Ritchie Peter A, Millar Craig D, Gibb Gillian C, Baroni Carlo, Lambert David M
Allan Wilson Centre for Molecular Ecology and Evolution, Auckland.
Mol Biol Evol. 2004 Feb;21(2):240-8. doi: 10.1093/molbev/msh012. Epub 2003 Oct 31.
The timing of divergent events in history is one of the central goals of contemporary evolutionary biology. Such studies are however dependent on accurate evolutionary rates. Recent developments in ancient DNA analysis enable the estimation of more accurate evolutionary rates and therefore more accurate timing of divergence events. Consequently, this leads to a better understanding of changes in populations through time. We use an evolutionary rate calculated from ancient DNA of Adélie penguins (Pygoscelis adeliae) to time divergent events in their history. We report the presence of two distinct and highly variable mitochondrial DNA lineages and track changes in these lineages through space and time. When the ancient DNA and the phylogenetic rates are used to estimate the time of origin of the lineages, two very different estimates resulted. In addition, these same rates provide very different estimates of the time of expansion of these lineages. We suggest that the rate calculated from ancient DNA is more consistent with the glacial history of Antarctica and requires fewer assumptions than does a narrative based on the phylogenetic rate. Finally, we suggest that our study indicates an important new role for ancient DNA studies in the timing of divergent events in history.
历史上分歧事件的时间确定是当代进化生物学的核心目标之一。然而，此类研究依赖于准确的进化速率。古代DNA分析的最新进展使得更准确的进化速率估算成为可能，进而能更精确地确定分歧事件的时间。因此，这有助于更好地理解种群随时间的变化。我们利用从阿德利企鹅（Pygoscelis adeliae）古代DNA计算得出的进化速率来确定其历史中分歧事件的时间。我们报告了两个不同且高度可变的线粒体DNA谱系的存在，并追踪这些谱系在空间和时间上的变化。当使用古代DNA和系统发育速率来估计谱系的起源时间时，得到了两个截然不同的估计结果。此外，这些相同的速率对这些谱系扩张时间的估计也大相径庭。我们认为，从古代DNA计算得出的速率与南极洲的冰川历史更为一致，且与基于系统发育速率的描述相比，所需假设更少。最后，我们认为我们的研究表明古代DNA研究在确定历史上分歧事件的时间方面具有重要的新作用。
