Navarro Arcadi, Barton Nick H
Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Doctor Aiguader 80, 08003 Barcelona, Catalonia, Spain.
Science. 2003 Apr 11;300(5617):321-4. doi: 10.1126/science.1080600.
Humans and their closest evolutionary relatives, the chimpanzees, differ in approximately 1.24% of their genomic DNA sequences. The fraction of these changes accumulated during the speciation processes that have separated the two lineages may be of special relevance in understanding the basis of their differences. We analyzed human and chimpanzee sequence data to search for the patterns of divergence and polymorphism predicted by a theoretical model of speciation. According to the model, positively selected changes should accumulate in chromosomes that present fixed structural differences, such as inversions, between the two species. Protein evolution was more than 2.2 times faster in chromosomes that had undergone structural rearrangements compared with colinear chromosomes. Also, nucleotide variability is slightly lower in rearranged chromosomes. These patterns of divergence and polymorphism may be, at least in part, the molecular footprint of speciation events in the human and chimpanzee lineages.
人类与其在进化上关系最近的亲属黑猩猩相比，基因组DNA序列约有1.24%的差异。在将这两个谱系分隔开来的物种形成过程中积累的这些变化的比例，对于理解它们差异的基础可能具有特殊意义。我们分析了人类和黑猩猩的序列数据，以寻找物种形成理论模型所预测的分歧和多态性模式。根据该模型，正选择的变化应该积累在两个物种之间存在固定结构差异（如倒位）的染色体上。与共线染色体相比，经历了结构重排的染色体上的蛋白质进化速度快了2.2倍以上。此外，重排染色体中的核苷酸变异性略低。这些分歧和多态性模式可能至少部分是人类和黑猩猩谱系中物种形成事件的分子印记。
