Research

Conservation Paleobiology: Linking the past to the present, for the future

Understanding species responses to past environmental perturbations will better prepare us to assess how species will be affected by ongoing and future environmental change. In a recent review paper (Kemp and Hadly 2016, Journal of Vertebrate Paleontology), I outlined “detectable responses” and “assessment strategies” through which conservation paleobiology can contribute to real-world assessment and conservation strategies. However, the assessment and conservation of biodiversity requires perspective not only from the past, but also the present. My research capitalizes on advances in these and other tools as they pertain not only to the fossil record, but also to modern communities, thereby bridging these two time points. Our research interests include:

Vertebrate Paleobiology of the Tropics

Fossils provide an unparalleled opportunity to see how environmental perturbations have affected past populations, and data from the study of fossils serve as predictive tools to evaluate extinction risk in modern-day populations.  Integration of paleontological data with ecological data is especially needed in the tropics, a region with many biodiversity hotspots, high human populations, and high rates of habitat loss. Historically, there has been a paucity of paleontological fieldwork in the tropics, due in part to conditions that are less conducive to fossilization, but my colleagues and I have unearthed highly diverse faunal assemblages in the Caribbean and elsewhere. We will continue to work in the Caribbean and other tropical localities, focusing on Quaternary deposits.

Melissa Marie Galante

Responses to global change

While some taxonomic groups underwent extinction following Quaternary perturbations, others persisted, and some even diversified. We seek to understand the responses that different taxa have to biotic and abiotic perturbations through time, and we use tools such as stable isotopes, morphometrics, and genetics (both ancient DNA and modern DNA) to track diversity within populations before, during, and after encounters with environmental perturbations related to global change, such as sea-level fluctuations, species introductions, and habitat loss. These studies will help articulate if species persistence in a changing world is directly linked to specific traits and/or the ability to adapt rapidly. The data generated with these tools can also be used to place extinct taxa into phylogenetic contexts, and answer questions about character evolution, diversification rates, and the biogeography of colonization and extinction in insular systems more broadly.

Body size evolution, extinction, and extinction risk

Over the course of the Pleistocene and into the Holocene, a multitude of taxa went extinct. Previous studies, including our own work in lizards, have shown that these extinctions were size-biased and lineage specific. We remain interested in body size evolution in reptiles, and use the fossil record to articulate the full breadth of diversity in this group, as well as how this diversity changes at different intervals of time. We are also interested in determining what other traits correspond to elevated extinction risk, and using this information to make predictions about extinction risk for extant squamates, especially species that are poorly described.

Validating predictions from the fossil record with ecological studies

Our previous research indicates that extinction events can have long-lasting effects on community structure. We regularly use ecological information to inform our paleontological results, and we seek to use paleontological data to evaluate predictions about present-day species interactions. Thus, we will conduct long-term enclosure experiments to evaluate predictions we’ve made (about competition, predator-prey interactions, and ecological release, among other things) from looking at paleoecological data. Such experiments directly follow from the prehistoric events that we have documented in the Caribbean, but perhaps more importantly, it presages the novel communities that will be a result of increased extirpation, extinction, and colonization—phenomena that will continue to accelerate in the future—making it essential to know what effect changing community composition will have on the species that make up the community.

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Why the Caribbean? The Caribbean is nature’s laboratory, rivaling famous island ecosystems like the Galapagos in its beauty, diversity, and complexity. Despite efforts to understand present patterns of biodiversity, little is known about the ancient Caribbean, an island system that has been impacted by significant environmental perturbations: multiple human colonization events, significant island area change due to sea-level fluctuations, and episodic natural disasters: hurricanes, volcanic eruptions, and earthquakes principle among them.

Why Lizards? Lizards are the most diverse vertebrate taxa in the Caribbean, with several lineages—including the iconic Anolis lizards—occupying islands of every size, substrate and age. Lizards inhabit a vast array of habitats, exhibit high phenotypic plasticity, and display rapid rates of morphological evolution, rendering them an excellent model system for evolutionary studies. While our research focuses primarily on lizards in the Caribbean, we are open to pursuing the aforementioned research objectives in other taxonomic groups and geographic regions.

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