Biology subjects

Buckley, L.

Publications and source records attributed to Buckley, L..

4 recordsLinked to original sources

bioRxiv2025

Climate change induced selection on and evolution of insect thermal sensitivity

How have recent changes in temperature means and variability altered selection on and evolution of the thermal sensitivity of insect growth? We address this question for cabbage white butterflies, Pieris rapae, by repeating a 1999 study that linked lab measurements of the temperature sensitivity of short-term growth rates to fitness components (survival, development time, final body size, and fecundity) in the field. In 1999, selection favored increased growth at low temperatures at the expense of decreased growth at high temperatures. We document evolution consistent with this past selection: caterpillars now grow faster at low temperatures but slower at warm temperatures in 2024 compared to 1999. However, temperatures have changed rapidly, with increasing incidence of high temperatures such that selection in 2024 has reversed to favor increased growth at the highest temperature assayed. Over the 25 years, phenotypic variation has increased at warm temperatures and a tradeoff between growth at intermediate and warm temperatures has strengthened, consistent with evolutionary constraints that may restrict evolution to grow faster at rare, high temperatures. Our study demonstrates the potential for rapid evolution of thermal sensitivity in response to climate change in an agricultural pest. However, selection to initially capitalize on warming temperatures can ultimately decrease fitness as warming temperatures move into a stressful range, driving reversals in the direction of selection.

ecology↗

bioRxiv2025

Functional resurveys and models reveal the interplay of plasticity and evolution of Pierid butterflies in response to recent climate change

The extent of contemporary evolution, which is mediated by interactions with plasticity, will be an important determinant of biological responses to climate change. We synthesize two functional resurvey projects that, coupled with mechanistic models, evaluate the interplay of plasticity and evolution of Pierid butterfly larval (thermal sensitivity of feeding) and adult (wing melanization) traits over recent decades. We characterize thermal environments over the resurvey periods, which we interface with developmental and (historical, current, and hypothetical) thermal sensitivity traits to examine the implications of evolutionary changes. We find that the evolution of photoperiod-cued plasticity of wing melanization in California Colias is consistent with avoiding thermal stress during warming springs. Plasticity has not evolved for Colorado Colias populations, which have experienced stronger increases in climate means relative to extremes in recent decades. Evolution in Colorado Colias larvae has improved tolerance to warm extremes, whereas evolution in California Colias larvae has broadened thermal sensitivity consistent with capitalizing on expanded seasonal thermal opportunity. Our models predict that Washington Pieris larvae have experienced shifts in the direction of selection to increase performance at warm temperatures. The research highlights the importance of evaluating changes in climate change exposure and sensitivity to understand interacting organismal responses.

evolutionary biology↗

bioRxiv2024

Insect size responses to climate changes vary across elevations according to seasonal timing

Widespread plastic and evolutionary responses to temperature have led to body size declines being proposed as a universal response to warming, but the high degree of variation in terrestrial ectotherms has challenged this view. We investigate whether temperature dependent development and growth rates in ectothermic organisms drive departures from universal size responses. Leveraging a long-term study of montane grasshoppers, we detect size shifts over recent decades that depend on elevation and species seasonal timing. Size shifts have been focused at low elevations with the earliest emerging species (those that overwinter as juveniles) getting bigger, and later season species getting smaller. The shifts correspond to warmer temperatures at low elevation increasing the sizes of the earliest season species but decreasing the sizes of the later season species. This is consistent with our hypothesis that the earliest season species may be able to take advantage of warmer conditions accelerating growth during early spring development, whereas warm temperatures may adversely impact later season species via mechanisms such as increased rates of energy use or thermal stress. Grasshoppers tend to capitalize on warm conditions by both getting bigger and reaching adulthood earlier. Our analysis further reinforces the need to move beyond expectations of universal responses to climate change to consider how environmental exposure and sensitivity varies across elevations and life histories.

ecology↗

bioRxiv2017

Metabolism constrains bird and mammal ranges and predicts shifts in response to climate change

AimWe test whether physiological constraints on maximum metabolic rate and the factor by which endotherms can elevate their metabolism (metabolic expansibility) govern cold range limits for mammal and bird species.\n\nLocationGlobal\n\nMethodsWe examine metabolic expansibility at the cold range boundary (MEO_SCPLOWCRBC_SCPLOW) and its trait predictors and then use MEO_SCPLOWCRBC_SCPLOW to project range shifts for 210 mammal and 61 bird species.\n\nResultsWe find evidence for metabolic constraints: the distributions of metabolic expansibility at the cold range boundary peak at similar values for birds (2.7) and mammals (3.2). The right skewed distributions suggest some species have adapted to elevate or evade metabolic constraints. Mammals exhibit greater skew than birds, consistent with their diverse thermoregulatory adaptations and behaviors. Mammal and bird species that are small and occupy low trophic levels exhibit high levels of MEO_SCPLOWCRBC_SCPLOW. Mammals with high MEO_SCPLOWCRBC_SCPLOW tend to hibernate or use torpor. Predicted metabolic rates at the cold range boundaries represent large energetic expenditures (>50% of maximum metabolic rates). We project species to shift their cold range boundaries poleward by an average of 3.9{degrees} latitude by 2070.\n\nMain conclusionsOur analysis suggests that metabolic constraints provide a viable mechanism for projecting cold range boundaries and range shifts in response to climate change for endotherms.

ecology↗