamics responsible for ornament diversification has been a longstanding challenge in evolutionary biology. However, comparing radically different ornaments across species, as well as different classes of ornaments within species, is a profound challenge to understanding diversification of sexual signals. Using novel methods and a unique natural history dataset, we explore evolutionary patterns of ornament evolution in a group - the birds-of-paradise - exhibiting dramatic phenotypic diversification widely assumed to be driven by sexual selection. Rather than the tradeoff between ornament types originally envisioned by Darwin and Wallace, we found positive correlations among cross-modal (visual/acoustic) signals indicating functional integration of ornamental traits into a composite unit - the courtship phenotype. Furthermore, given the broad theoretical and empirical support for the idea that systemic robustness - functional overlap and interdependency - promotes evolutionary innovation, we posit that birds-of-paradise have radiated extensively through ornamental phenotype space as a consequence of the robustness in the courtship phenotype that we document at a phylogenetic scale. We suggest that the degree of robustness in courtship phenotypes among taxa can provide new insights into the relative influence of sexual and natural selection on phenotypic radiations.Author SummaryAnimals frequently vary widely in ornamentation, even among closely related species. Understanding the patterns that underlie this variation is a significant challenge, requiring comparisons among drastically different traits - like comparing apples to oranges. Here, we use novel analytical approaches to quantify variation in ornamental diversity and richness across the wildly divergent birds-of-paradise, a textbook example of how sexual selection can profoundly shape organismal phenotypes. We find that color and acoustic complexity, along with behavior and acoustic complexity, are positively correlated across evolutionary time-scales. Positive covariation among ornament classes suggests that selection is acting on correlated suites of traits - a composite courtship phenotype - and that this integration may be partially responsible for the extreme variation we see in birds-of-paradise.

scholarly journals Phenotype bias determines how RNA structures occupy the morphospace of all possible shapes

2020 ◽  
Author(s):  
Kamaludin Dingle ◽  
Fatme Ghaddar ◽  
Petr Šulc ◽  
Ard A. Louis
Keyword(s):  
Natural Selection ◽  
Rna Secondary Structure ◽  
Evolutionary Biology ◽  
Evolutionary Dynamics ◽  
Coarse Grained ◽  
Rna Structures ◽  
Non Coding Rna ◽  
Ultimate Cause ◽  
Uniform Random Sampling ◽  
Bias Versus

The relative prominence of developmental bias versus natural selection is a long standing controversy in evolutionary biology. Here we demonstrate quantitatively that developmental bias is the primary explanation for the occupation of the morphospace of RNA secondary structure (SS) shapes. By using the RNAshapes method to define coarse-grained SS classes, we can directly measure the frequencies that non-coding RNA SS shapes appear in nature. Our main findings are, firstly, that only the most frequent structures appear in nature: The vast majority of possible structures in the morphospace have not yet been explored. Secondly, and perhaps more surprisingly, these frequencies are accurately predicted by the likelihood that structures appear upon uniform random sampling of sequences. The ultimate cause of these patterns is not natural selection, but rather strong phenotype bias in the RNA genotype-phenotype (GP) map, a type of developmental bias that tightly constrains evolutionary dynamics to only act within a reduced subset of structures which are easy to “find”.

scholarly journals PRDM9 Diversity at Fine Geographical Scale Reveals Contrasting Evolutionary Patterns and Functional Constraints in Natural Populations of House Mice

2019 ◽  
Vol 36 (8) ◽  
pp. 1686-1700 ◽  
Author(s):  
Covadonga Vara ◽  
Laia Capilla ◽  
Luca Ferretti ◽  
Alice Ledda ◽  
Rosa A Sánchez-Guillén ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Evolutionary Biology ◽  
Evolutionary Dynamics ◽  
Rapid Evolution ◽  
Natural Populations ◽  
Global Scale ◽  
House Mice ◽  
Functional Constraints ◽  
Evolutionary Patterns ◽  
Data Set

