Lineage and ecomorphological diversification of burrowing snakes

蛇是一个大的辐射（约。4,000种）的爬行动物，从蜥蜴的祖先进化而来。虽然蛇的早期进化史是激烈的争论，显着的过渡到一个细长的，无肢的身体形式通常被认为是进化为适应fossorial（穴居）的生活方式。土壤中的生命对形态施加了几个严重的功能限制，这导致了这样的观点，即无肢、头先入洞的穴居人不太可能经历快速或适应性辐射。令人惊讶的是，很少有研究探讨任何主要现存的穴居蛇谱系的生态形态多样化，尽管理解土壤中的进化（包括蛇的可能起源）的影响。SOILRAD将追踪Uropeltoidea的谱系多样性和生态形态学的适应可能性，Uropeltoidea是一个主要的土栖蛇谱系，在身体和头部形状上具有很大的多样性。在SOILRAD中，我将通过三个研究目标探索uropeltoid多样化：（1）。将三维几何形态测量应用于来自NHM的大量博物馆标本的microCT数据，以量化和识别骨骼形态（头骨、下颌骨和“颈”椎骨）的主要变化轴;（2）利用古DNA和下一代测序技术重建更完整的尾甲总科进化树;（3）评估谱系和生态形态多样化的速率和模式，并检验适应性辐射的假设。SOILRAD将提出最全面的系统发育假说和第一个关于尿骨盆骨骼学的广泛定量数据，并首次详细评估穴居蛇任何主要谱系的多样性。通过SOILRAD，我将接受CT成像，3D形态测量学，古代DNA方法，博物馆收藏管理，公众参与和其他专业技能的培训，这些技能将使我成为进化生物学研究的潜在研究小组领导者。

Snakes are a large radiation (ca. 4,000 species) of reptiles that evolved from lizard ancestors. Although the early evolutionary history of snakes is hotly debated, the remarkable transition to an elongated, limbless body form is generally thought to have evolved as an adaptation to a fossorial (burrowing) lifestyle. Life in soil imposes several, severe functional constraints on morphology and this has led to the view that limbless, headfirst burrowers are less likely to undergo rapid or adaptive radiation. Surprisingly, very few studies have explored the ecomorphological diversification of any major extant burrowing snake lineage, despite implications for understanding evolution in soils (including the possible origin of snakes). SOILRAD will trace the diversification of lineages and the adaptive possibilities of ecomorphology in Uropeltoidea, a major lineage of soil-dwelling snakes with great diversity in body and hea shape. In SOILRAD, I will explore uropeltoid diversification through three Research Objectives: (1.) apply 3-dimensional geometric morphometrics to microCT data from the huge collection of museum specimens at NHM, to quantify and identify the main axes of variation in skeletal morphology (skull, mandible and 'neck' vertebrae); (2.) use ancient DNA and Next-Generation sequencing techniques to reconstruct a more-complete evolutionary tree of Uropeltoidea; and (3.) assess rates and modes of lineage and ecomorphological diversification, and test hypotheses of adaptive radiation. SOILRAD will produce the most comprehensive phylogenetic hypothesis and first extensive quantitative data on uropeltoid osteology, and first detailed assessment of diversification in any major lineage of burrowing snakes. Through SOILRAD, I will be trained in CT imaging, 3D morphometrics, ancient DNA methods, museum collection management, public engagement and other professional skills that will establish me as a potential research-group leader in evolutionary biology research.