ABR: Evolution of 13- and 17- year Periodical Cicadas

小行星9807113 早期的研究探索了周期性蝉（属magicicada）的进化使用线粒体基因序列，核编码蛋白质和腹部颜色。 该项目的结果包括线粒体和核基因组的空间模式的遗传特征，三个强大的遗传边界的识别，不完全对应于周期性的物种之间的边界，并实现生活史变异的重要性，在这个不寻常的属的进化。 在这项工作的过程中，研究了线粒体基因组保守区和可变区的进化，并发表了许多论文，研究了分子二级结构对核苷酸比对和理解核苷酸进化速率中位点间变异模式的价值。 速率变化的影响，进化树的建设，评估支持的物种分组，并计算遗传距离进行了探讨。 在1998年，将有一个联合出现的只有两个窝的13和17岁的蝉，其范围目前重叠。 这将为研究我们以前发现的遗传边界提供一个独特的机会。 五种用于识别13岁和17岁蝉的遗传技术已经完善。 将更详细地审查所有六种周期性生物物种的生命周期转换。 先前描述的遗传界限将被探索，试图了解其原因。 最后，将增加一个新的组成部分，研究生态相互作用对生命周期时间和物种共同进化的影响。 通过研究这些不寻常的蝉，我们可以更多地了解生活史进化如何戏剧性地影响物种进化，并在这样做的时候回答了以前由NSF资助的研究产生的关于周期性蝉的一系列广泛的问题。 该项目的生态组成部分将为研究这一不寻常的昆虫群体的共同多样化提供一个新的维度。

9807113 Simon Earlier research explored the evolution of periodical cicadas (Genus Magicicada) using mitochondrial gene sequences, nuclear encoded proteins, and abdominal color. Results from the project included a genetic characterization of spatial patterning of mitochondrial and nuclear genomes, identification of three strong genetic boundaries that do not correspond precisely to the boundaries between periodical cicada species, and a realization of the importance of life history variation in the evolution of this unusual genus. In the process of this work, the evolution of conserved and variable regions of the mitochondrial genome was studied and a number of papers were produced which investigated the value of the secondary structure of the molecule for alignment of nucleo- tides and for understanding patterns of site-to-site variation in the rate of nucleotide evolution. The effects of rate variation on evolutionary tree construction, evaluation of support for groupings of species, and calculation of genetic distances were also explored. In 1998 there will be a joint emergence of the only two broods of 13- and 17-year cicadas whose ranges currently overlap. This will provide a unique opportunity to study the genetic boundaries that we previously discovered. Five genetic techniques for identifying 13- versus 17-year cicadas have been perfected. Life-cycle switching will be examined in greater detail for all six of the periodical cicada species. Previously described genetic boundaries will be explored in an attempt to understand their causes. Finally, a new component will be added to the research, an exploration of the effects of ecological interactions on life-cycle timing and species co-evolution. By studying these unusual cicadas we can learn more about how life-history evolution can dramatically effect species evolution and in so doing answer a broad array of questions about periodi- cal cicadas generated by previous NSF-funded research. The ecological component o f this project will lend an added dimension to the study of co-diversification of this unusual group of insects.