Polymorphism as a precursor to speciation in a California endemic salamander

The salamander species Batrachoseps stebbinsi is an underrepresented subject in morphological studies. Authors have noted morphological differences and genetic divergence between northern and southern populations. This has led to speculation as to whether or not the northern and southern populations are separate species due to their observed morphological differences and the apparent gap in their distribution. To date, no formal analysis of range-wide morphological data has been published.  This study aims to quantify the morphology and shape differences (body and limb proportions) between northern and southern populations of B. stebbinsi. The role of sexual dimorphism and size at maturity will be included in the analysis. Whether selection is driving the observed variation in color and shape differences is not yet known. Statistical difference was found between populations. This poster has been presented at the 20205 Amphibian Task Force Conference and the 2025 UCSB Undergraduate Research Colloquium.