Chick Lacy D, Waters James S, Diamond Sarah E
Department of Biology Case Western Reserve University Cleveland OH USA.
Hawken School Gates Mills OH USA.
Evol Appl. 2020 Sep 25;14(1):36-52. doi: 10.1111/eva.13083. eCollection 2021 Jan.
Metabolic rates of ectotherms are expected to increase with global trends of climatic warming. But the potential for rapid, compensatory evolution of lower metabolic rate in response to rising temperatures is only starting to be explored. Here, we explored rapid evolution of metabolic rate and locomotor performance in acorn-dwelling ants () in response to urban heat island effects. We reared ant colonies within a laboratory common garden (25°C) to generate a laboratory-born cohort of workers and tested their acute plastic responses to temperature. Contrary to expectations, urban ants exhibited a higher metabolic rate compared with rural ants when tested at 25°C, suggesting a potentially maladaptive evolutionary response to urbanization. Urban and rural ants had similar metabolic rates when tested at 38°C, as a consequence of a diminished plastic response of the urban ants. Locomotor performance also evolved such that the running speed of urban ants was faster than rural ants under warmer test temperatures (32°C and 42°C) but slower under a cooler test temperature (22°C). The resulting specialist-generalist trade-off and higher thermal optimum for locomotor performance might compensate for evolved increases in metabolic rate by allowing workers to more quickly scout and retrieve resources.
变温动物的代谢率预计会随着全球气候变暖的趋势而增加。但随着温度升高，代谢率快速代偿性降低的潜在进化能力才刚刚开始被探索。在此，我们研究了橡果蚁（）对城市热岛效应的响应中代谢率和运动表现的快速进化。我们在实验室共同环境（25°C）中饲养蚁群，以培育出一批实验室出生的工蚁，并测试它们对温度的急性可塑性反应。与预期相反，在25°C测试时，城市蚂蚁的代谢率高于农村蚂蚁，这表明对城市化可能存在适应不良的进化反应。由于城市蚂蚁的可塑性反应减弱，在38°C测试时，城市和农村蚂蚁的代谢率相似。运动表现也发生了进化，使得城市蚂蚁在较温暖的测试温度（32°C和42°C）下的奔跑速度比农村蚂蚁快，但在较凉爽的测试温度（22°C）下则较慢。由此产生的专家 - 通才权衡以及运动表现更高的热最适温度，可能通过使工蚁能够更快地搜寻和获取资源来补偿代谢率的进化增加。
