逻辑斯缔方程在研究原始生物大分子动态及生命起源问题中的应用

APPLICATION OF LOGISTIC EQUATIONS TO THE STUDY ON THE DYNAMICS OF PRIMITIVE BIOLOGICAL MACROMOLECULES AND THE ORIGIN OF LIFE

通过论证及重新定义逻辑斯缔方程，本文提出和进一步发展了原始生物大分子动态的数学模型．对该模型的４种竞争增长结果进行分析，得出最有可能的原始生物大分子的发展动态，并由此推导出原始生物圈中较大量存在的只是种类单一的原始生物大分子的结论。对这一结论在生命起源和生物进化中的意义进行了探讨，指出生命起源初期的生物多样性是很低的，原始生物世界是一个重复序列或重复结构的世界，生物进化是通过不断增加和扩展生态位，使生物多样性不断提高。最后，讨论了生态学的概念和方法在微观水平上应用的理论基础，指出从生态学的角度去进行分子生物学的研究是一种发展趋势。

mathematical model for the dynamics of primitive biological macromolecules was pro-posed and further developed by redefining the logistic equations as follows:N_m, the copynumber of a kind of biological macromolecule in primitive environment at time t;r_m,the in-trinsic replicating capacity(rate) of the macromolecule;K_m,The carrying capacity(resourcelimit)of the primitive environment;the instantaneous rate of increase in copy number of the primitive biological macromolecule;β_(12)andβ_(21),competition coefficients.From an analysisof the four outcomes of competitive growth deduced from the model,the most possible sce-nario for the dynamics of primitive biological macromolecules was developed. On this basis,aconclusion could be drawn that the abundant biological macromolecules in the primitive bio-sphere would be almost the same kind.This conclusion is of importance for the origin of lifeand in biological evolution. It could imply that the biological diversity would be very lowshortly after the origin of life on the earth,and the primitive biological world would be aworld of repeated sequence or repetitive structure. Biological evolution would.go from a lowto high biological diversity by raising and extending ecological niches. Finally, in a broadertheoretical background,the basis for the application of the concepts and methods in ecologyat microscopic level was discussed. It is outlined that the study of molecular biology from anecological point of view is a tendency in this field.