Reliable estimates of when hominin taxa originated and went extinct are central to addressing many paleoanthropological questions, including those relating to macroevolutionary patterns. The timing of hominin temporal ranges can be used to test chronological predictions generated from phylogenetic hypotheses. For example, hypotheses of phyletic ancestor-descendant relationships, based on morphological data, predict no temporal range overlap between the two taxa. However, a fossil taxon's observed temporal range is almost certainly underestimated due to the incompleteness of both the fossil record itself and its sampling, and this decreases the likelihood of observing temporal overlap. Here, we focus on a well-known and widely accepted early hominin lineage, Australopithecus anamensis-afarensis, and place 95% confidence intervals (CIs) on its origination and extinction dates. We do so to assess whether its temporal range is consistent with it being a phyletic descendant of Ardipithecus ramidus and/or a direct ancestor to the earliest claimed representative of Homo (i.e., Ledi-Geraru). We find that the last appearance of Ar. ramidus falls within the origination CI of Au. anamensis-afarensis, whereas the claimed first appearance of Homo postdates the extinction CI. These results are consistent with Homo evolving from Au. anamensis-afarensis, but temporal overlap between Ar. ramidus and Au. anamensis-afarensis cannot be rejected at this time. Though additional samples are needed, future research should extend our initial analyses to incorporate the uncertainties surrounding the range endpoints of Ar. ramidus and earliest Homo. Overall, our findings demonstrate the need for quantifying the uncertainty surrounding the appearances and disappearances of hominin taxa in order to better understand the timing of evolutionary events in our clade's history.

中文翻译：

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人参来源和灭绝日期的统计估计：一个案例研究检查南方古猿Anafensis-afarensis血统。

关于人源生物群何时起源和灭绝的可靠估计，对于解决许多古人类学问题（包括与宏观进化模式有关的问题）至关重要。人参时间范围的时间可用于测试从系统发育假设中产生的时间顺序预测。例如，基于形态学数据的系统祖先关系的假设预测两个类群之间没有时间范围重叠。但是，由于化石记录本身及其采样的不完整性，几乎可以肯定地低估了化石分类单元的观测时间范围，这降低了观察时间重叠的可能性。在这里，我们着眼于一个广为人知的，广为人知的早期人类素谱系，Australopithecus anamensis-afarensis，并在其起源和灭绝日期上放置95％的置信区间（CI）。我们这样做是为了评估其时间范围是否与它是Ardipithecus ramidus的系统后代和/或最早声称的Homo代表（即Ledi-Geraru）的直接祖先相一致。我们发现Ar的最后一次出现。ramidus属于Au的起源CI。anamensis-afarensis，而声称的Homo首次出现则早于灭绝CI。这些结果与从金进化来的人是一致的。anamensis-afarensis，但Ar之间在时间上重叠。ramidus和金。anamensis-afarensis目前不能被拒绝。尽管还需要其他样本，但未来的研究应扩展我们的初始分析，以纳入围绕Ar范围终点的不确定性。ramidus和最早的人。全面的，