OPPOSING NATURAL SELECTION FROM HERBIVORES AND PATHOGENS MAY MAINTAIN FLORAL-COLOR VARIATION IN CLAYTONIA VIRGINICA (PORTULACACEAE)

Evolution ◽  
2004 ◽  
Vol 58 (11) ◽  
pp. 2426 ◽  
Author(s):  
Frank M. Frey
Keyword(s):  
Natural Selection ◽  
Color Variation ◽  
Floral Color ◽  
Claytonia Virginica

scholarly journals Comparative Transcriptomics Provides Insight into Floral Color Polymorphism in a Pleione limprichtii Orchid Population

2019 ◽  
Vol 21 (1) ◽  
pp. 247 ◽  
Author(s):  
Yiyi Zhang ◽  
Tinghong Zhou ◽  
Zhongwu Dai ◽  
Xiaoyu Dai ◽  
Wei Li ◽  
...  
Keyword(s):  
Distribution Pattern ◽  
Expression Patterns ◽  
Color Polymorphism ◽  
Color Variation ◽  
Similar Species ◽  
Color Formation ◽  
Floral Color ◽  
Species Evolution ◽  
Different Color ◽  
Insight Into

Floral color polymorphism can provide great insight into species evolution from a genetic and ecological standpoint. Color variations between species are often mediated by pollinators and are fixed characteristics, indicating their relevance to adaptive evolution, especially between plants within a single population or between similar species. The orchid genus Pleione has a wide variety of flower colors, from violet, rose-purple, pink, to white, but their color formation and its evolutionary mechanism are unclear. Here, we selected the P. limprichtii population in Huanglong, Sichuan Province, China, which displayed three color variations: Rose-purple, pink, and white, providing ideal material for exploring color variations with regard to species evolution. We investigated the distribution pattern of the different color morphs. The ratio of rose-purple:pink:white-flowered individuals was close to 6:3:1. We inferred that the distribution pattern may serve as a reproductive strategy to maintain the population size. Metabolome analysis was used to reveal that cyanindin derivatives and delphidin are the main color pigments involved. RNA sequencing was used to characterize anthocyanin biosynthetic pathway-related genes and reveal different color formation pathways and transcription factors in order to identify differentially-expressed genes and explore their relationship with color formation. In addition, qRT-PCR was used to validate the expression patterns of some of the genes. The results show that PlFLS serves as a crucial gene that contributes to white color formation and that PlANS and PlUFGT are related to the accumulation of anthocyanin which is responsible for color intensity, especially in pigmented flowers. Phylogenetic and co-expression analyses also identified a R2R3-MYB gene PlMYB10, which is predicted to combine with PlbHLH20 or PlbHLH26 along with PlWD40-1 to form an MBW protein complex (MYB, bHLH, and WDR) that regulates PlFLS expression and may serve as a repressor of anthocyanin accumulation-controlled color variations. Our results not only explain the molecular mechanism of color variation in P. limprichtii, but also contribute to the exploration of a flower color evolutionary model in Pleione, as well as other flowering plants.

scholarly journals Color Variation and Natural Selection in Italian Sparrows

1972 ◽  
Vol 39 (3) ◽  
pp. 351-362 ◽  
Author(s):  
Richard F. Johnston
Keyword(s):  
Natural Selection ◽  
Color Variation

scholarly journals Floral Color Variation in Drosera cistiflora Is Associated With Switches in Beetle Pollinator Assemblages

2020 ◽  
Vol 11 ◽  
Author(s):  
Steven D. Johnson ◽  
Caitlin G. von Witt ◽  
Bruce Anderson
Keyword(s):  
Color Variation ◽  
Floral Color

Floral color variation and associations with fitness-related traits in Malva moschata (Malvaceae)

2011 ◽  
Vol 26 (3) ◽  
pp. 235-243 ◽  
Author(s):  
FRANK M. FREY ◽  
JESSICA DUNTON ◽  
KAILEY GARLAND
Keyword(s):  
Color Variation ◽  
Floral Color

scholarly journals Local adaptation and sexual selection drive intra-island diversification in a songbird lineage: differential divergence in autosomes and sex chromosomes

2018 ◽  
Author(s):  
Yann XC Bourgeois ◽  
Joris AM Bertrand ◽  
Boris Delahaie ◽  
Hélène Holota ◽  
Christophe Thébaud ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Natural Selection ◽  
Reproductive Isolation ◽  
Local Adaptation ◽  
Sex Chromosomes ◽  
Genomic Variation ◽  
Color Variation ◽  
Mating Signals ◽  
Genome Wide

