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1. Adaptive Radiation Without Independent Stages of Trait Evolution in a Group of Caribbean Anoles

   https://doi.org/10.1093/sysbio/syae041  

   Bodensteiner, Brooke; Burress, Edward D; Muñoz, Martha M (August 2024, Systematic Biology)

   Burbrink, Frank (Ed.)

   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. 

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2. Scaling between macro‐ to microscale climatic data reveals strong phylogenetic inertia in niche evolution in plethodontid salamanders

   https://doi.org/10.1111/evo.13959  

   Farallo, Vincent R.; Munoz, Martha M.; Uyeda, Josef C; Miles, Donald B. (March 2020, Evolution)

   Weisrock, David (Ed.)

   Macroclimatic niches are indirect and potentially inadequate predictors of the realized environmental conditions that many species experience. Consequently, analyses of niche evolution based on macroclimatic data alone may incompletely represent the evolutionary dynamics of species niches. Yet, understanding how an organisms’ climatic (Grinnellian) niche responds to changing macroclimatic conditions is of vital importance for predicting their potential response to global change. In this study, we integrate microclimatic and macroclimatic data across 26 species of plethodontid salamanders to portray the relationship between microclimatic niche evolution in response to changing macroclimate. We demonstrate stronger phylogenetic signal in microclimatic niche variables than at the macroclimatic scale. Even so, we find that the microclimatic niche tracks climatic changes at the macroscale, but with a phylogenetic lag at million‐year timescales. We hypothesize that behavioral tracking of the microclimatic niche over space and phenology generates the lag: salamanders preferentially select microclimates similar to their ancestral conditions rather than adapting with changes in physiology. We demonstrate that macroclimatic variables are weak predictors of niche evolution and that incorporating spatial scale into analyses of niche evolution is critical for predicting responses to climate change. 

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3. Predicting climate change impacts on poikilotherms using physiologically guided species abundance models

   https://doi.org/10.1073/pnas.2214199120  

   Wagner, Tyler; Schliep, Erin M.; North, Joshua S.; Kundel, Holly; Custer, Christopher A.; Ruzich, Jenna K.; Hansen, Gretchen J. (April 2023, Proceedings of the National Academy of Sciences)

   Poikilothermic animals comprise most species on Earth and are especially sensitive to changes in environmental temperatures. Species conservation in a changing climate relies upon predictions of species responses to future conditions, yet predicting species responses to climate change when temperatures exceed the bounds of observed data is fraught with challenges. We present a physiologically guided abundance (PGA) model that combines observations of species abundance and environmental conditions with laboratory-derived data on the physiological response of poikilotherms to temperature to predict species geographical distributions and abundance in response to climate change. The model incorporates uncertainty in laboratory-derived thermal response curves and provides estimates of thermal habitat suitability and extinction probability based on site-specific conditions. We show that temperature-driven changes in distributions, local extinction, and abundance of cold, cool, and warm-adapted species vary substantially when physiological information is incorporated. Notably, cold-adapted species were predicted by the PGA model to be extirpated in 61% of locations that they currently inhabit, while extirpation was never predicted by a correlative niche model. Failure to account for species-specific physiological constraints could lead to unrealistic predictions under a warming climate, including underestimates of local extirpation for cold-adapted species near the edges of their climate niche space and overoptimistic predictions of warm-adapted species. 

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4. The Andes are a driver of physiological diversity in Anolis lizards

   https://doi.org/10.1093/evolinnean/kzae040  

   Salazar, Jhan C; Londoño, Gustavo A; Muñoz, Martha M; Miles, Donald B; Castañeda, María_del Rosario (January 2025, Evolutionary Journal of the Linnean Society)

   Abstract The Andes, with its diverse topography and climate, is a renowned cradle for adaptive radiation, particularly for vertebrate ectotherms such as lizards. Yet, the role of temperature in promoting physiological specialization in the Andes remains unclear. Aseasonality in the tropics should favour physiological specialization across elevation in lizards, but empirical data are limited and equivocal. Determining how thermal tolerances are geographically and phylogenetically structured is therefore a priority, particularly as environments continue to change rapidly. However, there is a gap in our knowledge of thermal limits of species from the Andes, one of the planet’s most biodiverse regions. Anoles, a diverse lizard group found across thousands of metres of elevation in the Andes, can offer insights into evolutionary adaptations to temperature. This study focused on 14 anole species from two clades (Dactyloa and Draconura) that independently diversified along elevational gradients in the Andes. We measured critical thermal limits (CTmin and CTmax) and found patterns of thermal tolerance specialization across elevation, both among and within species. Patterns of thermal specialization are similar among anole clades, indicating parallel responses to similar environmental pressures. Specifically, high-elevation anoles are more cold tolerant and less heat tolerant than their low-elevation counterparts, rendering thermal tolerance breadths stable across elevation (thermal specialization). Evolutionary rates of physiological traits were similar, reflecting parallel specialization in heat and cold tolerance across elevation. The adaptive radiation of anole lizards reflects physiological specialization across elevation, and the endemism such specialization favours, probably catalysed their remarkable diversity in the tropical Andes. 

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5. General laws of biodiversity: Climatic niches predict plant range size and ecological dominance globally

   https://doi.org/10.1073/pnas.2517585122  

   Moulatlet, Gabriel M; Merow, Cory; Maitner, Brian; Boyle, Brad; Feng, Xiao; Frazier, Amy E; Hinojo-Hinojo, Cesar; Newman, Erica A; Roehrdanz, Patrick R; Song, Lei; et al (November 2025, Proceedings of the National Academy of Sciences)

   A longstanding question in ecology asks whether or not species that achieve large geographic ranges also have large climatic niche breadths. Using a dataset of ~250,000 terrestrial plant species spanning diverse clades (bryophytes, ferns, gymnosperms, and flowering plants), we demonstrate a consistent positive relationship between geographic range size and climatic niche breadth across latitudinal and elevational gradients. This relationship holds across major phylogenetic groups, suggesting a general biogeographical rule for range size variation. Our findings indicate that latitudinal and elevational gradients in range size arise from selective pressures and species sorting based on climatic tolerance. Additionally, we show that species with larger range sizes tend to be ecologically dominant, supporting a long-suspected connection between range size, niche breadth, and local and regional abundance. Our results suggest a spectrum of dominance, where species with extensive geographic ranges and broader climatic tolerances tend to be more abundant. We posit that the relationship between range size, niche breadth, and ecological dominance is an emergent macroecological pattern that can be used for understanding and predicting the impacts of climate change on species distributions. 

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