Department of Aquatic Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, Netherlands.
Department of Biology, University of Turku, Turku, Finland.
Ecology. 2023 Jan;104(1):e3853. doi: 10.1002/ecy.3853. Epub 2022 Oct 23.
The growth rate hypothesis (GRH) posits that the relative body phosphorus content of an organism is positively related to somatic growth rate, as protein synthesis, which is necessary for growth, requires P-rich rRNA. This hypothesis has strong support at the interspecific level. Here, we explore the use of the GRH to predict microevolutionary responses in consumer body stoichiometry. For this, we subjected populations of the rotifer Brachionus calyciflorus to selection for fast population growth rate (PGR) in P-rich (HPF) and P-poor (LPF) food environments. With common garden transplant experiments, we demonstrate that in HP populations evolution toward increased PGR was concomitant with an increase in relative phosphorus content. In contrast, LP populations evolved higher PGR without an increase in relative phosphorus content. We conclude that the GRH has the potential to predict microevolutionary change, but that its application is contingent on the environmental context. Our results highlight the potential of cryptic evolution in determining the performance response of populations to elemental limitation of their food resources.
生长率假说（GRH）认为，生物体的相对体磷含量与躯体生长率呈正相关，因为蛋白质合成是生长所必需的，而蛋白质合成需要富含磷的 rRNA。这一假说在种间水平得到了强有力的支持。在这里，我们探索了使用 GRH 来预测消费者体化学计量的微进化反应。为此，我们对轮虫 Brachionus calyciflorus 的种群进行了选择，以在富含磷（HPF）和贫磷（LPF）食物环境中获得快速种群增长率（PGR）。通过共同花园移植实验，我们证明在 HP 种群中，向更高 PGR 的进化伴随着相对磷含量的增加。相比之下，LP 种群在相对磷含量没有增加的情况下进化出了更高的 PGR。我们的结论是，GRH 有可能预测微进化的变化，但它的应用取决于环境背景。我们的研究结果强调了隐生进化在决定种群对食物资源元素限制的表现反应方面的潜力。
