Llewelyn John, Macdonald Stewart L, Moritz Craig, Martins Felipe, Hatcher Amberlee, Phillips Ben L
Centre for Tropical Biodiversity and Climate Change, James Cook University, Townsville, Queensland, Australia.
CSIRO Land and Water, Townsville, Queensland, Australia.
Integr Zool. 2018 Jul;13(4):411-427. doi: 10.1111/1749-4877.12309.
The impact of climate change may be felt most keenly by tropical ectotherms. In these taxa, it is argued, thermal specialization means a given shift in temperature will have a larger effect on fitness. For species with limited dispersal ability, the impact of climate change depends on the capacity for their climate-relevant traits to shift. Such shifts can occur through genetic adaptation, various forms of plasticity, or a combination of these processes. Here we assess the extent and causes of shifts in 7 physiological traits in a tropical lizard, the rainforest sunskink (Lampropholis coggeri). Two populations were sampled that differ from each other in both climate and physiological traits. We compared trait values in each animal soon after field collection versus following acclimation to laboratory conditions. We also compared trait values between populations in: (i) recently field-collected animals; (ii) the same animals following laboratory acclimation; and (iii) the laboratory-reared offspring of these animals. Our results reveal high trait lability, driven primarily by acclimation and local adaptation. By contrast, developmental plasticity, resulting from incubation temperature, had little to no effect on most traits. These results suggest that, while specialized, tropical ectotherms may be capable of rapid shifts in climate-relevant traits.
气候变化的影响可能在热带变温动物身上体现得最为明显。在这些分类群中，有人认为，热特化意味着温度的特定变化对适合度会有更大影响。对于扩散能力有限的物种而言，气候变化的影响取决于其与气候相关的性状发生变化的能力。这种变化可以通过基因适应、各种形式的可塑性或这些过程的组合来实现。在此，我们评估了一种热带蜥蜴——雨林石龙子（Lampropholis coggeri）的7种生理性状变化的程度和原因。我们对两个在气候和生理性状上都存在差异的种群进行了采样。我们比较了每只动物在野外采集后不久以及适应实验室条件后的性状值。我们还比较了以下几种情况下种群之间的性状值：（i）最近野外采集的动物；（ii）经过实验室适应后的同一批动物；以及（iii）这些动物在实验室饲养的后代。我们的结果显示出高性状可塑性，这主要是由适应和局部适应驱动的。相比之下，由孵化温度导致的发育可塑性对大多数性状几乎没有影响。这些结果表明，虽然热带变温动物具有特殊性，但它们可能有能力在与气候相关的性状上迅速发生变化。
