Wright T F, Wilkinson G S
Department of Biology, University of Maryland, College Park 20742, USA.
Proc Biol Sci. 2001 Mar 22;268(1467):609-16. doi: 10.1098/rspb.2000.1403.
The relationship between cultural and genetic evolution was examined in the yellow-naped amazon Amazona auropalliata. This species has previously been shown to have regional dialects defined by large shifts in the acoustic structure of its learned contact call. Mitochondrial DNA sequence variation from a 680 base pair segment of the first domain of the control region was assayed in 41 samples collected from two neighbouring dialects in Costa Rica. The relationship of genetic variation to vocal variation was examined using haplotype analysis, genetic distance analysis, a maximum-likelihood estimator of migration rates and phylogenetic reconstructions. All analyses indicated a high degree of gene flow and, thus, individual dispersal across dialect boundaries. Calls sampled from sound libraries suggested that temporally stable contact call dialects occur throughout the range of the yellow-naped amazon, while the presence of similar dialects in the sister species Amazona ochrocephala suggests that the propensity to form dialects is ancestral in this clade. These results indicate that genes and culture are not closely associated in the yellow-naped amazon. Rather, they suggest that regional diversity in vocalizations is maintained by selective pressures that promote social learning and allow individual repertoires to conform to local call types.
研究了黄颈亚马逊鹦鹉（Amazona auropalliata）文化与基因进化之间的关系。此前已证明该物种具有由其习得的联络叫声声学结构的大幅变化所定义的区域方言。在从哥斯达黎加两个相邻方言中采集的41个样本中，对控制区第一结构域680个碱基对片段的线粒体DNA序列变异进行了分析。使用单倍型分析、遗传距离分析、迁移率的最大似然估计器和系统发育重建来研究遗传变异与声音变异之间的关系。所有分析均表明存在高度的基因流动，因此个体在方言边界间扩散。从声音库中采样的叫声表明，在黄颈亚马逊鹦鹉的整个分布范围内都存在时间上稳定的联络叫声方言，而在姊妹物种黄冠亚马逊鹦鹉（Amazona ochrocephala）中也存在类似方言，这表明形成方言的倾向在该进化枝中是祖传的。这些结果表明，在黄颈亚马逊鹦鹉中基因与文化没有紧密关联。相反，它们表明发声的区域多样性是由促进社会学习并允许个体发音符合当地叫声类型的选择压力所维持的。
