Related Experiment Video
Updated: Aug 18, 2025
05:19
Isolation and Identification of Bacterial Strains from Skin of Terrestrial Amphibians
Published on: June 17, 2025
640
Different Traits, Different Evolutionary Pathways: Insights from Salamandrina (Amphibia, Caudata)
Claudio Angelini1, Francesca Antonucci2, Jacopo Aguzzi3
1Salamandrina Sezzese Search Society, Via G. Marconi 30, 04018 Sezze, Italy.
Animals : an Open Access Journal From MDPI
|December 11, 2022
Summary
Species delimitation using multiple traits reveals high intra-specific variability in size and shape, challenging traditional methods. Habitat influences traits differently, suggesting diverse evolutionary paths for salamander species.
Area of Science:
- Evolutionary Biology
- Speciation Studies
- Quantitative Genetics
Background:
- Traditional species delimitation often relies on limited traits, potentially causing misinterpretations and obscuring evolutionary processes.
- The genus *Salamandrina* presents a challenge due to phenetic similarity between its two species, despite molecular divergence.
- Understanding phenotypic diversity is crucial for accurate species delimitation and inferring evolutionary histories.
Purpose of the Study:
- To investigate the diversity patterns of multiple phenotypic traits (size, shape, head color) in the *Salamandrina* genus.
- To compare species delimitation accuracy using single versus multiple phenetic traits within a model comparison framework.
- To explore the influence of population and habitat on phenotypic variation and identify potential evolutionary drivers.
Main Methods:
- Analysis of multiple phenetic traits: size, external body shape, and head color pattern.
- Application of a model comparison framework utilizing non-linear mixed models.
- Employing unsupervised and supervised clustering techniques for data analysis.
Main Results:
- High intra-specific variability observed in body size and shape, influenced by population and habitat.
- Phenotypic differences between *Salamandrina* species were generally less pronounced than intra-specific variation.
- Habitat significantly impacts head color pattern, suggesting localized adaptation, while other traits may follow different evolutionary routes.
Conclusions:
- Relying on single traits for species delimitation can be misleading; multiple traits are essential for a comprehensive understanding.
- Population-level variability must be considered when assessing higher-level taxonomic distinctions.
- Phenotypic traits can evolve independently, driven by factors like local adaptation and genetic drift, necessitating multi-faceted approaches in evolutionary studies.
Related Concept Videos
01:54Convergent Evolution
28.2K
Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.
28.2K
01:07Speciation Rates
21.3K
Overview
21.3K
01:15Diversity of Protists I
82
Excavata is a diverse group of protists that includes both chemoorganotrophic and phototrophic species, with some thriving in anaerobic environments. Among the key groups within Excavata are diplomonads and parabasalids, which are flagellated protists that lack mitochondria and chloroplasts. These microorganisms typically inhabit anoxic environments, such as the intestines of animals, where they exist either symbiotically or as parasites, relying on fermentation for energy production. Some...
82
02:27Background and Environment Affect Phenotype
6.6K
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
6.6K
02:55The Evidence for Evolution
43.3K
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.
43.3K
01:46Types of Selection
41.2K
Natural selection influences the frequencies of particular alleles and phenotypes within populations in several different ways. Primarily, natural selection can be directional, stabilizing, or disruptive. Directional selection favors one extreme trait and shifts the population towards that phenotype while selecting against individuals displaying alternate traits. Stabilizing selection favors an intermediate trait with a narrow range of variation. Deviation from the optimal phenotype towards an...
41.2K