Molecular Phylogenetics of Colubroid Snakes (Colubroidea)

游蛇科 (Colubroidea) 的分子系统发育

• 批准号: 9107235
• 负责人: Edward Kraus
• 金额: $ 20.84万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-03-01 至 1996-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9107235&HistoricalAwards=false
• 关键词: Molecular; Phylogenetics; Colubroid; Snakes; Colubroidea

Determining genetic relationships among the various kinds of advanced snakes is a most difficult and challenging problem. The greatly simplified body plan of snakes offers few anatomical characters that can be used to distinguish among them, and in many cases two or more species have developed the same sets of anatomical characteristics independently. The past reliance on anatomical characteristics has, therefore, provided little in the way of reliable information about snake relationships. To rectify this, it is proposed that the DNA sequences of two mitochondrial genes be obtained from representatives of the eight largest presumptive groups of advanced snakes and, for comparative purposes, from two primitive snake groups. DNA sequence comparisons offer two huge advantages over anatomical comparisons for these studies. One is that the reduction in anatomical complexity is not reflected at the DNA level; the full range of DNA sequence complexity is present for use in determining relationships. The other is that, unlike the case with many anatomical changes, there is almost no possibility that the same sequence changes will occur independently in two different species; thus, with functional convergences from those due to genealogical inheritance. An accurate knowledge of the genetic relationships among advanced snakes is required for understanding the ways in which suites of characteristics develop. For example, knowing exactly how non-poisonous and poisonous snakes are related will resolve some of the controversies that presently surround the development of venom glands and the anatomical components for delivering venom. This knowledge will also provide the foundation for future studies of relationships among snake groups not examined here.

确定各种高级蛇之间的遗传关系是最困难和最具挑战性的问题。 蛇的身体结构大大简化，几乎没有可用于区分它们的解剖特征，并且在许多情况下，两个或多个物种独立地发展出相同的解剖特征。 因此，过去对解剖特征的依赖几乎没有提供有关蛇关系的可靠信息。 为了纠正这个问题，建议从八个最大的高级蛇类推定群体的代表中获得两个线粒体基因的DNA序列，并且出于比较的目的，从两个原始蛇类中获得两个线粒体基因的DNA序列。 对于这些研究来说，DNA 序列比较比解剖学比较有两大优势。 一是解剖复杂性的降低并没有体现在DNA层面；完整范围的 DNA 序列复杂性可用于确定关系。 另一个是，与许多解剖学变化的情况不同，相同的序列变化几乎不可能在两个不同的物种中独立发生； 因此，与因谱系继承而产生的功能趋同。 要了解一系列特征的发展方式，需要准确了解高级蛇之间的遗传关系。 例如，准确了解无毒蛇和有毒蛇之间的关系将解决目前围绕毒腺发育和释放毒液的解剖成分的一些争议。 这些知识也将为未来研究此处未研究的蛇类之间的关系奠定基础。