Bees are also of enormous economic importance. Bees, comprising nearly 20,000 described species ( 8), and angiosperms, comprising over 250,000 described species ( 100), represent one of the most successful (and fascinating) coevolutionary partnerships on earth. They arose in the early to mid-Cretaceous approximately 140 to 110 Mya (million years ago), roughly coincident with the origins and early diversification of flowering plants. The availability of the complete honey bee genome ( 41) and a number of published bee transcriptomes ( 108) provides an opportunity for researchers to expand the range of protein-coding genes used in bee phylogeny.īees are arguably the most important group of angiosperm-pollinating insects. One of the most widely used protein-coding genes is the F2 copy of elongation factor-1α (EF-1α F2), which has been used in over 30 published bee studies ( Supplemental Table 1). Nuclear protein-coding genes provide an ideal source of data for higher-level studies because coding regions can be aligned unambiguously across a broad range of organisms ( 75). However, ribosomal genes pose serious challenges because they are difficult to align unambiguously. Nuclear ribosomal genes (18S and 28S) have been used in a variety of studies ( Supplemental Table 1). Mitochondrial genes, such as 16S, cytB, and COI and/or COII, continue to be widely used in bee phylogeny ( Supplemental Table 1), but these genes tend to have their greatest utility at lower taxonomic levels ( 52).
Early studies ( 14, 21, 47) tended to focus on mitochondrial genes because they are easy to amplify. The number of genes used to reconstruct bee phylogeny has expanded dramatically over the past 15 years. We review the phylogenetic hypotheses family-by-family and then describe how the new phylogenetic insights have altered our understanding of bee biology. In this paper, we present an overview of significant discoveries in bee phylogeny based primarily on the application of molecular data. Phylogenies have provided the comparative framework for understanding the evolution of host-plant associations and pollen specialization, the evolution of social behavior, and the evolution of parasitism. In addition, molecular phylogenies have played an important role in inferring evolutionary patterns and processes in bees. Phylogenetic studies based on single or, more commonly, multilocus data sets have helped resolve the placement of bees within the superfamily Apoidea the relationships among the seven families of bees and the relationships among bee subfamilies, tribes, genera, and species. and Chicago and is about 300 miles shorter as another option.Our understanding of bee phylogeny has improved over the past fifteen years as a result of new data, primarily nucleotide sequence data, and new methods, primarily model-based methods of phylogeny reconstruction. The Capitol Limited train also travels between Washington D.C.The Cardinal is popular in the fall with the autumn colors, so be sure to book roomettes or bedrooms in advance if that’s your preferred accommodation type.
0 kommentar(er)