Abstract One of the major challenges in evolutionary biology is the identification of the genetic basis of postzygotic reproductive isolation. Given its pivotal role in this process, here we explore the drivers that may account for the evolutionary dynamics of the PRDM9 gene between continental and island systems of chromosomal variation in house mice. Using a data set of nearly 400 wild-caught mice of Robertsonian systems, we identify the extent of PRDM9 diversity in natural house mouse populations, determine the phylogeography of PRDM9 at a local and global scale based on a new measure of pairwise genetic divergence, and analyze selective constraints. We find 57 newly described PRDM9 variants, this diversity being especially high on Madeira Island, a result that is contrary to the expectations of reduced variation for island populations. Our analysis suggest that the PRDM9 allelic variability observed in Madeira mice might be influenced by the presence of distinct chromosomal fusions resulting from a complex pattern of introgression or multiple colonization events onto the island. Importantly, we detect a significant reduction in the proportion of PRDM9 heterozygotes in Robertsonian mice, which showed a high degree of similarity in the amino acids responsible for protein–DNA binding. Our results suggest that despite the rapid evolution of PRDM9 and the variability detected in natural populations, functional constraints could facilitate the accumulation of allelic combinations that maintain recombination hotspot symmetry. We anticipate that our study will provide the basis for examining the role of different PRDM9 genetic backgrounds in reproductive isolation in natural populations.

scholarly journals Stronger net selection on males across animals

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Lennart Winkler ◽  
Maria Moiron ◽  
Edward H Morrow ◽  
Tim Janicke
Keyword(s):  
Sex Differences ◽  
Sexual Selection ◽  
Natural Selection ◽  
Environmental Change ◽  
Evolutionary Dynamics ◽  
Comparative Approach ◽  
Sex Bias ◽  
Adaptive Potential ◽  
Stressful Environment ◽  
Preliminary Support

Sexual selection is considered the major driver for the evolution of sex differences. However, the eco-evolutionary dynamics of sexual selection and their role for a population’s adaptive potential to respond to environmental change have only recently been explored. Theory predicts that sexual selection promotes adaptation at a low demographic cost only if sexual selection is aligned with natural selection and if net selection is stronger on males compared to females. We used a comparative approach to show that net selection is indeed stronger in males and provide preliminary support that this sex bias is associated with sexual selection. Given that both sexes share the vast majority of their genes, our findings corroborate the notion that the genome is often confronted with a more stressful environment when expressed in males. Collectively, our study supports one of the long-standing key assumptions required for sexual selection to bolster adaptation, and sexual selection may therefore enable some species to track environmental change more efficiently.

scholarly journals Ecological opportunity and the rise and fall of crocodylomorph evolutionary innovation

2021 ◽  
Vol 288 (1947) ◽  
Author(s):  
Thomas L. Stubbs ◽  
Stephanie E. Pierce ◽  
Armin Elsler ◽  
Philip S. L. Anderson ◽  
Emily J. Rayfield ◽  
...  
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Evolutionary Dynamics ◽  
Evolutionary Rates ◽  
Apex Predators ◽  
Ecological Opportunity ◽  
Evolutionary Innovation ◽  
Great Heterogeneity ◽  
Living Species

Understanding the origin, expansion and loss of biodiversity is fundamental to evolutionary biology. The approximately 26 living species of crocodylomorphs (crocodiles, caimans, alligators and gharials) represent just a snapshot of the group's rich 230-million-year history, whereas the fossil record reveals a hidden past of great diversity and innovation, including ocean and land-dwelling forms, herbivores, omnivores and apex predators. In this macroevolutionary study of skull and jaw shape disparity, we show that crocodylomorph ecomorphological variation peaked in the Cretaceous, before declining in the Cenozoic, and the rise and fall of disparity was associated with great heterogeneity in evolutionary rates. Taxonomically diverse and ecologically divergent Mesozoic crocodylomorphs, like marine thalattosuchians and terrestrial notosuchians, rapidly evolved novel skull and jaw morphologies to fill specialized adaptive zones. Disparity in semi-aquatic predatory crocodylians, the only living crocodylomorph representatives, accumulated steadily, and they evolved more slowly for most of the last 80 million years, but despite their conservatism there is no evidence for long-term evolutionary stagnation. These complex evolutionary dynamics reflect ecological opportunities, that were readily exploited by some Mesozoic crocodylomorphs but more limited in Cenozoic crocodylians.

scholarly journals General Models of Multilocus Evolution

Genetics ◽  
2002 ◽  
Vol 161 (4) ◽  
pp. 1727-1750 ◽  
Author(s):  
Mark Kirkpatrick ◽  
Toby Johnson ◽  
Nick Barton
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Evolutionary Dynamics ◽  
Linkage Equilibrium ◽  
Sex Linkage ◽  
Genetic Composition ◽  
Evolutionary Forces ◽  
And Migration ◽  
The Web ◽  
Quasi Linkage Equilibrium

