英国雷丁大学Chris Venditti和Jorge Avaria-Llautureo等研究人员合作发现恒温进化过程中基础代谢率和体温的解耦性。相关论文2019年8月29日发表在《自然》杂志上。

研究人员发现基础代谢率（BMR）和体温（T_b）在大约90％的哺乳动物系统发育分支和36％的禽类系统发育分支中解耦。哺乳动物BMR以快速爆发式进化，但没有长期的方向性趋势，而T_b主要以恒定的速率朝着更冷的身体进化，而这来自于原本更温暖身体的祖先。禽类BMR主要以恒定速率进化而没有长期方向性趋势，而T_b以更大的速率异质性和更适应性向更冷身体进化。此外，导致BMR增加和减少的快速变化与较冷的环境温度的突然变化有关，尽管这仅在哺乳动物中观察到。这些研究结果表明，自然选择有效地利用了哺乳动物BMR在不同的、往往不利的历史热环境下的多样性。

据介绍，鸟类和哺乳动物恒温的起源是脊椎动物进化的重要事件。恒温可以在很宽的环境温度范围内维持T_b，主要是利用其高BMR连续产生的热量。由于T_b影响BMR，因此还存在重要的正反馈回路。由于BMR和T_b之间的这种相互作用，许多生态学家和进化生理学家认为BMR和T_b的演变必须在恒温辐射期间耦合，并随着类似的趋势而变化。然而，较冷的历史环境可能对BMR施加了强大的选择压力，以补偿增加的热损失率并保持T_b恒定。因此，通过增加BMR来适应寒冷的环境温度可能使BMR与T_b解耦，并产生这些性状现代多样性的不同进化途径。

附：英文原文

Title: The decoupled nature of basal metabolic rate and body temperature in endotherm evolution

Author: Jorge Avaria-Llautureo, Cristin E. Hernndez, Enrique Rodrguez-Serrano, Chris Venditti

Issue&Volume: Volume 572 Issue 7771

Abstract: The origins of endothermy in birds and mammals are important events in vertebrate evolution. Endotherms can maintain their body temperature (Tb) over a wide range of ambient temperatures primarily using the heat that is generated continuously by their high basal metabolic rate (BMR)1. There is also an important positive feedback loop as Tb influences BMR1,2,3. Owing to this interplay between BMRs and Tb, many ecologists and evolutionary physiologists posit that the evolution of BMR and Tb must have been coupled during the radiation of endotherms3,4,5, changing with similar trends6,7,8. However, colder historical environments might have imposed strong selective pressures on BMR to compensate for increased rates of heat loss and to keep Tb constant9,10,11,12. Thus, adaptation to cold ambient temperatures through increases in BMR could have decoupled BMR from Tb and caused different evolutionary routes to the modern diversity in these traits. Here we show that BMR and Tb were decoupled in approximately 90% of mammalian phylogenetic branches and 36% of avian phylogenetic branches. Mammalian BMRs evolved with rapid bursts but without a long-term directional trend, whereas Tb evolved mostly at a constant rate and towards colder bodies from a warmer-bodied common ancestor. Avian BMRs evolved predominantly at a constant rate and without a long-term directional trend, whereas Tb evolved with much greater rate heterogeneity and with adaptive evolution towards colder bodies. Furthermore, rapid shifts that lead to both increases and decreases in BMRs were linked to abrupt changes towards colder ambient temperatures—although only in mammals. Our results suggest that natural selection effectively exploited the diversity in mammalian BMRs under diverse, often-adverse historical thermal environments.

DOI: 10.1038/s41586-019-1476-9

Source:https://www.nature.com/articles/s41586-019-1476-9