Data from: Genetic, morphological and acoustic evidence reveals lack of diversification in the colonization process in an island bird

Songbirds with recently (i.e. early Holocene) founded populations are
suitable models for studying incipient differentiation in oceanic islands.
On such systems each colonization event represents a different
evolutionary episode that can be studied by addressing sets of diverging
phenotypic and genetic traits. We investigate the process of early
differentiation in the spectacled warbler (Sylvia conspicillata) in 14
populations separated by sea barriers from three Atlantic archipelagos and
from continental regions spanning from tropical to temperate latitudes.
Our approach involved the study of sexual acoustic signals, morphology and
genetic data. Mitochondrial DNA did not provide clear population
structure. However, microsatellites analyses consistently identified two
genetic groups, albeit without correspondence to subspecies classification
and little correspondence to geography. Coalescent analyses showed
significant evidence for gene flow between the two genetic groups.
Discriminant analyses could not correctly assign morphological or acoustic
traits to source populations. Therefore, although theory predicting that
in isolated populations genetic, morphological or acoustic traits can lead
to radiation, we have strikingly failed to document differentiation on
these attributes in a resident passerine throughout three oceanic
archipelagos.

近期（即全新世早期）形成种群的鸣禽，是研究大洋岛屿物种初期分化的适宜模型。在此类系统中，每一次定殖事件均代表一次独立的演化进程，可通过分析一系列趋异的表型与遗传性状开展研究。本研究以眼镜林莺（Sylvia conspicillata）为研究对象，探究其14个被海洋屏障分隔的种群的初期分化进程，这些种群分布于3个大西洋群岛以及横跨热带至温带纬度带的大陆区域。本研究的分析方法涵盖性声学信号、形态学特征及遗传学数据的检测与分析。线粒体DNA（mitochondrial DNA）未能揭示清晰的种群遗传结构。然而，微卫星标记（microsatellites）分析始终识别出两个遗传类群，尽管该结果与亚种分类几乎无对应关系，且与地理分布的契合度也极低。溯祖分析（coalescent analyses）结果表明，这两个遗传类群间存在显著的基因交流。判别分析（discriminant analyses）无法将形态学特征或声学信号准确匹配至其来源种群。因此，尽管现有理论预测隔离种群的遗传、形态学或声学特征可推动适应辐射，但本研究却出人意料地发现，在横跨3个大洋群岛的居留性雀形目鸟类（passerine）中，并未观测到上述特征存在分化的证据。

搜集汇总

背景与挑战

背景概述

该数据集包含大西洋群岛鸟类（Sylvia conspicillata）的微卫星基因型、标准化声学特征和形态特征数据，用于研究岛屿殖民过程中的早期分化现象。研究发现种群间在遗传、形态和声学特征上均未形成显著分化，表明基因流可能阻碍了分化进程。