Mixed phylogenetic signal in fish toxicity data across chemical classes.

Andrew Hylton,Ylenia Chiari,Mace G Barron,Isabella Capellini,Scott Glaberman

doi:10.1002/eap.1698

Abstract

Chemical use in society is growing rapidly and is one of the five major pressures on biodiversity worldwide. Since empirical toxicity studies of pollutants generally focus on a handful of model organisms, reliable approaches are needed to assess sensitivity to chemicals across the wide variety of species in the environment. Phylogenetic comparative methods (PCM) offer a promising approach for toxicity extrapolation incorporating known evolutionary relationships among species. If phylogenetic signal in toxicity data is high, i.e., closely related species are more similarly sensitive as compared to distantly related species, PCM could ultimately help predict species sensitivity when toxicity data are lacking. Here, we present the largest ever test of phylogenetic signal in toxicity data by combining phylogenetic data from fish with acute mortality data for 42 chemicals spanning 10 different chemical classes. Phylogenetic signal is high for some chemicals, particularly organophosphate pesticides, but not necessarily for many chemicals in other classes (e.g., metals, organochlorines). These results demonstrate that PCM may be useful for toxicity extrapolation in untested species for those chemicals with clear phylogenetic signal. This study provides a framework for using PCM to understand the patterns and causes of variation in species sensitivity to pollutants.

Highlights

The number of chemicals manufactured and released into the environment has grown rapidly, with an estimated 85,000 and 100,000 chemicals registered commercially in the United States (U.S EPA 2017a) and Europe (Schwarzenbach et al 2006), respectively
Chiari et al (2015) show that there is strong phylogenetic signal in species sensitivity to copper sulfate in amphibians, and that temperature explains more of the variation in acute mortality once phylogeny has been accounted for using Phylogenetic comparative methods (PCM)
Regardless of whether we include experimental temperature, the phylogenetic signal is significantly >0 for 10 of the 42 chemicals examined

Summary

Introduction

The number of chemicals manufactured and released into the environment has grown rapidly, with an estimated 85,000 and 100,000 chemicals registered commercially in the United States (U.S EPA 2017a) and Europe (Schwarzenbach et al 2006), respectively. PCM can help explain both patterns of species phenotypic values given their phylogenetic relationships and incorporate phylogenetic relationships into statistical models when investigating the effect of different explanatory factors (e.g., ecology, life history, morphology) on these same phenotypic values (Felsenstein 1985, Harvey and Pagel 1991, Pagel 1999, Freckleton et al 2002).

Results

Conclusion