Abstract In 1991, Barton and Turelli developed recursions to describe the evolution of multilocus systems under arbitrary forms of selection. This article generalizes their approach to allow for arbitrary modes of inheritance, including diploidy, polyploidy, sex linkage, cytoplasmic inheritance, and genomic imprinting. The framework is also extended to allow for other deterministic evolutionary forces, including migration and mutation. Exact recursions that fully describe the state of the population are presented; these are implemented in a computer algebra package (available on the Web at http://helios.bto.ed.ac.uk/evolgen). Despite the generality of our framework, it can describe evolutionary dynamics exactly by just two equations. These recursions can be further simplified using a “quasi-linkage equilibrium” (QLE) approximation. We illustrate the methods by finding the effect of natural selection, sexual selection, mutation, and migration on the genetic composition of a population.

scholarly journals Sexual selection and the evolutionary dynamics of the major histocompatibility complex

2014 ◽  
Vol 281 (1796) ◽  
pp. 20141662 ◽  
Author(s):  
Maciej Jan Ejsmond ◽  
Jacek Radwan ◽  
Anthony B. Wilson
Keyword(s):  
Sexual Selection ◽  
Major Histocompatibility Complex ◽  
Natural Selection ◽  
Evolutionary Dynamics ◽  
Allelic Variation ◽  
Allelic Diversity ◽  
Major Histocompatibility ◽  
Disassortative Mating ◽  
Functional Variants ◽  
Histocompatibility Complex

The genes of the major histocompatibility complex (MHC) are a key component of the adaptive immune system and among the most variable loci in the vertebrate genome. Pathogen-mediated natural selection and MHC-based disassortative mating are both thought to structure MHC polymorphism, but their effects have proven difficult to discriminate in natural systems. Using the first model of MHC dynamics incorporating both survival and reproduction, we demonstrate that natural and sexual selection produce distinctive signatures of MHC allelic diversity with critical implications for understanding host–pathogen dynamics. While natural selection produces the Red Queen dynamics characteristic of host–parasite interactions, disassortative mating stabilizes allele frequencies, damping major fluctuations in dominant alleles and protecting functional variants against drift. This subtle difference generates a complex interaction between MHC allelic diversity and population size. In small populations, the stabilizing effects of sexual selection moderate the effects of drift, whereas pathogen-mediated selection accelerates the loss of functionally important genetic diversity. Natural selection enhances MHC allelic variation in larger populations, with the highest levels of diversity generated by the combined action of pathogen-mediated selection and disassortative mating. MHC-based sexual selection may help to explain how functionally important genetic variation can be maintained in populations of conservation concern.

Allometric scaling in two bushcricket species (Orthoptera: Tettigoniidae) suggests sexual selection on song-generating structures

2020 ◽  
Vol 131 (3) ◽  
pp. 521-535
Author(s):  
Fran Rebrina ◽  
Marianna Anichini ◽  
Klaus Reinhold ◽  
Gerlind U C Lehmann
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Allometric Scaling ◽  
Functional Integration ◽  
Stabilizing Selection ◽  
Evolutionary Patterns ◽  
Selection For ◽  
Stridulatory Apparatus ◽  
Mirror Area ◽  
The Right

Abstract In acoustically communicating bushcrickets (Orthoptera: Tettigoniidae), most signal properties are influenced by the dimensions of the stridulatory apparatus, which in turn reflects body size and condition of the signaller. Females can assess male quality based on acoustic signals, suggesting that male stridulatory structures may be under sexual selection. We investigated scaling relationships between stridulatory structures, body size and body mass in males of the bushcricket Poecilimon veluchianus veluchianus, in comparison to the congeneric Poecilimon ampliatus. Stridulatory structures in P. v. veluchianus exhibited strong left–right correlation and coupling with body size and mass, indicating stabilizing selection for functional integration. In addition, sound-generating (the width of stridulatory teeth) and sound-radiating (mirror area on the right tegmen) structures scaled hyperallometrically to tegmen area, suggesting that both are under sexual selection. Finally, interspecies comparison revealed a steeper slope in tegmen area and stridulatory file length in relation to body size in P. ampliatus than in P. v. veluchianus, implying stronger sexual selection in the former, smaller species. Our study emphasizes the significance of a comparative allometric approach in elucidating evolutionary patterns of sound-generating and -radiating structures.

