The scarcity of asexual reproduction in vertebrates alludes to an inherent cost. Several groups of asexual vertebrates exhibit lower endurance capacity (a trait predominantly sourced by mitochondrial respiration) compared to congeneric sexual species. Here we measure endurance capacity in five species of Aspidoscelis lizards and examine mitochondrial respiration between sexual and asexual species using mitochondrial respirometry. Our results show reduced endurance capacity, mitochondrial respiration, and phenotypic variability in asexual species compared to parental sexual species along with a positive relationship between endurance capacity and mitochondrial respiration. Results of lower endurance capacity and lower mitochondrial respiration in asexual Aspidoscelis are consistent with hypotheses involving mitonuclear incompatibility.

This repository includes files with DNA sequence alignments, evolutionary relationships, mitochondrial respiration, and endurance measurements for five species of whiptail lizards. Code used to analyze the data in the context of the study is also included.