Selection for independence of floral and vegetative traits: evidence from correlation patterns in five species

1996 ◽  
Vol 74 (4) ◽  
pp. 642-644 ◽  
Author(s):  
Jeffrey K. Conner ◽  
Andrea Sterling
Keyword(s):  
Natural Selection ◽  
Plant Traits ◽  
Genetic Relationships ◽  
Functional Independence ◽  
Floral Traits ◽  
Evolutionary Time ◽  
Vegetative Traits ◽  
Selection For ◽  
Positive Correlations ◽  
Trait Groups

Underlying developmental and genetic relationships cause positive correlations among the sizes of a variety of plant traits. Selection for functional independence among traits, however, can reduce these correlations over evolutionary time. In 1960, R.L. Berg hypothesized that the sizes of flowers in insect-pollinated plants should be selected to remain constant regardless of the size of vegetative structures, so that flowers match the sizes of their pollinators for effective pollination. This hypothesis of functional independence of floral sizes from the size of the rest of the plant predicts that correlations between floral and vegetative traits should be reduced relative to correlations within trait groups. We measured correlations in five species of insect-pollinated plants, including four Brassicaceae and Phlox divaricata. Our results support the hypothesis. The correlations among floral traits and the correlations among vegetative traits were significantly greater than the correlations across these two groups of traits in all five species. Keywords: phenotypic correlations, natural selection, functional independence, pollination, floral evolution.

scholarly journals Patterns of phenotypic correlations among morphological traits across plants and animals

2014 ◽  
Vol 369 (1649) ◽  
pp. 20130246 ◽  
Author(s):  
Jeffrey K. Conner ◽  
Idelle A. Cooper ◽  
Raffica J. La Rosa ◽  
Samuel G. Pérez ◽  
Anne M. Royer
Keyword(s):  
Functional Independence ◽  
Floral Traits ◽  
Linear Measurements ◽  
Environmental Variance ◽  
Phenotypic Correlations ◽  
Vegetative Traits ◽  
Highly Correlated ◽  
Complete Metamorphosis ◽  
Trait Groups

Despite the long-standing interest of biologists in patterns of correlation and phenotypic integration, little attention has been paid to patterns of correlation across a broad phylogenetic spectrum. We report analyses of mean phenotypic correlations among a variety of linear measurements from a wide diversity of plants and animals, addressing questions about function, development, integration and modularity. These analyses suggest that vertebrates, hemimetabolous insects and vegetative traits in plants have similar mean correlations, around 0.5. Traits of holometabolous insects are much more highly correlated, with a mean correlation of 0.84; this may be due to developmental homeostasis caused by lower spatial and temporal environmental variance during complete metamorphosis. The lowest mean correlations were those between floral and vegetative traits, consistent with Berg's ideas about functional independence between these modules. Within trait groups, the lowest mean correlations were among vertebrate head traits and floral traits (0.38–0.39). The former may be due to independence between skull modules. While there is little evidence for floral integration overall, certain sets of functionally related floral traits are highly integrated. A case study of the latter is described from wild radish flowers.

Correlated effects of selection for flower size in Raphanus raphanistrum

2007 ◽  
Vol 85 (2) ◽  
pp. 160-166 ◽  
Author(s):  
Kari Lehtilä ◽  
Kristina Holmén Bränn
Keyword(s):  
Plant Traits ◽  
Plant Size ◽  
Flower Size ◽  
Flowering Plant ◽  
Realized Heritability ◽  
Raphanus Raphanistrum ◽  
Trade Offs ◽  
Vegetative Traits ◽  
Two Generations ◽  
Selection For

The evolution of flower size may be constrained by trade-offs between flower size and other plant traits. The aim of this study was to determine how selection on flower size affects both reproductive and vegetative traits. Raphanus raphanistrum L. was used as the study species. Artificial selection for small and large petal size was carried out for two generations. We measured the realized heritability of flower size and recorded flower production, time to flowering, plant size, and seed production in the two selection lines. The realized heritability was h2 = 0.49. Our study, therefore, showed that R. raphanistrum has potential for rapid evolutionary change of floral size. The lines with large flowers produced smaller seeds and started to flower later than the lines with small flowers. There was no trade-off between flower size and flower number, but the lines selected for large flower size had more flowers and a larger plant size than lines selected for small flowers. Estimates of restricted maximum likelihood (REML) analysis of pedigrees also showed that flower size had a positive genetic correlation with start of flowering and plant height.

scholarly journals Natural selection on floral morphology can be influenced by climate

2015 ◽  
Vol 282 (1808) ◽  
pp. 20150178 ◽  
Author(s):  
Diane R. Campbell ◽  
John M. Powers
Keyword(s):  
Natural Selection ◽  
Water Resources ◽  
Temporal Variation ◽  
Rocky Mountains ◽  
Floral Morphology ◽  
Floral Traits ◽  
Selective Agent ◽  
Pollination Success ◽  
Selection For ◽  
Colorado Rocky Mountains

