Department of Anthropology, Boston University, Boston, MA 02215, USA.
Proc Natl Acad Sci U S A. 2012 Sep 25;109(39):15716-21. doi: 10.1073/pnas.1211740109. Epub 2012 Aug 13.
Fossils and molecular data are two independent sources of information that should in principle provide consistent inferences of when evolutionary lineages diverged. Here we use an alternative approach to genetic inference of species split times in recent human and ape evolution that is independent of the fossil record. We first use genetic parentage information on a large number of wild chimpanzees and mountain gorillas to directly infer their average generation times. We then compare these generation time estimates with those of humans and apply recent estimates of the human mutation rate per generation to derive estimates of split times of great apes and humans that are independent of fossil calibration. We date the human-chimpanzee split to at least 7-8 million years and the population split between Neanderthals and modern humans to 400,000-800,000 y ago. This suggests that molecular divergence dates may not be in conflict with the attribution of 6- to 7-million-y-old fossils to the human lineage and 400,000-y-old fossils to the Neanderthal lineage.
化石和分子数据是两种独立的信息来源，原则上应该提供关于进化谱系何时分化的一致推断。在这里，我们使用一种与化石记录无关的、用于推断近代人类和类人猿进化中物种分化时间的遗传推断的替代方法。我们首先利用大量野生黑猩猩和山地大猩猩的遗传亲子关系信息，直接推断它们的平均世代时间。然后，我们将这些世代时间估计值与人类的进行比较，并应用最近对人类每代突变率的估计值，得出与化石校准无关的大型类人猿和人类分化时间的估计值。我们将人类与黑猩猩的分化时间追溯到至少 700 万至 800 万年前，将尼安德特人和现代人类之间的种群分化时间追溯到 40 万至 80 万年前。这表明，分子分歧日期可能与将 600 万至 700 万年前的化石归因于人类谱系，以及将 40 万年前的化石归因于尼安德特人谱系的说法并不矛盾。
