干旱区生态环境知识资源中心(Arid): The demographic and ecological factors shaping diversification among rare Astragalus species

Arid

DOI	10.1111/ddi.13288
	The demographic and ecological factors shaping diversification among rare Astragalus species
	Jones, Matthew R.; Winkler, Daniel E.; Massatti, Rob
通讯作者	Massatti, R (corresponding author), US Geol Survey, Southwest Biol Sci Ctr, Flagstaff, AZ 86001 USA.
来源期刊	DIVERSITY AND DISTRIBUTIONS
ISSN	1366-9516
EISSN	1472-4642
出版年	2021
英文摘要	Aim Evolutionary radiations are central to the origin and maintenance of biodiversity, yet we rarely understand how they are jointly shaped by demography and ecological opportunity. Astragalus is the largest plant genus in the world and is disproportionately comprised of rare species restricted to narrow geographic and ecological regions. Here, we explored the demographic and ecological mechanisms underlying patterns of diversification in a threatened Astragalus species complex endemic to a small desert region in the western United States. Location Southeast Utah, USA. Methods We used high-throughput DNA sequencing to infer genetic structure, genetic diversity, and demographic history (i.e., the timing of population divergence, effective population sizes and gene flow) among Astragalus taxa. We performed landscape genetic analyses to quantify the relationships between genetic differentiation, geographic distance, and ecological distance based on bioclimatic and soil variables. Finally, we identified putative adaptive loci that show higher genetic differentiation between taxa than expected based on our inferred neutral demographic model. Results We found evidence of low gene flow between three highly differentiated taxa (currently delineated as A. iselyi, A. sabulosus var. sabulosus and A. sabulosus var. vehiculus) that rapidly diverged from a small ancestral population near the beginning of the last glacial period. Genomic signatures revealed long-term effective population sizes are 2-10x larger than recent census sizes, perhaps due to the maintenance of standing genetic variation through seed banks. Consistent with limited dispersal and local adaptation, genome-wide patterns of differentiation are shaped by geographic distance (isolation-by-distance) and climate and soil variation (isolation-by-environment). Taxon-specific adaptation is further supported by uncovering putative adaptive loci. Main Conclusions Our findings suggest that interactions between demography (i.e., dispersal limitations and seeds banks) and ecological opportunity (i.e., spatial and temporal environmental heterogeneity) may promote diversification, endemism, and rarity among closely related Astragalus species and similar plant clades distributed across complex landscapes.
英文关键词	conservation environmental change glaciation natural selection Pleistocene population genetics speciation
类型	Article ; Early Access
语种	英语
开放获取类型	DOAJ Gold
收录类别	SCI-E
WOS记录号	WOS:000647406700001
WOS类目	Biodiversity Conservation ; Ecology
WOS研究方向	Biodiversity & Conservation ; Environmental Sciences & Ecology
来源机构	United States Geological Survey
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/352119
作者单位	[Jones, Matthew R.; Massatti, Rob] US Geol Survey, Southwest Biol Sci Ctr, Flagstaff, AZ 86001 USA; [Winkler, Daniel E.] US Geol Survey, Southwest Biol Sci Ctr, Moab, UT USA
推荐引用方式 GB/T 7714	Jones, Matthew R.,Winkler, Daniel E.,Massatti, Rob. The demographic and ecological factors shaping diversification among rare Astragalus species[J]. United States Geological Survey,2021.
APA	Jones, Matthew R.,Winkler, Daniel E.,&Massatti, Rob.(2021).The demographic and ecological factors shaping diversification among rare Astragalus species.DIVERSITY AND DISTRIBUTIONS.
MLA	Jones, Matthew R.,et al."The demographic and ecological factors shaping diversification among rare Astragalus species".DIVERSITY AND DISTRIBUTIONS (2021).