Climate has the potential to influence evolution, but how it influences the strength or direction of natural selection is largely unknown. We quantified the strength of selection on four floral traits of the subalpine herb Ipomopsis sp. in 10 years that differed in precipitation, causing extreme temporal variation in the date of snowmelt in the Colorado Rocky Mountains. The chosen floral traits were under selection by hummingbird and hawkmoth pollinators, with hawkmoth abundance highly variable across years. Selection for flower length showed environmental sensitivity, with stronger selection in years with later snowmelt, as higher water resources can allow translation of pollination success into fitness based on seed production. Selection on corolla width also varied across years, favouring narrower corolla tubes in two unusual years with hawkmoths, and wider corollas in another late snowmelt year. Our results illustrate how changes in climate could alter natural selection even when the primary selective agent is not directly influenced.

Morph-specific correlations between floral traits in a distylous Ophiorrhiza napoensis (Rubiaceae) population in southern China

2001 ◽  
Vol 17 (5) ◽  
pp. 719-728 ◽  
Author(s):  
HIROSHI KUDOH ◽  
TAKASHI SUGAWARA ◽  
SUGONG WU ◽  
JIN MURATA
Keyword(s):  
Southern China ◽  
Principal Component ◽  
Corolla Tube ◽  
Floral Traits ◽  
Evergreen Forest ◽  
Tube Length ◽  
Multiple Traits ◽  
Floral Trait ◽  
Subtropical Evergreen Forest ◽  
Positive Correlations

Floral trait correlations were compared between the two flower morphs of a distylous Ophiorrhiza napoensis population in a subtropical evergreen forest at the Defu Natural Animal Preserve, Guangxi, China. Common principal component analyses indicated that overall patterns in correlations among floral traits were morph specific in the study population. Strong positive correlations (r > 0.9) between anther height and corolla-tube length were found in both morphs. Stigma height correlated positively with corolla-tube length in the long-styled morph (r = 0.843), but not in the short-styled morph (r = −0.018). Flower-morph-specific correlation suggests that natural selection by pollinators has moulded trait covariance among floral traits. Because morph-specific correlations are expressed as the patterns of within-morph variation among multiple traits, putative genes responsible for the stigma-corolla tube correlation should not link to the supergene for sex-organ reciprocity between the morphs, but their expression is limited in the long-styled morph.

Composite trait selection to improve reproduction and ewe productivity: a review

2009 ◽  
Vol 49 (1) ◽  
pp. 9 ◽  
Author(s):  
G. D. Snowder ◽  
N. M. Fogarty
Keyword(s):  
Individual Component ◽  
Genetic Relationships ◽  
Reproductive Efficiency ◽  
Component Trait ◽  
Litter Weight ◽  
Growth Selection ◽  
Component Traits ◽  
Selection For ◽  
Genetic Responses ◽  
Lamb Growth

Reproduction and ewe productivity are complex composite traits that are influenced by several component traits. Genetic improvement by selection for an individual component trait may not always be advantageous because adverse or neutral genetic relationships can exist among the component traits. Selection for an overall composite trait of ewe productivity, defined as litter weight weaned per ewe joined, can result in a balanced biological composite trait with favourable responses in component traits including fertility, number of lambs born, lamb survival, lactation and lamb growth. Selection for litter weight weaned may also overcome adverse genetic relationships among reproductive component traits. This review examines the genetic responses of selecting directly for litter weight weaned, compared with selection responses for one or more of its component traits. It is concluded that selection to improve reproductive efficiency and ewe productivity, under most production and environmental systems, would benefit from selection for a composite trait such as litter weight weaned, rather than for a single component trait.

The relationship between facial whorl direction and sidedness in ridden horses

2006 ◽  
Vol 35 ◽  
pp. 247-250
Author(s):  
H. Randle ◽  
E. Elworthy
Keyword(s):  
Natural Selection ◽  
Artificial Selection ◽  
Competitive Ability ◽  
Close Association ◽  
Human Behaviour ◽  
Physical Ability ◽  
Facial Hair ◽  
Selection For ◽  
The Relationship ◽  
The Brain

The influence of Natural Selection on the evolution of the horse (Equus callabus) is minimal due to its close association with humans. Instead Artificial Selection is commonly imposed through selection for features such as a ‘breed standard’ or competitive ability. It has long been considered to be useful if indicators of characteristics such as physical ability could be identified. Kidd (1902) suggested that the hair coverings of animals were closely related to their lifestyle, whether they were active or passive. In 1973 Smith and Gong concluded that hair whorl (trichloglyph) pattern and human behaviour is linked since hair patterning is determined at the same time as the brain develops in the foetus. More recently Grandin et al. (1995), Randle (1998) and Lanier et al. (2001) linked features of facial hair whorls to behaviour and production in cattle. Hair whorl features have also been related to temperament in equines (Randle et al., 2003).

