Schrago Carlos G
Universidade Federal do Rio de Janeiro, Instituto de Biologia, Departamento de Genética, CCS, A2-092, Rua Prof. Rodolpho Paulo Rocco, SN Cidade Universitária, Rio de Janeiro CEP 21941-617, Brazil.
J Theor Biol. 2014 Sep 21;357:55-61. doi: 10.1016/j.jtbi.2014.05.009. Epub 2014 May 14.
The effective population size is a fundamental parameter for the understanding of microevolutionary process. Indeed, the consideration of population-level phenomena within phylogenies provides insight into the influence of the past evolutionary demography on the genetic diversity of living species. Although the effective population size of the last common ancestor of humans and chimpanzees has been extensively investigated by molecular evolutionists, variance in the estimates of this parameter among studies is large. However, with the availability of genome sequences, the estimation of evolutionary parameters may be conducted with minimum stochastic error, and the limiting distribution of the estimates may be obtained. This statistical property was utilized in the present study and coupled with analytical derivations from the coalescent theory to examine the limiting distribution of the ancestral effective population size of Homo-Pan. The mean ancestral effective population size of Homo-Pan was inferred at approximately 47,500, and the results showed that the uncertainty of the estimates was large, even under the limiting distribution. Further reductions of the estimates are feasible only if additional calibration information from the fossil record is provided and if a probabilistic model of ancestral generation time is envisioned.
有效种群大小是理解微观进化过程的一个基本参数。的确，在系统发育中考虑种群水平的现象能洞察过去进化人口统计学对现存物种遗传多样性的影响。尽管人类和黑猩猩的最后共同祖先的有效种群大小已被分子进化生物学家广泛研究，但不同研究中该参数估计值的差异很大。然而，随着基因组序列的可得性，进化参数的估计可以在最小随机误差下进行，并且可以获得估计值的极限分布。本研究利用了这一统计特性，并结合了溯祖理论的解析推导，以检验人猿祖先有效种群大小的极限分布。人猿祖先有效种群大小的均值推断约为47500，结果表明即使在极限分布下，估计值的不确定性仍然很大。只有提供来自化石记录的额外校准信息，并设想一个祖先世代时间的概率模型，估计值才有可能进一步降低。
