Testing the Niche Center Hypothesis on Pleistocene Bivalves from the Gulf Coast

Rhiannon Nolan, MS, PhD Student

Earth & Planetary Sciences
Mentor: Corinne Myers

Ecological niche models (ENMs) have been widely applied to modern fauna to test abiotic niche characteristics and distributional dynamics.

We apply them here to test the Niche Center Hypothesis (NCH), which predicts a negative relationship between species abundance and distance to the center of the species’ fundamental niche in environmental space. Modern tests are inconclusive; however, a deep-time analysis may improve fundamental niche models.

Marine bivalve species occurring throughout the Pleistocene and Holocene extend our NCH analysis over geological timescales (0–2.8 Ma).

ENM models and analysis of distance distributions from the niche center do not support NCH relationships among these taxa, which suggests that biogeographical abundant centers are likely complex when present and should not be broadly assumed regardless of species.