Genomic Evidence for Rare Hybridization and Large Demographic Changes in the Evolutionary Histories of Four North American Dove Species

Introductions and invasions provide opportunities for interaction and hybridization between colonists and closely related native species. We investigate this phenomenon using the mitochondrial DNA COI and 81,416 base-pairs of overlapping nuclear variation to examine the evolutionary histories and signatures of hybridization among introduced feral Rock Pigeon and Eurasian Collared-Dove and native White-winged and Mourning doves in southwestern North America. First, we report all four species to be highly divergent across loci (overall pair-wise species ΦST range = 0.17–0.70) and provide little evidence for gene flow at evolutionary timescales. Despite this, evidence from multiple population genetics analyses supports the presence of six putative contemporary late-stage hybrids among the 182 sampled individuals. These putative hybrids contain various ancestry combinations, but all involve the most populous species, the Mourning Dove. Next, we use a novel method to reconstruct demographic changes through time using partial genome sequence data. We identify recent, species-specific fluctuations in population size that are likely associated with changing environments since the Miocene and suggest that these fluctuations have influenced the genetic diversity of each dove species in ways that may impact their future persistence. Finally, we discuss the importance of using multiple marker types when attempting to infer complex evolutionary histories and propose important considerations when analyzing populations that were recently established or of domestic origins.

Diet-related Physiological Plasticity of Mourning Doves: A Metabolomic Approach (P09-002-19)

Objectives As birds are a natural model of diabetes, the objective of this study was to test the hypothesis that feeding adult mourning doves, Zenaida macroura, a high fat diet (60% calories from fat; HF) or refined carbohydrate diet (white bread: WB) for four weeks results in diabetes-like pathologies including hyperglycemia and altered metabolic profiles. Methods Separate cohorts of doves were captured for each feeding trial and were acclimated for one week to their respective study diets; cohort 1: WB (n = 6) vs nutritionally-balanced seeds (n = 6), and cohort 2: HF (n = 4) vs control (n = 6). The WB study mimicked natural feeding options for wild birds whereas the HF study used experimental diets. Four weeks later, birds were euthanized with an overdose of sodium pentobarbital and we collected cardiac blood, liver, kidney (HF study only), and pectoralis muscle for metabolomic analyses and biochemical assays. Results Pathway analysis of metabolic concentrations revealed only two pathways that were significantly altered (p < 0.05) and concurrently highly impacted (scale: 0-1; > 0.60) by the HF diet consumption: ubiquinone and other terpenoid-quinone biosynthesis (plasma and pectoralis muscle) and alanine, aspartate, and glutamate metabolism (plasma and kidney; p < 0.05). Only three low impact pathways were significantly affected by the WB diet consumption: glutathione metabolism and histidine metabolism (liver), and glyoxylate and dicarboxylate metabolism (pectoralis muscle; p < 0.05). Further, consumption neither of the HF nor of the WB diet altered plasma uric acid, insulin, pectoralis muscle, liver triglycerides, or body mass (only measured in HF study) significantly, but liver glycogen concentrations were 2.12-fold higher in WB than control doves (p < 0.015). Lastly, blood glucose concentrations did not differ between WB or HF birds and control birds. Conclusions Contrary to our hypothesis, consumption of a WB or HF diet for four weeks did not induce symptoms of diabetes in doves. Further elucidating the apparent avian resistance to diet-induced metabolic complications may help develop novel therapeutic agents for mammalian diabetes. Funding Sources ASU School of Life Sciences/Office of Knowledge Enterprise Development - Research Investment Initiative, a summer research fellowship from the American Physiology Society, and the Center of Evolution and Medicine Graduate Fellow Award.