Department of Anthropology, Northern Illinois University, DeKalb, Illinois, USA.
School of Biological and Environmental Sciences, Universidad San Francisco de Quito, Quito, Ecuador.
Am J Phys Anthropol. 2021 May;175(1):251-267. doi: 10.1002/ajpa.24266. Epub 2021 Mar 9.
We investigated the diversity of the pygmy marmoset, Cebuella pygmaea, by comparing genetic, morphological and pelage traits of animals from Peru and Ecuador.
We extracted DNA from museum specimen osteocrusts and from fecal samples collected from free-ranging individuals. We sequenced the mtDNA cytochrome b gene and the control region from samples collected at 13 different sites and used Bayesian inference and Maximum Likelihood to identify distinct clades. We took measurements of the crania of a subset of these specimens (n = 26) and ran a logistic regression to determine if any of the cranial measurements (n = 22) could predict a specimen's clade. In addition, we examined the pelage patterns of the museum specimens and photographs taken of free-ranging individuals and divided them into pelage types based on coloration of the underbelly.
We identified two divergent clades, and two distinct groups with clear geographic boundaries within one of those clades. Two measurements of the zygomatic bone perfectly predicted a given individual's mtDNA clade. We found four distinct pelage patterns in our samples, but these patterns are variable within clades and among individuals within the same population.
These analyses indicate that the two recognized subspecies of pygmy marmoset should be elevated to the species level (C. pygmaea and C. niveiventris) based on molecular and cranial differences but not on pelage patterns. We provide evidence on the geographic limits of the two clades and identify regions where additional sampling is required to better define the geographic distribution of the two clades.
通过比较来自秘鲁和厄瓜多尔的动物的遗传、形态和被毛特征，研究侏狨的多样性。
我们从博物馆标本的骨皮质和自由生活个体的粪便样本中提取 DNA。我们对来自 13 个不同地点的样本进行了 mtDNA 细胞色素 b 基因和控制区的测序，并使用贝叶斯推断和最大似然法来识别不同的分支。我们对这些标本中的一部分进行了颅骨测量（n=26），并进行了逻辑回归分析，以确定任何颅骨测量（n=22）是否可以预测标本的分支。此外，我们检查了博物馆标本的被毛模式和自由生活个体的照片，并根据腹部颜色将它们分为被毛类型。
我们确定了两个分歧的分支，以及在其中一个分支内有明显地理边界的两个不同群体。颧骨的两个测量值可以完美地预测给定个体的 mtDNA 分支。我们在样本中发现了四种不同的被毛模式，但这些模式在分支内和同一群体内的个体之间是可变的。
这些分析表明，两种公认的侏狨亚种应根据分子和颅骨差异提升到种的水平（C. pygmaea 和 C. niveiventris），但不根据被毛模式。我们提供了关于两个分支的地理界限的证据，并确定了需要额外采样的区域，以更好地定义两个分支的地理分布。
