http://hdl.handle.net/2117/7212 2013-06-20T05:57:14Z http://hdl.handle.net/2117/14563 Title: Random models of Menzerath-Altmann law in genomes Authors: Baixeries i Juvillà, Jaume; Hernández Fernández, Antonio; Ferrer Cancho, Ramon Abstract: Recently, a random breakage model has been proposed to explain the negative correlation between mean chromosome length and chromosome number that is found in many groups of species and is consistent with Menzerath–Altmann law, a statistical law that defines the dependency between the mean size of the whole and the number of parts in quantitative linguistics. Here, the central assumption of the model, namely that genome size is independent from chromosome number is reviewed. This assumption is shown to be unrealistic from the perspective of chromosome structure and the statistical analysis of real genomes. A general class of random models, including that random breakage model, is analyzed. For any model within this class, a power law with an exponent of −1 is predicted for the expectation of the mean chromosome size as a function of chromosome length, a functional dependency that is not supported by real genomes. The random breakage and variants keeping genome size and chromosome number independent raise no serious objection to the relevance of correlations consistent with Menzerath–Altmann law across taxonomic groups and the possibility of a connection between human language and genomes through that law. 2012-01-16T11:48:19Z http://hdl.handle.net/2117/13368 Title: Size of the whole versus number of parts in genomes Authors: Hernández Fernández, Antonio; Baixeries i Juvillà, Jaume; Forns, Núria; Ferrer Cancho, Ramon Abstract: It is known that chromosome number tends to decrease as genome size increases in angiosperm plants. Here the relationship between number of parts (the chromosomes) and size of the whole (the genome) is studied for other groups of organisms from different kingdoms. Two major results are obtained. First, the finding of relationships of the kind "the more parts the smaller the whole" as in angiosperms, but also relationships of the kind "the more parts the larger the whole". Second, these dependencies are not linear in general. The implications of the dependencies between genome size and chromosome number are two-fold. First, they indicate that arguments against the relevance of the finding of negative correlations consistent with Menzerath-Altmann law (a linguistic law that relates the size of the parts with the size of the whole) in genomes are seriously flawed. Second, they unravel the weakness of a recent model of chromosome lengths based upon random breakage that assumes that chromosome number and genome size are independent. 2011-09-28T08:53:18Z