Date of Award

Fall 2022

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Biology

Committee Chairperson

Jennifer Maresh, Ph.D.

Committee Member

Greg Turner, Ph.D.

Committee Member

Michael Rosario, Ph.D.

Committee Member

Chris Law, Ph.D.

Abstract

Scincidae is one of the most diverse families of squamates, comprising over 1,300 species of lizards with a variety of life history and ecological traits. This diversity includes three reproductive modes, where some species reproduce via oviparity (egg-laying), viviparity (live birth) or use of a mixed strategy (females switch modes). In this study, it was sought whether reproductive output differs between scincid species using these reproductive modes. Reproductive output is defined as the average product of offspring abundance and size per reproductive event, representing the reproductive effort of an individual. Additionally, the importance of phylogeny (evolutionary relatedness) and a suite of eco-physiological variables in determining reproductive output in scincid mothers were tested. The dataset included 295 scincid species for which these variables were available in the literature. A phylogenetic comparative analysis indicated scincid reproductive output follows similar scaling patterns as other taxonomic groups, with female body size explaining ~86% of the variation in total offspring mass. Size-corrected offspring mass was best explained by a phylogenetic linear model, with most scincid species producing ~21% of maternal body mass per reproductive event. The results share similarities with other animal taxa supporting the possible existence of universal scaling patterns of production rates across animal taxa. These data highlight the importance of formulating a comprehensive phylogenetic comparative analysis of the drivers of reproductive output across animal taxa to determine how natural selection favors the evolution of reproductive strategies that maximize offspring viability and lifetime fitness.

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