Collaborative Research: Araneid Phylogeny and Evolution of Spider Silk Phenotypes.

蜘蛛产生的不同种类的丝具有显著的物理特性。一些蜘蛛丝在断裂前甚至能吸收比高性能人造材料更多的能量。球网是一个突出的例子，它结合了两种类型的丝纤维的特性，即坚硬的支撑线和有弹性的捕获螺旋，以吸收飞行昆虫猎物的高能量冲击。然而，由不同种类的蜘蛛织成的圆球网可以有完全不同的形状。该项目旨在了解蜘蛛丝的机械功能如何随着不同种类蜘蛛织网方式的变化而进化。这项研究将包括三个步骤。1)它将通过使用新的DNA数据和扩展的形态学数据，为圆织蜘蛛之间的进化关系提出第一个强有力的假设。2)对网的形状进行测量，并对网的两种组成纤维——框架丝和粘捕丝的材料性能进行量化。这将包括测试由生态多样化的织球蜘蛛样本所纺出的丝纤维的强度、弹性和韧性。3)这两种类型的数据将被结合起来，以研究不同的圆织蜘蛛的蛛丝的生物力学特性是如何与网的形状共同进化的，这些蜘蛛既有相似的生态环境，也有非常不同的生态环境。这个项目将产生三个主要的更广泛的影响；1)促进蜘蛛丝的生物技术开发，2)对科学领域代表性不足的学生进行指导，3)促进公众科学素养。蜘蛛丝的优异性能使其成为开发仿生超纤维和织物的理想模型。这个项目将展示生物勘探者如何利用网的形状作为蜘蛛纺丝的指标。它还将决定蚕丝的不同机械性能彼此独立变化的程度。这些知识对于生物工程重组蜘蛛丝的努力是必不可少的，以满足需要独特的强度和拉伸组合的定制应用。本科生每年通过自主项目的开发和完成，积极参与本项目的基础科学研究。这些项目将涉及网络进化和丝绸力学，其中一些学生甚至将参加到非洲和南美的实地研究旅行，在那里他们将接触到与生物多样性相关的研究和新的文化。这一点尤其重要，因为阿克伦大学的学生主要来自人口稠密的俄亥俄州东北部，大多数生物学学生都是女性，其中30%以上的学生来自代表性不足的少数民族。这些学生中的许多人没有接触过基础科学研究，也没有接触过科学领域的职业发展机会。最后，调查人员将利用媒体对蜘蛛网和丝绸的兴趣来提高公众对生物多样性和经常被误解的进化过程的认识。他们还将利用这项研究，通过在阿克伦大学建立的暑期实习项目，向高中生介绍基础科学研究与工业之间的关系。

Public abstract Spiders produce different types of silks that have remarkable physical properties. Some spider silk can even absorb more energy before breaking than high performance manmade materials. Orb webs are an outstanding example of how a combination of properties from two types of silk fibers, stiff supporting threads and stretchy capture spirals, function to absorb the high energy impacts of flying insect prey. Yet, orb webs spun by different species of spiders can have radically different shapes. This project seeks to understand how the mechanical function of spider silk may evolve in relation to changes in the way different species of spiders spin webs. The research will involve three steps. 1) It will produce the first robust hypothesis for evolutionary relationships among orb-weaving spiders by using novel DNA data and expanded data on morphology. 2) It will measure the shapes of webs and quantify the material properties for the two constituent fibers of orb webs, frame threads and sticky capture silk. This will include testing the strength, stretchiness, and toughness of the silk fibers spun by an ecologically diverse sampling of orb-weaving spiders. 3) These two types of data will then be combined to examine the how the biomechanical properties of silks coevolve with web shape among different of orb-weaving spiders that have both similar and very different ecologies from one another. This project will have three primary broader impacts; 1) facilitating biotechnological exploitation of spider silks, 2) mentoring of underrepresented students in science, and 3) contributing to public scientific literacy. The extreme performance of spider silk makes it a desirable model for the development of biomimetic superfibers and fabrics. This project will demonstrate how web shape can be used by bioprospectors as an indicator for spiders that spin mechanically unusual silks. It will also determine the degree to which different mechanical properties of silks can change independently of one another. This knowledge is essential for efforts to bioengineer recombinant spider silk for customized applications that require unique combinations of strength and stretchiness. Undergraduates will be actively involved in basic scientific research each year of this project through the development and completion of independent projects. These projects will relate to web evolution and silk mechanics and some of these students will even participate in field research excursions to Africa and South America, where they will gain exposure to biodiversity related research and to new cultures. This is particularly relevant, because U Akron students are predominately from heavily populated northeastern Ohio and a majority of biology students are female, with more than 30% from under-represented minority ethnic groups. Many of these students have not been exposed to basic scientific research or to career possibilities in the sciences. Finally, the investigators will use the media's interest in spider webs and silk to enhance the public's knowledge of biodiversity and the often-misunderstood process of evolution. They will also use the research to introduce high school students to the relationship between basic scientific research and industry through established summer internship programs at U Akron.