Search results
Results From The WOW.Com Content Network
The first generation is created by applying the above rules simultaneously to every cell in the seed, live or dead; births and deaths occur simultaneously, and the discrete moment at which this happens is sometimes called a tick. [nb 1] Each generation is a pure function of the preceding one. The rules continue to be applied repeatedly to ...
In developmental biology, pattern formation refers to the generation of complex organizations of cell fates in space and time. The role of genes in pattern formation is an aspect of morphogenesis, the creation of diverse anatomies from similar genes, now being explored in the science of evolutionary developmental biology or evo-devo.
[7] Fixation rates can easily be modeled as well to see how long it takes for a gene to become fixed with varying population sizes and generations. For example, The Biology Project Genetic Drift Simulation allows to model genetic drift and see how quickly the gene for worm color goes to fixation in terms of generations for different population ...
One may then define the generation time as the time it takes for the population to increase by a factor of . For example, in microbiology , a population of cells undergoing exponential growth by mitosis replaces each cell by two daughter cells, so that R 0 = 2 {\displaystyle \textstyle R_{0}=2} and T {\displaystyle T} is the population doubling ...
The frequency of new mutations at a particular locus or in a particular gene, sequence, genome, or organism over a specified period of time, e.g. during a single generation. Mutation rates may be calculated for a specific class of mutation or for all types collectively; they vary widely by organism and with an organism's environment.
The most common formulation of a branching process is that of the Galton–Watson process.Let Z n denote the state in period n (often interpreted as the size of generation n), and let X n,i be a random variable denoting the number of direct successors of member i in period n, where X n,i are independent and identically distributed random variables over all n ∈{ 0, 1, 2, ...} and i ∈ {1 ...
Genetic variability is either the presence of, or the generation of, genetic differences. It is defined as "the formation of individuals differing in genotype, or the presence of genotypically different individuals, in contrast to environmentally induced differences which, as a rule, cause only temporary, nonheritable changes of the phenotype."
Alternation between a multicellular diploid and a multicellular haploid generation is never encountered in animals. [33] In some animals, there is an alternation between parthenogenic and sexually reproductive phases , for instance in salps and doliolids (class Thaliacea). Both phases are diploid.