Many methods exist for detecting introgression between nonsister species, but the most commonly used require either a single sequence from four or more taxa or multiple sequences from each of three taxa. Here, we present a test for introgression that uses only a single sequence from three taxa. This test, denoted D3, uses similar logic as the standard D-test for introgression, but by using pairwise distances instead of site patterns it is able to detect the same signal of introgression with fewer species. We use simulations to show that D3 has statistical power almost equal to D, demonstrating its use on a data set of wild bananas (Musa). The new test is easy to apply and easy to interpret, and should find wide use among currently available data sets.

中文翻译：

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渗入的三样本测试。

存在许多用于检测非姐妹物种之间渗入的方法，但是最常用的方法需要来自四个或更多分类单元的单个序列或来自三个分类单元的每个的多个序列。在这里，我们提出了一种渐渗测试，该测试仅使用来自三个分类单元的单个序列。此测试用D3表示，与标准的渗入测试使用相似的逻辑，但是通过使用成对距离而不是位点模式，它可以检测到较少种类的相同渗入信号。我们使用模拟显示D3的统计功效几乎等于D，这证明了其在野生香蕉（Musa）数据集上的使用。新的测试易于应用且易于解释，并且应该在当前可用的数据集中得到广泛的使用。