Department of Biology, University of Washington, Seattle, WA, 98125, USA.
School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA.
Glob Chang Biol. 2017 Mar;23(3):1075-1084. doi: 10.1111/gcb.13476. Epub 2016 Sep 9.
Although observations suggest the potential for phenotypic plasticity to allow adaptive responses to climate change, few experiments have assessed that potential. Modeling suggests that Sceloporus tristichus lizards will need increased nest depth, shade cover, or embryonic thermal tolerance to avoid reproductive failure resulting from climate change. To test for such plasticity, we experimentally examined how maternal temperatures affect nesting behavior and embryonic thermal sensitivity. The temperature regime that females experienced while gravid did not affect nesting behavior, but warmer temperatures at the time of nesting reduced nest depth. Additionally, embryos from heat-stressed mothers displayed increased sensitivity to high-temperature exposure. Simulations suggest that critically low temperatures, rather than high temperatures, historically limit development of our study population. Thus, the plasticity needed to buffer this population has not been under selection. Plasticity will likely fail to compensate for ongoing climate change when such change results in novel stressors.
虽然观察结果表明，表型可塑性有可能使生物对气候变化做出适应性反应，但很少有实验评估这种可能性。建模表明，三色石龙子蜥蜴将需要增加巢深、遮荫或胚胎热耐受能力，以避免因气候变化而导致繁殖失败。为了测试这种可塑性，我们进行了实验，研究了母体温度如何影响筑巢行为和胚胎热敏感性。雌性在怀孕期间经历的温度条件不会影响筑巢行为，但筑巢时的较高温度会降低巢深。此外，来自受热母亲的胚胎对高温暴露表现出更高的敏感性。模拟表明，历史上限制我们研究种群发育的是临界低温，而不是高温。因此，缓冲该种群所需的可塑性尚未得到选择。当这种变化导致新的压力源时，可塑性很可能无法弥补正在发生的气候变化。
