Related Experiment Video
Updated: Jun 23, 2026
07:44
Measuring Microbial Mutation Rates with the Fluctuation Assay
Published on: November 28, 2019
The adaptive accuracy of flowers: measurement and microevolutionary patterns
W Scott Armbruster1, Thomas F Hansen, Christophe Pélabon
1University of Portsmouth, UK. scott.armbruster@port.ac.uk
Annals of Botany
|May 12, 2009
Summary
This study introduces adaptive inaccuracy as a measure of evolutionary deviation from optimal traits in flowers. It reveals significant variation in accuracy among species, influenced by developmental changes and pollinator interactions, highlighting conflicting selective pressures.
Area of Science:
- Evolutionary Biology
- Plant Reproductive Ecology
- Quantitative Genetics
Background:
- Historically, adaptation has been viewed as evolution towards optimal traits, but the causes of deviations from these optima remain under-assessed.
- This study investigates adaptive inaccuracy, defined as phenotypic deviation from optimal trait values, using floral pollination systems as a model.
Purpose of the Study:
- To measure and analyze the components of adaptive inaccuracy in floral systems.
- To explore the factors contributing to deviations from adaptive optima in plant reproduction.
Main Methods:
- Decomposition of adaptive inaccuracy into components: optimality (mean deviation) and precision (trait variance) for individuals and populations.
- Inclusion of additional population-level components: variance in genotypic targets and within-population variation in optima.
- Estimation of male and female inaccuracy in flowers based on pollen deposition and stigma contact relative to adaptive optima.
Main Results:
- Substantial variation in adaptive accuracy was observed within and across species.
- Developmental changes during anthesis and pollinator immobility during pollen transfer influence accuracy.
- Conflicting selective pressures, such as those promoting herkogamy, contribute to significant deviations from adaptive optima.
Conclusions:
- Adaptive accuracy provides a valuable framework for understanding the adaptive significance of phenotypic variation in floral morphology.
- Analyzing components of adaptive inaccuracy helps identify causes like conflicting selection, low canalization, and developmental instability.
Related Concept Videos
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...
02:54Evolutionary Relationships through Genome Comparisons
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
02:55The Evidence for Evolution
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution.
03:33Genetic Drift
Natural selection—probably the most well-known evolutionary mechanism—increases the prevalence of traits that enhance survival and reproduction. However, evolution does not merely propagate favorable traits, nor does it always benefit populations.Life is not fair. A deer grazing contentedly in a field can have her meal cut tragically short by a bolt of lightning. If the doomed doe is one of only three in the population, 1/3 of the population’s gene pool is lost. Random events like this can...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
02:39Gene Flow
Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.