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Predicting the effects of anthropogenic climate change on Earth’s marine mollusk species is highly relevant, as many are critical human food resources and indispensable members of marine ecosystems. To predict which species will go extinct and which will survive, it is essential to understand the past climate species have experienced, as well as determine the relationship between functional traits, which provide a direct connection to organismal ecology, and survival. Many extant West Atlantic (WA) mollusks, especially gastropods and bivalves, survived the Mid-Pliocene Warm Period and the Last Interglacial, warm intervals compared to the present, that can serve as analogues for predicted future conditions of anthropogenic climate change. WA mollusks have an exceptional Neogene fossil record, which makes them an ideal group to study to develop a predictive extinction risk framework. The present research focuses on the correlation between functional traits and extinction in over 80 species of WA mollusks, both extant and extinct. Functional trait data such as body size, mobility, diet, bathymetric depth range, and organism-substrate relationship, which correlate with metabolic requirements, a known factor in extinction risk, and degree and type of ornamentation, shell shape in bivalves, and narrowness of the aperture in gastropods, which correlate with predation resistance, were collected across these species. These comprise both continuous and discrete character data. Various statistical tests were applied to the database to examine variable correlation/interaction, and the relative contributions of traits to extinction risk. Traits related to metabolism were strong predictors of survival; traits related to predation resistance play a less important role. While this study focuses on organismic traits, the aim of future research will be to explore how group characteristics such as geographic range are associated with functional traits and extinction risk for these species. A predictive framework is developed using patterns of extinction in the fossil record to infer survival of various species in the future, which will be relevant for evaluating the potential consequences of climate change, global change biology, and for determining which species should be targeted for conservation efforts.
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ESTIMATING THE NET EFFECT OF FUNCTIONAL TRAITS ON EXTINCTION IN PLIOCENE TO MODERN MOLLUSKS
The influence of functional traits on species survivorship has been evaluated in various contexts in both modern and ancient ecosystems, but an important direction for research is to integrate datasets that include both extinct and extant taxa. This approach can provide a more reliable understanding of the effects of functional traits on macroecological and macroevolutionary dynamics. Knowledge of the links between individual traits and survivorship is crucial for developing accurate extinction risk predictive models. Here we test the impact of numerous functional traits on the survival and extinction of species through time, using bivalve and gastropod species from the rich fossil record of the western Atlantic over the last ~3 million years, along with the associated extant biota. We also compare the impact of these organismic traits on survival relative to a group level trait: geographic distribution. Analyses use a dataset of 12 functional traits including life habit, feeding behavior and basal metabolic rate (BMR), for 115 species from 36 families. Traits were observed and measured from specimens in the collections of the Paleontological Research Institution, Florida Museum of Natural History, and University of Kansas, as well as surveys of the literature and online databases such as the Neogene Marine Biota of Tropical America (NMITA). Results derived from Principal Coordinates Analysis (PCoA) show there is a clear distinction between extinct and extant species, overall, when comparing them based on life habit, maximum body size, shell composition and BMR. Most traits showed little direct relation with survival, except BMR and associated maximum body size, supporting the Metabolic Theory of Ecology. Since many functional traits do not explain survival, their function may be mis- or over-interpreted, and traits posited to represent important organismic adaptations may not play a prominent role in long-term species survival, especially during the major climate changes over the last ~ 3 million years. Some traits do show significant interactions, and these were more fully explored using additional multivariate analyses. The relative importance of geographic range size suggests group-level characters may be the primary determinant of extinction patterns over macroevolutionary time scales.
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- Award ID(s):
- 2225014
- PAR ID:
- 10479906
- Publisher / Repository:
- Geological Society of America
- Date Published:
- Journal Name:
- Geological Society of America Abstracts with Programs
- Volume:
- 55
- Issue:
- 6
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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