Fuchs Jérôme, Johnson Jeff A, Mindell David P
Department of Ornithology and Mammalogy, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, United States; UMR7205, Institut de Systématique, Evolution, Biodiversité, CNRS MNHN UPMC EPHE, Département Systématique et Evolution, Muséum National d'Histoire Naturelle, 57 Rue cuvier, Case Postale 51, F-75231 Paris Cedex 05, France; UMS MNHN/CNRS 2700, Outils et Méthodes de la Systématique Intégrative (OMSI), Muséum National d'Histoire Naturelle, 57 rue Cuvier, F-75231 Paris Cedex 05, France.
Department of Biological Sciences, Institute of Applied Sciences, University of North Texas, 1155 Union Circle #310559, Denton, TX 76203, United States.
Mol Phylogenet Evol. 2015 Jan;82 Pt A:166-82. doi: 10.1016/j.ympev.2014.08.010. Epub 2014 Sep 23.
Understanding how and why lineages diversify is central to understanding the origins of biological diversity. The avian family Falconidae (caracaras, forest-falcons, falcons) has an uneven distribution of species among multiple well-supported clades, and provides a useful system for testing hypotheses about diversification rate and correlation with environmental changes. We analyzed eight independent loci for 1-7 individuals from each of the 64 currently recognized Falconidae species, together with two fossil falconid temporal calibrations, to assess phylogeny, absolute divergence times and potential shifts in diversification rate. Our analyses supported similar diversification ages in the Early to Middle Miocene for the three traditional subfamilies, Herpetotherinae, Polyborinae and Falconinae. We estimated that divergences within the subfamily Falconinae began about 16mya and divergences within the most species-rich genus, Falco, including about 60% of all Falconidae species, began about 7.5mya. We found evidence for a significant increase in diversification rate at the basal phylogenetic node for the genus Falco, and the timing for this rate shift correlates generally with expansion of C4 grasslands beginning around the Miocene/Pliocene transition. Concomitantly, Falco lineages that are distributed primarily in grassland or savannah habitats, as opposed to woodlands, and exhibit migratory, as opposed to sedentary, behavior experienced a higher diversification rate.
理解谱系如何以及为何多样化是理解生物多样性起源的核心。隼科（凤头卡拉鹰、林隼、隼）在多个得到充分支持的进化枝中的物种分布不均，为检验关于多样化速率以及与环境变化相关性的假说提供了一个有用的系统。我们分析了64种目前已确认的隼科物种中每种1至7个个体的8个独立基因座，并结合两个隼科化石的时间校准，以评估系统发育、绝对分歧时间和多样化速率的潜在变化。我们的分析支持了三个传统亚科——蛇鹫亚科、凤头卡拉鹰亚科和隼亚科在中新世早期到中期具有相似的多样化时代。我们估计，隼亚科内的分歧始于约1600万年前，而在物种最丰富的属——隼属（包括约60%的所有隼科物种）内的分歧始于约750万年前。我们发现有证据表明隼属基部系统发育节点的多样化速率显著增加，并且这一速率变化的时间总体上与始于中新世/上新世过渡时期的C4草原扩张相关。与此同时，主要分布在草原或稀树草原栖息地而非林地、表现出迁徙而非定居行为的隼属谱系经历了更高的多样化速率。
