Evolutionary drivers of the hump-shaped latitudinal gradient of benthic polychaete species richness along the Southeastern Pacific coast

作者：Rodrigo A. Moreno, Fabio A. Labra, Darko D. Cotoras, Patricio A. Camus, Dimitri Gutiérrez, Luis Aguirre, Nicolás Rozbaczylo, Élie Poulin, Nelson A. Lagos, Daniel Zamorano, Marcelo M. Rivadeneira · 发表于：PeerJ · 年份：2021 · DOI：10.7717/peerj.12010 · 被引用次数：16 · 研究领域：Marine Biology and Ecology Research、Isotope Analysis in Ecology、Species Distribution and Climate Change

Latitudinal diversity gradients (LDG) and their explanatory factors are among the most challenging topics in macroecology and biogeography. Despite of its apparent generality, a growing body of evidence shows that ‘anomalous’ LDG ( i.e ., inverse or hump-shaped trends) are common among marine organisms along the Southeastern Pacific (SEP) coast. Here, we evaluate the shape of the LDG of marine benthic polychaetes and its underlying causes using a dataset of 643 species inhabiting the continental shelf (<200 m depth), using latitudinal bands with a spatial resolution of 0.5°, along the SEP (3–56° S). The explanatory value of six oceanographic (Sea Surface Temperature (SST), SST range, salinity, salinity range, primary productivity and shelf area), and one macroecological proxy (median latitudinal range of species) were assessed using a random forest model. The taxonomic structure was used to estimate the degree of niche conservatism of predictor variables and to estimate latitudinal trends in phylogenetic diversity, based on three indices (phylogenetic richness (PD SES ), mean pairwise distance (MPD SES ), and variation of pairwise distances (VPD)). The LDG exhibits a hump-shaped trend, with a maximum peak of species richness at ca. 42° S, declining towards northern and southern areas of SEP. The latitudinal pattern was also evident in local samples controlled by sampling effort. The random forest model had a high accuracy (pseudo-r 2 = 0.95) and showed that the LDG could b...