Parsimony Trees, Best-Fit Fences, and Consensus Sequences: Integrating Cladistics and Biostratigraphy at High Resolution

简约树、最佳拟合栅栏和共识序列：以高分辨率集成分支学和生物地层学

• 批准号: 9980372
• 负责人: Peter Sadler
• 金额: $ 12.5万
• 依托单位: University of California-Riverside
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2003-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9980372&HistoricalAwards=false
• 关键词: Parsimony; Trees; Best; Fit; Fences

9980372SadlerTree-shaped diagrams summarize evolutionary relationships between species or higher taxa. With species labels at the tips of branches, the rest of the tree depicts ancestry. Computer algorithms much for a branching pattern in the tree that most simply explains a large array of morphological and biochemical comparisons between the species. Similarities may be inherited from a common ancestor, or they may represent convergence of appearance between less closely related taxa - this complicates the search.Time correlations between strata at different localities are represented by fence-like diagrams. With the sequence of strata at each locality drawn on its own fence post, "wire lines' connect horizons of the same age from locality to locality. Many of the wire lines represent the time of origination of a fossil taxon. Because of imperfect preservation and collection of fossils, the localities tend to contradict one another in detail concerning the order of originations. Computer algorithms search for the fence that best resolves these contradictions.Searches for the best fences and trees typically find more than one equally good solution. The searches use different evidence; but trees and fences both include inferences about the order of appearance of morphological traits. This project will develop ways to combine the two search procedures so that each can help reduce the range of equally good solutions found by the other.

9980372Sadler树状图总结了物种或高等类群之间的进化关系。树枝顶端有物种标签，树的其余部分描绘了祖先。计算机算法在很大程度上解释了树上的分枝模式，最简单地解释了物种之间的大量形态和生化比较。相似性可能继承自一个共同的祖先，或者它们可能代表不太相关的分类群之间的外观趋同--这使搜索变得复杂。不同地点的地层之间的时间相关性用栅栏状的图表表示。随着每个地方的地层序列被画在自己的栅栏柱上，“铁丝网”将同一时代的地平线从一个地方连接到另一个地方。许多金属线代表了化石分类单元的起源时间。由于化石保存和收藏的不完善，各地在起源顺序上往往存在细节上的矛盾。计算机算法寻找最好地解决这些矛盾的栅栏。寻找最好的栅栏和树通常会找到不止一个同样好的解决方案。这些搜索使用了不同的证据；但树和栅栏都包括关于形态特征出现顺序的推断。该项目将开发将这两个搜索程序结合在一起的方法，以便每个程序都可以帮助缩小对方找到的同样好的解决方案的范围。