UMR 2724177, INTERTRYP, CIRAD-IRD, Baillarguet, France.
Infect Genet Evol. 2019 Jun;70:197-207. doi: 10.1016/j.meegid.2019.03.002. Epub 2019 Mar 7.
In medical entomology, as well as in many other groups of arthropods, geometric morphometrics has become a powerful tool for species identification and population characterization. The approach lies on the relative position of some anatomical points (landmarks) or, more recently, of curved features (semilandmarks). Landmarks are described by coordinates of points easy to recognize from one individual to another. According to this criterion decreasing levels of homology have been recognized, going from strong (type I) to weak (type III landmarks). Semilandmarks (or sliding landmarks) are points having poor homology like landmarks III, but making it possible to capture curves or surfaces where landmarks are sparse. Their use is becoming increasingly routine. Superimposition of semilandmarks differ from what is currently applied to landmarks, ways and tools for collecting them may also differ from collecting landmarks. They can be collected by simply digitizing points along a curve or a surface but can also be collected in a more systematic way by the use of a template. In the CLIC package (https://xyom-clic.eu), as well as in the XYOM software (https://xyom.io), we created an algorithm-based template to both collect and align semilandmarks or landmarks III. The use of such template for the final alignment of these special points represents an original approach, so that a comprehensive explanation is required. Using a published example, we compare in details the results of our method with the ones produced by the currently applied approaches. A close parallelism of information is found. The specificities and limitations of our method are discussed.
在医学昆虫学以及许多其他节肢动物群体中，几何形态测量学已成为鉴定物种和描述种群特征的有力工具。该方法基于一些解剖学特征的相对位置（标志点），或者最近，基于弯曲特征（半标志点）。标志点通过易于从一个个体识别到另一个个体的点的坐标来描述。根据这个标准，已经认识到同源性程度逐渐降低，从强（I 型）到弱（III 型标志点）。半标志点（或滑动标志点）与标志点 III 具有相似的低同源性，但可以捕捉标志点稀疏的曲线或曲面。它们的使用变得越来越常规。半标志点的叠加与当前应用于标志点的方法不同，收集它们的方式和工具也可能与收集标志点不同。它们可以通过简单地沿着曲线或曲面数字化点来收集，也可以通过使用模板以更系统的方式收集。在 CLIC 包（https://xyom-clic.eu）和 XYOM 软件（https://xyom.io）中，我们创建了一个基于算法的模板，用于收集和对齐半标志点或标志点 III。使用这种模板对这些特殊点进行最终对齐是一种创新方法，因此需要进行全面解释。我们使用已发表的示例详细比较了我们的方法与当前应用方法的结果。发现信息具有紧密的平行性。讨论了我们方法的特点和局限性。