AbstractRecently diverged taxa showing marked phenotypic and ecological diversity are optimal systems to test the relative importance of two major evolutionary mechanisms, adaptation to local ecological conditions by natural selection, or mechanisms of reproductive isolation such as assortative mating mediated by sexually selected mating signals or post-zygotic incompatibilities. Whereas local adaptation is expected to affect many loci throughout the genome, traits acting as mating signals are expected to be located on sex chromosomes and have a simple genetic basis. We used genome-wide markers to test these predictions in Reunion Island’s gray-white eye (Zosterops borbonicus), which has recently diversified into five distinct plumage forms. Two of them correspond to a polymorphic highland population that is separated by a steep ecological gradient from three distinct lowland forms that show narrow contact zones in plumage color traits, yet no association with environmental variables. An analysis of population structure using genome-wide SNP loci revealed two major clades corresponding to highland and lowland forms, respectively, with the latter separated further into three independent lineages corresponding to plumage forms. Coalescent tests of alternative demographic scenarios provided support for divergence of highland and lowland lineages with an intensification of gene flow in the last 60,000 years. Landscapes of genomic variation revealed that signatures of selection associated with elevation are found at multiple regions across the genome, whereas most loci associated with the lowland forms are located on the Z sex chromosome. A gene ontology analysis identified TYRP1, a Z-linked color gene, as a likely candidate locus underlying color variation among lowland forms. Our results are consistent with the role of natural selection in driving the divergence of locally adapted highland populations, and the role of sexual selection in differentiating lowland forms through reproductive isolation mechanisms, showing that both modes of lineage divergence can take place at very small geographic scales in birds.

Intraspecific floral color variation as perceived by pollinators and non-pollinators: evidence for pollinator-imposed constraints?

2019 ◽  
Vol 33 (4) ◽  
pp. 461-479 ◽  
Author(s):  
Kellen C. Paine ◽  
Thomas E. White ◽  
Kenneth D. Whitney
Keyword(s):  
Color Variation ◽  
Floral Color

scholarly journals Dissecting dynamics and differences of selective pressures in the evolution of human pigmentation

2018 ◽  
Author(s):  
Xin Huang ◽  
Yungang He ◽  
Sijia Wang ◽  
Li Jin
Keyword(s):  
Natural Selection ◽  
Ultraviolet Radiation ◽  
Complex Traits ◽  
Complex Trait ◽  
Color Variation ◽  
Human Populations ◽  
Selective Pressures ◽  
Multiple Genes ◽  
Dark Pigmentation ◽  
Time Periods

AbstractHuman pigmentation is a highly diverse and complex trait among populations, and has drawn particular attention from both academic and non-academic investigators for thousands of years. Previous studies detected selection signals in several human pigmentation genes, but few studies have integrated contribution from multiple genes to the evolution of human pigmentation. Moreover, none has quantified selective pressures on human pigmentation over epochs and between populations. Here, we dissect dynamics and differences of selective pressures during different periods and between distinct populations with new approaches. We propose a new model with multiple populations to estimate historical selective pressures by summarizing selective pressures on multiple genes. We use genotype data of 19 genes associated with human pigmentation from 17 datasets, and obtain data for 2346 individuals of six representative population groups from worldwide. Our results quantify selective pressures on light pigmentation not only in modern Europeans (0.0249/generation) but also in proto-Eurasians (0.00665/generation). Our results also support several derived alleles associated with human dark pigmentation may under directional selection by quantifying differences of selective pressures between populations. Our study provides a first attempt to quantitatively investigate the dynamics of selective pressures during different time periods in the evolution of human pigmentation, and may facilitate studies of the evolution of other complex traits.Author SummaryThe color variation of human skin, hair, and eye is affected by multiple genes with different roles. This diversity may be shaped by natural selection and adapted for ultraviolet radiation in different environments around the world. As human populations migrated out from Africa, the ultraviolet radiation in the environment they encountered also changed. It is possible that the selective pressures on human pigmentation varied throughout human evolutionary history. In this study, we develop a new approach and estimate historical selective pressures on light pigmentation not only in modern Europeans but also in proto-Eurasians. To our best knowledge, this is the first study that quantifies selective pressures during different time periods in the evolution of human pigmentation. Besides, we provide statistical evidence to support several genes associated with human dark pigmentation may be favored by natural selection. Thus, natural selection may not only affect light pigmentation in Eurasians, but also influence dark pigmentation in Africans.

Natural selection and "sudden death."

1979 ◽  
Vol 34 (3) ◽  
pp. 274-275
Author(s):  
David Chiszar ◽  
Karlana Carpen
Keyword(s):  
Natural Selection ◽  
Sudden Death
Sign in / Sign up

Export Citation Format

Share Document