Invasion History and Mitogenome Evolution of a Successful Avian Invader

Invasive species constitute powerful models for investigating adaptations underpinning successful range expansion. Invasion into the new environments is associated with diverse bioenergetic demands and therefore can induce metabolic adaptations. An excellent example of the invasive species that occupies diverse habitats is a common house crow (Corvus splendens), which originates from Indian subcontinent but has been successfully spreading throughout various environments in Asia and Africa and more recently in Europe. In this study we aim to trace colonization history and to investigate if metabolic adaptations from standing genetic variation could be involved in the success of recent invasions by a house crow. To do that, we constructed a Bayesian dated phylogeny based on 13 mitochondrial protein coding genes of house crows sampled from diverse habitats within native and invasive ranges. Results supported mid-Pleistocene (683 thousand years ago) divergence between most distant lineages. Phylogeographic patterns suggest South Asia as a species radiation centre. Codon based and amino acid properties analyses provide evidence of widespread purifying selection across mitochondrial genome and signatures positive selection acting on four amino acids of two NADH dehydrogenase genes (ND2 and ND5). Most mutations were fixed within native range lineages originating from tropical and warm temperate climates. One mutation (Thr to Ala in the codon 126 of ND5) was specific to the temperate climate population in South Africa. We suggest emergence of lineages adapted to withstand harsh environmental conditions within native range and their subsequent spread to what we currently consider species’ invasive range.