Data from: Uncertainty in geographic estimates of performance and fitness

1. Thermal performance curves (TPCs) have become key tools for predicting geographic distributions of performance by ectotherms. Such TPC-based predictions, however, may be sensitive to errors arising from diverse sources.
2. We analyzed potential errors that arise from common choices faced by biologists integrating TPCs with climate data by constructing case studies focusing on experimental sets of TPCs and simulating geographic patterns of mean performance. We first analyzed differences in geographic patterns of performance derived from two pairs of commonly used TPCs. Mean performance differed most (up to 30%) in regions with relatively constant mean temperatures similar to those at which the TPCs diverged the most.
3. We also analyzed the effects of thermal history by comparing geographic estimates derived from (1) a broad TPC based on short-term measurements of insect larvae (Manduca sexta) with a history of exposure to thermal variation versus (2) a narrow TPC based on long-term measurements of larvae held at constant temperatures. Estimated mean performance diverged by up to 40%, and differences were magnified in simulated future climates.
4. Finally, to quantify geographic error arising from statistical error in fitted TPCs, we propose and illustrate a bootstrapping technique for establishing 95% prediction intervals on mean performance at each location (pixel).
5. Collectively, our analyses indicate that error arising from several underappreciated sources can significantly affect the mean performance values derived from TPCs, and we suggest that the magnitudes of these errors should be estimated routinely in future studies.

1. 热性能曲线（Thermal performance curves, TPCs）现已成为预测外温动物（ectotherms）性能地理分布的核心工具。然而，这类基于TPC的预测可能对多种来源的误差十分敏感。
2. 本研究通过聚焦TPC实验集的案例研究，并模拟平均性能的地理格局，分析了生物学家在将TPC与气候数据整合时所面临的常见选择所引发的潜在误差。我们首先分析了由两组常用TPC推导得到的性能地理格局之间的差异。在平均温度相对恒定、且与TPC差异最大的温度区间相近的区域，平均性能的差异最为显著（最高可达30%）。
3. 我们还通过对比两种方式得到的地理估算结果，分析了热历史的影响：（1）基于对经历过温度波动的烟草天蛾（Manduca sexta）幼虫的短期测量所构建的宽幅TPC，以及（2）基于对在恒定温度下饲养的幼虫的长期测量所构建的窄幅TPC。估算得到的平均性能差异最高可达40%，且在模拟未来气候情境下，这类差异会被进一步放大。
4. 最后，为了量化由拟合TPC的统计误差所引发的地理误差，我们提出并展示了一种自举技术（bootstrapping technique），用于为每个地理位置（栅格像素，pixel）的平均性能构建95%预测区间。
5. 综合来看，我们的分析表明，多个未被充分重视的来源所引发的误差，会显著影响基于TPC推导得到的平均性能数值；我们建议在未来的研究中，应常规估算这类误差的大小。