scholarly journals Induced defenses alter the strength and direction of natural selection on reproductive traits in common milkweed

2016 ◽  
Author(s):  
Ken A. Thompson ◽  
Kaitlin A. Cory ◽  
Marc T. J. Johnson
Keyword(s):  
Natural Selection ◽  
Jasmonic Acid ◽  
Reproductive Traits ◽  
Induced Defenses ◽  
Asclepias Syriaca ◽  
Ecological Processes ◽  
Foliar Damage ◽  
Antiherbivore Defenses ◽  
Selection For ◽  
Generate Plant

AbstractEvolutionary biologists have long sought to understand the ecological processes that generate plant reproductive diversity. Recent evidence indicates that constitutive antiherbivore defenses can alter natural selection on reproductive traits, but it is unclear whether induced defenses will have the same effect and whether reduced foliar damage in defended plants is the cause of this pattern. In a factorial field experiment using common milkweed, Asclepias syriaca, we induced plant defenses using jasmonic acid (JA) and imposed foliar damage using scissors. We found that JA-induced plants experienced selection for more inflorescences that were smaller in size (fewer flowers), while control plants only experienced a trend toward selection for larger inflorescences (more flowers); all effects were independent of foliar damage. Our results demonstrate that induced defenses can alter both the strength and direction of selection on reproductive traits, and suggest that antiherbivore defenses may promote the evolution of plant reproductive diversity.

scholarly journals A SIMULATION STUDY OF TRUNCATION SELECTION FOR A QUANTITATIVE TRAIT OPPOSED BY NATURAL SELECTION

Genetics ◽  
1980 ◽  
Vol 94 (4) ◽  
pp. 989-1000
Author(s):  
Francis Minvielle
Keyword(s):  
Natural Selection ◽  
Artificial Selection ◽  
Random Mating ◽  
Selection Response ◽  
Quantitative Character ◽  
Mass Selection ◽  
Frequency Selection ◽  
Selection Experiments ◽  
Selection For ◽  
Selective Process

ABSTRACT A quantitative character controlled at one locus with two alleles was submitted to artificial (mass) selection and to three modes of opposing natural selection (directional selection, overdominance and underdominance) in a large random-mating population. The selection response and the limits of the selective process were studied by deterministic simulation. The lifetime of the process was generally between 20 and 100 generations and did not appear to depend on the mode of natural selection. However, depending on the values of the parameters (initial gene frequency, selection intensity, ratio of the effect of the gene to the environmental standard deviation, fitness values) the following outcomes of selection were observed: fixation of the allele favored by artificial selection, stable nontrivial equilibrium, unstable equilibrium and loss of the allele favored by artificial selection. Finally, the results of the simulation were compared to the results of selection experiments.

scholarly journals Natural Selection at an Exceptionally Long GGC Repeat in the Human RASGEF1C and Divergent Genotypes in Late-onset Neurocognitive Disorder

2021 ◽  
Author(s):  
Z Jafarian ◽  
S Khamse ◽  
H Afshar ◽  
Khorram Khorshid HR ◽  
A Delbari ◽  
...  
Keyword(s):  
Natural Selection ◽  
Evolutionary Biology ◽  
Late Onset ◽  
Core Promoter ◽  
Human Subjects ◽  
Specific Gene ◽  
Protein Coding ◽  
Repeat Allele ◽  
Complex Disorders ◽  
Selection For

Abstract Across the human protein-coding genes, the neuron-specific gene, RASGEF1C, contains the longest (GGC)-repeat, spanning its core promoter and 5′ untranslated region (RASGEF1C-201 ENST00000361132.9). RASGEF1C expression dysregulation occurs in late-onset neurocognitive disorders (NCDs), such as Alzheimer’s disease. Here we sequenced the GGC-repeat in a sample of human subjects (N = 269), consisting of late-onset NCDs (N = 115) and controls (N = 154). We also studied the status of this STR across vertebrates. The 6-repeat allele of this repeat was the predominant allele in the controls (frequency = 0.85) and NCD patients (frequency = 0.78). The NCD genotype compartment consisted of an excess of genotypes that lacked the 6-repeat (Mid-P exact = 0.004). We also detected divergent genotypes that were present in five NCD patients and not in the controls (Mid-P exact = 0.007). This STR expanded beyond 2-repeats specifically in primates, and was at maximum length in human. We conclude that there is natural selection for the 6-repeat allele of the RASGEF1C (GGC)-repeat in human, and significant divergence from that allele in late-onset NCDs. Indication of natural selection for predominantly abundant STR alleles and divergent genotypes enhance the perspective of evolutionary biology and disease pathogenesis in human complex disorders.

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