The following points highlight the six main factors that cause genetic divergence in species. The factors are: 1. Mutation 2. Recombination 3. Genetic Drift 4. Natural Selection 5. Hybridization 6. Polyploidy. Genetic Divergence: Factor # 1. Mutation: Gene mutations bring about genetic divergence. It is due to the changes in the chemical composition of gene by substitution, insertions, deletions and [...]
In this article we will discuss about the meaning and mechanisms of isolation of species. Meaning of Isolation: The first step in the development of a new species is isolation. A population should split up into two or more separate demes each with its own gene pool. These demes must be isolated from one another. If genes are exchanged between [...]
The following points highlight the top six theories regarding the origin of metazoa. The theories are: 1. Syncytial-Ciliate Theory 2. Colonial Flagellate Theory 3. Colonial Blastea and Planula Theories 4. Gastraea Theory 5. Monophyletic Origin of Metazoans 6. Polyphyletic Origin of Metazoans. 1. Syncytial-Ciliate Theory: The origin of metazoans probably took place through the growth, nuclear division and cellularisation of [...]