Rates of molecular evolution and genetic diversity in European vs. North American populations of invasive insect species

Sarah J. ADAMOWICZ,Tzitziki LOEZA-QUINTANA,T. Fatima MITTERBOECK,Robert G. YOUNG

doi:10.14411/eje.2018.071

Abstract

Many factors contribute to the 'invasive potential' of species or populations. It has been suggested that the rate of genetic evolution of a species and the amount of genetic diversity upon which selection can act may play a role in invasiveness. In this study, we examine whether invasive species have a higher relative pace of molecular evolution as compared with closely related non-invasive species, as well as examine the genetic diversity between invasive and closely related species. To do this, we used mitochondrial cytochrome c oxidase subunit I sequences of 35 species with a European native range that are invasive in North America. Unique to molecular rate studies, we permuted across sequences when comparing each invasive species with its sister clade species, incorporating a range of recorded genetic variation within species using 405,765 total combinations of invasive, sister, and outgroup sequences. We observed no significant trend in relative molecular rates between invasive and non-invasive sister clade species, nor in intraspecific genetic diversity, suggesting that differences in invasive status between closely related lineages are not strongly determined by the relative overall pace of genetic evolution or molecular genetic diversity. We support previous observations of more often higher genetic diversity in native than invaded ranges using available data for this genetic region.

Highlights

Non-native species are of large concern to natural ecosystems and can have drastic negative impacts on the native flora and fauna if they become established
The range in relative substitution rates was larger for European data points than North American data points, with 22 out of the 31 comparisons with data from both regions having a larger range of relative substitution rates for the European data
The North American sequences did not have consistently higher relative rates than European sequences (Fig. 1C represented by relative position of European [EU] and North American [NA] region bars in Fig. 3A), which suggests rates were not increased as a consequence of invasion

Summary

Introduction

Non-native species are of large concern to natural ecosystems and can have drastic negative impacts on the native flora and fauna if they become established. An introduced species is considered invasive when it can survive introduction, establish a population, and spread or have the potential to spread further in the introduced range (Richardson et al, 2000; Blackburn et al, 2011). While it can be argued that anthropogenic factors, such as the movement of organisms across vast distances by human-mediated transportation routes, have been largely responsible for the global distribution of non-native species (Lindroth, 1957; Lockwood et al, 2005), organismal traits such as the rate of dispersal and mode of reproduction play a role in the success of non-native species (Moravcová et al, 2015)

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