Date of Award

Fall 2022

Document Type

Open Access Thesis


Biological Sciences

First Advisor

Ward B. Watt


In a process known as the evolutionary recursion, it is possible to follow how adaptation affects natural selection at successive stages of a species’ life cycle. Through studying allele and genotype frequencies of enzymes in glycolysis, a central metabolic pathway, it is possible to document how polymorphisms can shift the evolving functionality of enzymes within or among species. Fructose-1,6-bisphosphatase (FBPase) is an enzyme in gluconeogenesis that converts fructose-1,6-bisphosphate to fructose 6- phosphate. It is also known to convert the unused amino acid carbon skeletons of glycolysis into glycogen storage. Appearing to play a vital role in the acquisition, storage, and redistribution of carbon skeleton resources derived from larval feeding throughout an individual’s lifetime, FBPase could be influential in adaptation leading to diverging life history strategies. FBPase from seven isolated populations of North American Colias butterflies (four C. meadii, two C. eriphyle, and one C. eurytheme) were sequenced. Within C. meadii, we sampled on an elevational gradient both above and below tree line. We first tested the neutral null hypothesis that states any present genetic variation will be neutral. FBPase variation is not neutral, and once the null was violated, we hypothesized that a.) there will be a decrease in FBPase variation as elevation increases within species and b.) there will be a positive phylogentic correlation to variation among species. Strong purifying selection is acting on FBPase nonsynonymous variants. Based on a linear regression, elevation does not have an effect on FBPase variation within C. meadii. Among species, there is no positive phylogenetic correlation to FBPase variation. While initially surprising, the lack of a phylogenetic relationship between Colias and FBPase variation now allows for questions to be asked about varying life history strategies that also do not follow phylogenetic relationships. By studying the genetic variation of FBPase, in combination with future field studies, we will be able to directly relate genotypes to performance.


© 2022, Andrea Blair Stokes

Included in

Biology Commons