Adaptive Radiation in Miniopterus? Effects of Competitive Milieu on Ecomorphological Divergence

The evolutionary processes shaping morphological diversity within the genus Miniopterus are examined through an investigation into adaptive radiation among African and Malagasy bat species, focusing on wing morphology. Using linear measurements from ethanol-preserved specimens in the Field Museum of Natural History’s mammal collection, we examined morphospace distribution through Principal Component Analysis (PCA). Results show that Miniopterus species cluster primarily by size, with the first principal component, representing a size gradient, accounting for 77.4% of the observed variance. Integrating a phylomorphospace analysis with the latest Miniopterus phylogeny, we explored how evolutionary history, presence or absence of other clutter-edge bat families, and geographic distribution influence morphological diversity. Euclidean distance matrices between centroid measurements demonstrated that nearest neighbor species in both Africa and Madagascar exhibit close morphological resemblances, with similar average and farthest neighbor distances across regions.Further, a multivariate dispersion analysis yielded a mean dispersion value of 3.30, which does not differ significantly from random (p = 0.681), suggesting limited niche differentiation. Consequently, we fail to reject the null hypothesis, finding limited evidence for adaptive radiation based on the examined wing traits. This research offers insights into the evolutionary dynamics shaping morphological diversity in Miniopterus, emphasizing the need to consider a broader array of ecological factors to fully understand adaptive radiation and contribute to a holistic view of evolutionary processes in bats.