| 摘要: |
| 【目的】研究在较复杂的核苷酸替换模型，即Tamura模型下DNA序列中4种核苷酸频率随世代变化的规律，以得到序列熵的性质，为了解生物进化机理奠定基础。【方法】在Shannon信息熵理论基础上，利用Lagrange乘数法进行理论证明，并用Mathematica软件模拟了Tamura模型下DNA序列中4种核苷酸组成的变化规律和序列熵的变化过程。【结果】DNA序列在Tamura模型下发生突变，各核苷酸频率随世代变化逐渐趋于平衡，且序列熵趋于最大值。【结论】核苷酸突变具有保熵性，验证了前人生物是朝着多样性增大的方向发展进化的结论。 |
| 关键词: 生物多样性 Shannon信息熵 核苷酸替换 Tamura模型 |
| DOI： |
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| 基金项目:西北农林科技大学引进人才科研启动费项目（Z11021105） |
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| Entropy properties of the point mutations in DNA sequence using Tamura model |
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GUO Zihu, ZHANG Ruiming, YUAN Zhifa
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Northwest A&F University
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| Abstract: |
| 【Objective】The changing of the frequencies of 4 nucleotides as the generations changed using Tamura model,which is a more complicated nucleotide substitution model,was studied to obtain the entropy properties of DNA sequences.【Method】Based on Shannon entropy theory,the theoretical demonstration was proved by the Lagrange Multiplier Method,and Mathematica was used to simulate the changing patterns of 4 nucleotides.【Result】If the mutation in the DNA sequence occurs in Tamura model,the frequencies of nucleotides tend to equilibrium,and their entropies tend to the maximum.【Conclusion】The nucleotide mutations can maintain their entropy.It was verified that biodiversity of species increased during evolvement. |
| Key words: biodiversity Shannon entropy nucleotide substitution Tamura model |
