This Is AuburnElectronic Theses and Dissertations

Understanding extinction risk in aquatic invertebrates using range size and genetic diversity




Garugu, Surya Deepika

Type of Degree

Master's Thesis


Forestry and Wildlife Science

Restriction Status


Restriction Type

Auburn University Users

Date Available



Genetic diversity is not only necessary for evolutionary processes but also for ecosystem functioning and population stability. This is particularly true for ecosystem engineers that contribute broadly to function and food webs in the habitats in which they are found. In this study, we assessed the global patterns of extinction risk, range size, and genetic diversity, specifically focusing on two large invertebrate clades: Mollusca and Arthropoda. We collected data from the International Union for Conservation of Nature (IUCN) and also conducted a systematic, quantitative review of existing Mollusca and Arthropoda nuclear and mitochondrial data. In total we considered 4075 species evaluated by the IUCN as well as 2452 populations with genetic data. We found that range size is significantly smaller in critically endangered species compared to least concern species, but that genetic diversity did not vary significantly between extinction risk categories. However, when we considered the variability in genetic diversity between populations within a species, we found that mollusks are significantly more variable than arthropods in the nuclear genome but not the mitochondrial genome. Combined, this suggests that future efforts aimed at identifying extinction risk using genetic data will need to consider taxonomic biases when applying population-level assessments to species-level determinations.