人类Y染色体最近的一个共同祖先
1Laboratory of Molecular Systematics and Evolution, Biosciences West, University of Arizona, Tucson 85721, USA.
Nature
|November 23, 1995
概括
对人类起源的研究表明,Y染色体的变异性减少. 这项研究没有发现最近强有力的选择的证据,估计188,000年前一个普通的人类Y染色体祖先.
科学领域:
- 人类进化遗传学人类进化遗传学
- 人口遗传学 人口遗传学
- 分子人类学分子人类学.
背景情况:
- 特定于男性的Y染色体对于追踪人类起源至关重要.
- 减少Y染色体上的核酸变异表明可能最近的强性选择.
- 这种减少的变异可能是由于单个Y染色体单元型的固定.
研究的目的:
- 为了研究人类Y染色体上核酸变异的模式.
- 为了测试最近对Y染色体进行选择性扫描的假设.
- 为了估计人类Y染色体的凝聚时间.
主要方法:
- 来自人类和黑猩猩Y染色体的2.6千基基片段的测序.
- 核酸序列多样性和分歧的分析.
- 将Y染色体数据与自体和线粒体DNA研究进行比较.
主要成果:
- 没有发现最近对人类Y染色体进行强有力的选择性扫描的证据.
- 人类Y染色体最近的共同祖先 (TMRCA) 的估计时间为188,000年 (95%CI:51,000411,000年).
- 结果与从其他遗传研究中估计的长期人类有效人口规模和性别比率一致.
结论:
- 观察到的Y染色体变异并不能通过最近的选择性扫描来解释.
- 估计的TMRCA支持最近人类起源的模型,而不是广泛的古老转变.
- 这些发现与人类进化多区域假设的预测相矛盾.
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Telomeres consist of non-coding repetitive nucleotide...
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