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A simple agent‐based model is presented that produces results matching the experimental data found by Lenski's group for ≤50,000 generations of Escherichia coli bacteria under continuous selective pressure. Although various mathematical models have been devised previously to model the Lenski data, the present model has advantages in terms of overall simplicity and conceptual accessibility. The model also clearly illustrates a number of features of the evolutionary process that are otherwise not obvious, such as the roles of epistasis and historical contingency in adaptation and why evolution is time irreversible ('Dollo's law'). The reason for this irreversibility is that genomes become increasingly integrated or organized, and this organization becomes a novel selective factor itself, against which future generations must compete. Selection for integrated or synergistic networks, systems or sets of mutations or traits, not for individual mutations, confers the main adaptive advantage. The result is a punctuated form of evolution that follows a logarithmic occurrence probability, in which evolution proceeds very quickly when interactomes begin to form but which slows as interactomes become more robust and the difficulty of integrating new mutations increases. Sufficient parameters exist in the game to suggest not only how equilibrium or stasis is reached but also the conditions in which it will be punctuated, the factors governing the rate at which genomic organization occurs and novel traits appear, and how population size, genome size and gene variability affect these. [ABSTRACT FROM AUTHOR]

Genetic architecture of yield and yield contributing characters of five crosses in chickpea were performed by generation mean analysis. Non-significant χ2 values were noted for plant weight at harvest (PWH), number of pods per plant (NPd/P) and number of seeds per plant (NS/P) in cross-2; for number of secondary branches at first flower (NSBFF) and number of secondary branches at maximum flower (NSBMF) in cross-3 and for number of primary branches at maximum flower (NPBMF) in cross-4. Among these, PWH in cross-2; NSBFF and NSBMF in cross-3 and NPBMF in cross-4 were also non-significant regarding C and D scales. Non-significant scale coupled with non-significant χ2 values indicated only additive-dominance relationship for those characters and crosses that would likely be helpful in doing successful breeding plan easily for the development of potential lines in chickpea. Gene effects viz., additive [d], dominance [h], additive × additive [i] and dominance × dominance [l] were significant for different crosses and characters indicating involvement of additive, dominance, additive × additive and dominance × dominance gene interactions in the control of these traits. Most of the studied characters exhibited duplicate type of epistasis therefore, recurrent selection for these traits is suggested. Effective factor (K1) was less than one for all the characters and crosses indicating minimum one group of gene controlled the characters. Both broad (h2b) and narrow (h2n) sense heritability in majority cases were found to be high which indicates that selection for high heritability showing traits is likely to be effective. Mid-parent (MP) and better-parent (BP) heterosis found to be non-significant in maximum cases. All the characters and crosses showed non-significant inbreeding depression (ID) indicating a good sign for further genetic work. [ABSTRACT FROM AUTHOR]