Domestication obscures genomic estimates of population history.

Domesticated species are valuable models to examine phenotypic evolution, and knowledge on domestication history is critical for understanding the trajectories of evolutionary changes. Sequentially Markov Coalescent models are often used to infer domestication history. However, domestication practices may obscure the signal left by population history, affecting demographic inference. Here we assembled the genomes of a recently domesticated species-the society finch-and its parent species-the white-rumped munia-to examine its domestication history. We applied genomic analyses to two society finch breeds and white-rumped munias to test whether domestication of the former resulted from inbreeding or hybridization. The society finch showed longer and more runs of homozygosity and lower genomic heterozygosity than the white-rumped munia, supporting an inbreeding origin in the former. Blocks of white-rumped munia and other ancestry in society finch genomes showed similar genetic distance between the two taxa, inconsistent with the hybridization origin hypothesis. We then applied two Sequentially Markov Coalescent models-psmc and smc++-to infer the demographic histories of both. Surprisingly, the two models did not reveal a recent population bottleneck, but instead the psmc model showed a specious, dramatic population increase in the society finch. Subsequently, we used simulated genomes based on an array of demographic scenarios to demonstrate that recent inbreeding, not hybridization, caused the distorted psmc population trajectory. Such analyses could have misled our understanding of the domestication process. Our findings stress caution when interpreting the histories of recently domesticated species inferred by psmc, arguing that these histories require multiple analyses to validate.

ALFAXALONE ANESTHESIA IN THE BENGALESE FINCH ( LONCHURA DOMESTICA).

The objective of this study was to evaluate the use of alfaxalone in a small passerine species. A dose-response trial was conducted whereby 10, 30, and 50 mg/kg alfaxalone was administered subcutaneously (SC) to 10 Bengalese finches ( Lonchura domestica) in a randomized complete crossover study design. Subsequently, a similar protocol was used to compare 30 mg/kg alfaxalone alone or combined with either 0.7 mg/kg midazolam or 1 mg/kg butorphanol SC. Induction and recovery times were recorded and depth of anesthesia monitored at 5-min intervals throughout each procedure. Functional oxygen saturation and pulse rates were measured with a pulse oximeter at 15 min after administration of the anesthetic agent(s). Dose-dependent decreases in induction time and prolongation of anesthetic duration were seen with increasing alfaxalone dosage. Alfaxalone combined with midazolam resulted in faster inductions, and the addition of both midazolam and butorphanol resulted in longer durations of anesthesia than alfaxalone alone. The addition of midazolam significantly decreased the pulse rate at 15 min compared with alfaxalone alone. Alfaxalone was found to be an effective agent for inducing anesthesia when administered subcutaneously, and no complications were observed. Increasing the dose, and combining with a benzodiazepine or opioid increased the duration of anesthesia with minimal or no effects on respiratory or pulse rates, within the dose range investigated.