SG: Fossils, fruits, and seeds: an integrative approach to estimating a timetree for the nightshades

从陆地入侵到花的起源，重建进化事件的时间依赖于化石记录中的证据。对于许多生物体群体来说，可用的化石很少或描述得很差，导致对何时发生重大进化转变的不确定性。这个项目将扩大关于化石记录的知识，并估计一个大型的、具有重要经济意义的植物群--夜来香的进化时间表。这个近3000个物种的家族包括许多农作物，如西红柿、土豆和烟草，但在化石记录中只有少数被描述的标本。研究人员将对推测的茄科植物化石进行调查，并使用形态和统计分析来确定它们在该家族进化史上的位置。在这个过程中，研究人员将能够估计重大进化变化的时间，例如肉质水果的起源和全基因组复制。了解这一进化史是作物改良的基础，作物改良依赖于数百万年来通过多样化积累的形态和遗传变异。该项目包含了一系列职业生涯初期研究人员的培训机会，研究结果将通过公共数据库广泛传播。将通过三个具体目标估计夜光灯(茄科)的发散时间。首先，研究人员将修改该家族的所有化石记录，并使用传统和新开发的技术，包括可变压力扫描电子显微镜和X射线微计算机断层扫描，对一系列离散和连续的特征进行评分。其次，将为大约1600个现存物种创建一个匹配的形态数据集，其中包含先前系统发育分析中可用的分子数据。最后，贝叶斯全证据方法将被用来联合估计现存和灭绝物种之间的关系以及整个家族的分化时间。这个综合项目将由植物学家、古生物学家、成像专家和方法开发人员组成的团队进行。除了估计茄科的可靠时间表外，该项目还将扩大植物化石记录的知识，支持本科生和研究生以及博士后研究人员的培训，并加强国际科学基础设施和合作。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Reconstructing the timing of evolutionary events, from the invasion of land to the origin of flowers, relies on evidence from the fossil record. For many groups of organisms, available fossils are scant or poorly described, resulting in uncertainty about when major evolutionary transitions occurred. This project will expand knowledge about the fossil record and estimate an evolutionary timeline for a large and economically important plant group, the nightshades. This family of nearly 3000 species includes many crops, such as tomato, potato, and tobacco, and yet is represented in the fossil record by only a handful of described specimens. The researchers will survey putative nightshade fossils and use morphological and statistical analyses to determine their placement in the evolutionary history of the family. In the process, the researchers will be able to estimate the timing of major evolutionary changes, such as the origin of fleshy fruits and whole genome duplications. Understanding this evolutionary history is fundamental for crop improvement, which relies on the morphological and genetic variation accumulated through diversification over millions of years. This project incorporates a range of training opportunities for early-career researchers, and the results of the research will be widely disseminated through public data repositories.Divergence times across the nightshades (Solanaceae) will be estimated through three specific aims. First, the researchers will revise all fossil records from the family and score a suite of discrete and continuous characters using traditional and newly developed techniques, including variable pressure scanning electron microscopy and x-ray microcomputed tomography. Second, a matching morphological dataset will be created for the roughly 1600 extant species with available molecular data from previous phylogenetic analyses. Finally, Bayesian total-evidence methods will be used to jointly estimate relationships among extant and extinct species and divergence times across the family. This integrative project will be carried out by a team of botanists, paleontologists, imaging specialists, and methods developers. In addition to estimating a robust timeline for Solanaceae, the project will expand knowledge of the plant fossil record, support training of undergraduate and graduate students and a post-doctoral researcher, as well as strengthen international scientific infrastructure and collaboration.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.