| 英文摘要: | Species are the basic units of taxonomy, playing an important role in scientific communication and environmental policy. While the theoretical understanding of the species concept has advanced greatly, methodologies for the objective delimitation of species remain inefficient. This study by researchers at the University of Wisconsin - Madison and Iowa State University will develop new computational tools to make species delimitation more efficient. Their research will also address a central question in biology: What is a species? This study will use the genus Adansonia (the baobabs) as a testing ground for these methods. Baobabs are iconic trees of great cultural, ecological, and economic importance in Madagascar, continental Africa, and northwestern Australia, and are also a microcosm for many of the challenges that arise in species delimitation. The work will train undergraduate researchers, K-12 teachers, graduate students, and a postdoctoral associate at the interface of taxonomy, genomics, and computational statistics and provide several opportunities to establish international collaboration. Together, this research will provide new insights into Adansonia systematics and provide a new framework to facilitate species delimitation in diverse groups.
Species delimitation encompasses diverse methods that use genetic, morphological and other trait data to guide taxonomic grouping (placing organisms in hierarchically nested taxa) and ranking (deciding where taxa sit relative to the transition from tree-like relationships at higher levels to reticulate genealogies within populations). Species delimitation remains challenging in many groups due to polyploidy, introgression, and/or species with complex geographic patterns of morphological variation. However, opportunities for progress are offered by recent advances in high throughput sequencing technologies that facilitate rapid acquisition of multilocus DNA sequence data, and by new analytical methods for species level taxonomic problems. Using baobabs as a model, this study will develop a rapid and efficient experimental protocol using sequence capture technology and next-generation sequencing that will allow the application of different species delimitation methods. In addition to deploying existing analytical methods, the researchers will extend the Bayesian Phylogenetics and Phylogeography (BPP) method to formally incorporate morphology and geography. Further, they will add capability to the software program BUCKy for identifying cases where the data imply hybridization or introgression that could be applied in diverse groups of organisms. |