Deng Weiye, Jin Long, Qiu Duojing, Yan Chengzhi, Liao Wenbo
Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong 637009, China.
Key Laboratory of Artificial Propagation and Utilization in Anurans of Nanchong City, China West Normal University, Nanchong 637009, China.
Animals (Basel). 2023 Aug 16;13(16):2645. doi: 10.3390/ani13162645.
Adaptive evolution is the process by which organisms change their morphological, physiological and biochemical characteristics to adapt to different environments during long-term natural selection. Especially, researching variation in organ size can provide important insights into morphological adaptation in amphibians. In this study, we comparatively studied differences in organ sizes (heart, lungs, liver, gallbladder, kidneys, spleen, digestive tract, testes and brain) among five geographical populations of the Asian common toad . Our results revealed significant variations in the size of these nine specific organs among the populations. Notably, we observed a significant positive correlation between the relative size of the testes and latitude and/or altitude. However, no correlation was found between the relative size of the heart and the length of the digestive tract with altitude across populations, respectively, contradicting Hesse's rule and the digestion theory. These findings suggest that our study does not provide substantial theoretical support for the adaptive evolution of organ size in this particular toad species, but rather contributes to the understanding of the evolution and adaptations of species' different environmental conditions. Further research is warranted to delve deeper into the factors influencing organ size in amphibian populations.
适应性进化是生物体在长期自然选择过程中改变其形态、生理和生化特征以适应不同环境的过程。特别是，研究器官大小的变化可以为两栖动物的形态适应提供重要见解。在本研究中，我们比较研究了亚洲蟾蜍五个地理种群之间器官大小（心脏、肺、肝脏、胆囊、肾脏、脾脏、消化道、睾丸和大脑）的差异。我们的结果显示，这些九个特定器官的大小在种群之间存在显著差异。值得注意的是，我们观察到睾丸的相对大小与纬度和/或海拔之间存在显著正相关。然而，在不同种群中，心脏的相对大小与消化道长度与海拔之间均未发现相关性，这与黑塞法则和消化理论相矛盾。这些发现表明，我们的研究并未为这种特定蟾蜍物种器官大小的适应性进化提供实质性的理论支持，而是有助于理解物种对不同环境条件的进化和适应。有必要进行进一步的研究，以更深入地探究影响两栖动物种群器官大小的因素。
