Affiliation:
1. Department of Ecology and Evolutionary Biology, Yale University , 165 Prospect St, New Haven, CT 06511 , USA
2. Department of Biological Sciences, University of Alabama , 1325 Hackberry Ln, Tuscaloosa, AL 35401 , USA
Abstract
Abstract
Adaptive radiation involves diversification along multiple trait axes, producing phenotypically diverse, species-rich lineages. Theory generally predicts that multi-trait evolution occurs via a “stages” model, with some traits saturating early in a lineage’s history, and others diversifying later. Despite its multidimensional nature, however, we know surprisingly little about how different suites of traits evolve during adaptive radiation. Here, we investigated the rate, pattern, and timing of morphological and physiological evolution in the anole lizard adaptive radiation from the Caribbean island of Hispaniola. Rates and patterns of morphological and physiological diversity are largely unaligned, corresponding to independent selective pressures associated with structural and thermal niches. Cold tolerance evolution reflects parapatric divergence across elevation, rather than niche partitioning within communities. Heat tolerance evolution and the preferred temperature evolve more slowly than cold tolerance, reflecting behavioral buffering, particularly in edge-habitat species (a pattern associated with the Bogert effect). In contrast to the nearby island of Puerto Rico, closely related anoles on Hispaniola do not sympatrically partition thermal niche space. Instead, allopatric and parapatric separation across biogeographic and environmental boundaries serves to keep morphologically similar close relatives apart. The phenotypic diversity of this island’s adaptive radiation accumulated largely as a by-product of time, with surprisingly few exceptional pulses of trait evolution. A better understanding of the processes that guide multidimensional trait evolution (and nuance therein) will prove key in determining whether the stages model should be considered a common theme of adaptive radiation.
Funder
National Science Foundation
MacMillan International Dissertation Research
Publisher
Oxford University Press (OUP)
Reference107 articles.
1. Niche evolution and adaptive radiation: testing the order of trait divergence;Ackerly;Ecology,2006
2. Niche incumbency, dispersal limitation and climate shape geographical distributions in a species-rich island adaptive radiation;Algar;Glob. Ecol. Biogeogr,2013
3. The influence of physical conditions in the genesis of species;Allen;Radical review,1877
4. Comparison of hydric and thermal physiology in an environmentally diverse clade of Caribbean anoles;Alomar;Integr. Comp. Biol.,2024
5. Integrated phenotypes: understanding trait covariation in plants and animals;Armbruster;Philos. Trans. R. Soc. London, Ser. B,2014