Sex, Difference, and Desire

2020 ◽  
pp. 177-232
Author(s):  
Ben Bradley
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Evolutionary Psychology ◽  
Evolutionary Biology ◽  
Racial Politics ◽  
Sexual Agency ◽  
Human History ◽  
Male And Female ◽  
Males And Females ◽  
Descent Of Man

The parts of The Descent of Man dealing with sexual desire and difference have sparked more controversy and misrepresentation than any of Darwin’s other publications. Crucial to Descent’s arguments is the derivation of sexual selection from the dramas of display and desire observed among animals. The book describes four plotlines structuring the theatre of sexual agency in animals, each having different implications for the roles played by males and females. When Descent extends these plotlines to humans, they alter and modulate into an even more varied array of scenarios, again, each with its own distinctive roles for women and men. A mirror-dynamic figures centrally in both animal and human sex—the need to recognize or predict others’ desires so as to act in a way to arouse them. However, several nodes of concern disturb Darwin’s presentation of human sex: tensions between his three epochs of human history; Victorian racial politics; Victorian ideas about male and female superiority; and the imperatives of propriety. The chapter illustrates some of the muddles that result from these concerns, including: confirmation bias; aporia in argument; grammatical kinks; and overlap between sexual and natural selection. Finally, the chapter instances some of the main resonances in more recent scholarship of Darwin’s discussion of sex, instancing debates in feminism, about anthropomorphism, in evolutionary biology, and evolutionary psychology.

scholarly journals Evolutionary biology of language

2000 ◽  
Vol 355 (1403) ◽  
pp. 1615-1622 ◽  
Author(s):  
Martin A. Nowak
Keyword(s):  
Game Theory ◽  
Natural Selection ◽  
Mathematical Models ◽  
Evolutionary Biology ◽  
Evolutionary Dynamics ◽  
Animal Communication ◽  
Language Evolution ◽  
Human Language ◽  
Exchange Information ◽  
New Ideas

Language is the most important evolutionary invention of the last few million years. It was an adaptation that helped our species to exchange information, make plans, express new ideas and totally change the appearance of the planet. How human language evolved from animal communication is one of the most challenging questions for evolutionary biology. The aim of this paper is to outline the major principles that guided language evolution in terms of mathematical models of evolutionary dynamics and game theory. I will discuss how natural selection can lead to the emergence of arbitrary signs, the formation of words and syntactic communication.

scholarly journals Morphological Evolution: Bioinspired Methods for Analyzing Bioinspired Robots

2022 ◽  
Vol 8 ◽  
Author(s):  
Eric Aaron ◽  
Joshua Hawthorne-Madell ◽  
Ken Livingston ◽  
John H. Long
Keyword(s):  
Evolutionary Biology ◽  
Morphological Traits ◽  
Evolutionary Dynamics ◽  
Morphological Evolution ◽  
Analytical Techniques ◽  
Genetic Mutation ◽  
Evolutionary Mechanisms ◽  
Selection Gradient ◽  
Common Interests ◽  
Analytical Approaches

To fully understand the evolution of complex morphologies, analyses cannot stop at selection: It is essential to investigate the roles and interactions of multiple processes that drive evolutionary outcomes. The challenges of undertaking such analyses have affected both evolutionary biologists and evolutionary roboticists, with their common interests in complex morphologies. In this paper, we present analytical techniques from evolutionary biology, selection gradient analysis and morphospace walks, and we demonstrate their applicability to robot morphologies in analyses of three evolutionary mechanisms: randomness (genetic mutation), development (an explicitly implemented genotype-to-phenotype map), and selection. In particular, we applied these analytical techniques to evolved populations of simulated biorobots—embodied robots designed specifically as models of biological systems, for the testing of biological hypotheses—and we present a variety of results, including analyses that do all of the following: illuminate different evolutionary dynamics for different classes of morphological traits; illustrate how the traits targeted by selection can vary based on the likelihood of random genetic mutation; demonstrate that selection on two selected sets of morphological traits only partially explains the variance in fitness in our biorobots; and suggest that biases in developmental processes could partially explain evolutionary dynamics of morphology. When combined, the complementary analytical approaches discussed in this paper can enable insight into evolutionary processes beyond selection and thereby deepen our understanding of the evolution of robotic morphologies.

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