NSF Postdoctoral Fellowship in Biology FY 2020: Integrating the fossil record with developmental biology to investigate the origin of the avian body plan

这项行动资助了2020财年NSF生物学博士后研究奖学金，使用生物收集的研究。该研究金支持研究员的研究和培训，以创新的方式使用生物收藏品。化石直接记录了动物进化中的重大变化，否则这些变化将被时间所遗忘。这些变化可以追溯到动物仍然是发育中的胚胎时发生的过程。因此，整合胚胎和化石的数据对于理解进化如何产生新的动物形式至关重要。该项目将把鸟类向鸟类过渡的优秀化石记录与新的发育技术相结合，以高分辨率的三维方式对现代鸟类胚胎进行成像，重点是鸟类的骨盆（臀部）。这位研究员的初步数据有力地表明，早期鸟类胚胎的骨盆与鸟类祖先的骨盆具有相同的解剖结构。在鸟类发育的两天内，可以看到从一个类似羽毛的骨盆到一个鸟类骨盆的转变，这显示了形成现代鸟类解剖结构的惊人的进化发育机制。该项目将整合化石和胚胎的3D模型，以证实这一初步发现，阐明生命史上的一个主要进化转变。该项目还将允许来自代表性不足的群体的学生进行培训，利用研究动物的魅力来寻找广泛的吸引力。这位研究员假设，鸟类骨盆发育的早期阶段类似于祖先的马丘比丘状态（一个被称为终端添加的过程），并且鸟类骨盆在胚胎发育期间所经历的变化可能反映了进化历史。初步数据强烈表明，早期鸟类胚胎的骨盆保留了祖先的阿留申状态，并在后期发育阶段过渡到经典的“鸟类”解剖结构。该研究员将整合来自博物馆收藏的化石/骨骼生物医学成像（微型计算机断层扫描[micro-CT]）的数据，以及来自用于描述三维胚胎组织的新胚胎学技术的数据，这些胚胎学技术的阶段早于以前。这将允许化石中记录的进化序列和鸟类胚胎中已知的发育序列进行定性和定量比较（使用3D几何形态测量学）。然后，研究员将利用“软”（非骨骼）组织的发育来重建从非鸟类兽脚亚目恐龙到鸟类过渡期间肌肉和神经的进化。这将通过使用基于自然历史收藏的新胚胎学方法来阐明脊椎动物历史上最具标志性的转变之一。为了扩大工作的影响，该研究员将培训来自研究中代表性不足的群体的学生。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2020, Research Using Biological Collections. The fellowship supports research and training of the fellow that will use biological collections in innovative ways. Fossils directly record major changes in animal evolution that would otherwise be lost to time. These changes can be traced back to processes occurring while the animal is still a developing embryo. Therefore, integrating data from both embryos and fossils is critical to understanding how evolution generates new animal forms. This project will integrate the excellent fossil record of the dinosaur-to-bird transition with new developmental techniques to image modern-day bird embryos in high resolution in three dimensions, focusing on the bird pelvis (hips). The fellow’s preliminary data strongly suggest that the pelvis of early-stage bird embryos has the same anatomy as the dinosaurian ancestors of birds. The transition from a dinosaur-like pelvis to a bird pelvis can be seen across 2 days of bird development, showing the striking evolutionary developmental mechanism that formed the anatomy of modern birds. This project will integrate 3D models of both fossils and embryos to confirm this initial finding, illuminating one of the major evolutionary transitions in the history of life. This project will also allow for the training of students from underrepresented groups, leveraging the charisma of the study animals to find broad appeal. The fellow hypothesizes that the early stages of avian pelvic development resemble ancestral dinosaurian states (a process called terminal addition), and that the changes undergone by the avian pelvis during embryonic development may mirror evolutionary history. Preliminary data strongly suggest that the pelvis of early-stage bird embryos retains ancestral dinosaurian states and transitions to the classic ‘avian’ anatomy in later developmental stages. The fellow will integrate data from biomedical imaging (micro-computed tomography [micro-CT]) of fossils/skeletons housed in museum collections with data from novel embryological techniques used to describe three-dimensional embryonic tissues at stages earlier than has been previously possible. This will allow the evolutionary sequence recorded in the fossils and the developmental sequence known from avian embryos to be compared qualitatively and quantitatively (with 3D geometric morphometrics). The fellow will then use the development of ‘soft’ (non-skeletal) tissues to reconstruct the evolution of muscles and nerves during the transition from non-avian theropod dinosaurs to birds. This will illuminate one of the most iconic transformations in vertebrate history by using new embryological methodologies grounded in natural history collections. To broaden the impact of the work, the fellow will train students from underrepresented groups in research.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.