Distinguishing species boundaries from geographic variation.

Area of Science:

• Genomics
• Evolutionary Biology
• Taxonomy

Background:

• Accurate species delimitation is vital amidst global biodiversity loss.
• Distinguishing intraspecific variation from interspecific variation poses challenges, especially in widespread species.
• Genetic variation within widespread species can mimic differences between distinct species, leading to taxonomic inflation.

Purpose of the Study:

• To develop and apply a workflow for differentiating intra- and interspecific genetic variation.
• To address taxonomic issues within the widely distributed Rana pipiens complex (leopard frogs).
• To provide a framework for robust species delimitation, emphasizing evidence of reproductive isolation.

Main Methods:

• Utilized genome-scale datasets paired with model-based species delimitation methods.
• Applied a novel workflow to analyze genetic variation in the Rana pipiens complex.
• Focused on identifying positive evidence for reproductive isolation to validate species boundaries.

Main Results:

• Demonstrated that intraspecific geographic variation in leopard frogs has led to significant taxonomic inflation.
• Found that ten currently recognized species within the complex are not supported by the data and are synonymized.
• Identified positive evidence for three previously undescribed species within the complex.

Conclusions:

• The proposed workflow effectively distinguishes intra- and interspecific genetic variation.
• Taxonomic inflation in the Rana pipiens complex is reduced by synonymizing ten unsupported species.
• Three new species are identified, contributing to a more accurate understanding of leopard frog diversity. Recommendations are provided for refuting these findings, promoting scientific rigor.