Department of Bioinformatics and Genetics, Swedish Museum of Natural History, PO Box 50007, SE-104 05 Stockholm, Sweden.
School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia.
Syst Biol. 2020 Sep 1;69(5):820-829. doi: 10.1093/sysbio/syaa040.
The bowerbirds in New Guinea and Australia include species that build the largest and perhaps most elaborately decorated constructions outside of humans. The males use these courtship bowers, along with their displays, to attract females. In these species, the mating system is polygynous and the females alone incubate and feed the nestlings. The bowerbirds also include 10 species of the socially monogamous catbirds in which the male participates in most aspects of raising the young. How the bower-building behavior evolved has remained poorly understood, as no comprehensive phylogeny exists for the family. It has been assumed that the monogamous catbird clade is sister to all polygynous species. We here test this hypothesis using a newly developed pipeline for obtaining homologous alignments of thousands of exonic and intronic regions from genomic data to build a phylogeny. Our well-supported species tree shows that the polygynous, bower-building species are not monophyletic. The result suggests either that bower-building behavior is an ancestral condition in the family that was secondarily lost in the catbirds, or that it has arisen in parallel in two lineages of bowerbirds. We favor the latter hypothesis based on an ancestral character reconstruction showing that polygyny but not bower-building is ancestral in bowerbirds, and on the observation that Scenopoeetes dentirostris, the sister species to one of the bower-building clades, does not build a proper bower but constructs a court for male display. This species is also sexually monomorphic in plumage despite having a polygynous mating system. We argue that the relatively stable tropical and subtropical forest environment in combination with low predator pressure and rich food access (mostly fruit) facilitated the evolution of these unique life-history traits. [Adaptive radiation; bowerbirds; mating system, sexual selection; whole genome sequencing.].
新几内亚和澳大利亚的园丁鸟包括一些物种，它们建造的求偶亭是除人类以外最大、可能也是最精心装饰的建筑。雄鸟用这些求偶亭和它们的表演来吸引雌鸟。在这些物种中，交配系统是多配偶制的，只有雌鸟孵化和喂养雏鸟。园丁鸟还包括 10 种社会一夫一妻制的猫鸟，其中雄性参与抚养幼鸟的大部分方面。由于该科没有一个全面的系统发育，因此，筑巢行为是如何进化的仍然知之甚少。人们一直认为，一夫一妻制的猫鸟分支与所有多配偶制的物种是姐妹关系。我们在这里使用一个新开发的管道来获取来自基因组数据的数千个外显子和内含子区域的同源比对，以构建一个系统发育。我们得到的支持良好的物种树表明，多配偶制、筑巢的物种不是单系的。这一结果表明，筑巢行为要么是该科的一个祖先特征，后来在猫鸟中丢失了，要么是在两个园丁鸟谱系中平行出现的。我们倾向于后一种假说，基于一个祖先特征重建，表明多配偶制而不是筑巢是园丁鸟的祖先特征，并且观察到 Scenopoeetes dentirostris，与一个筑巢分支的姐妹物种，没有建造一个合适的亭，但为雄性展示建造了一个庭院。尽管这种物种的交配系统是多配偶制，但它在羽毛上也是两性同态的。我们认为，相对稳定的热带和亚热带森林环境，加上低捕食压力和丰富的食物供应（主要是水果），促进了这些独特的生活史特征的进化。[适应辐射；园丁鸟；交配系统，性选择；全基因组测序。]
