The following points highlight the three important species of Entamoeba for which man is host. The species are: 1. Entamoeba Histolytica 2. Entamoeba Coli 3. Entamoeba Gingivalis. Species # 1. Entamoeba Histolytica: It was discovered by a Russian zoologist, Friedrick Losch in 1875. This is an endoparasite common in man, apes and monkeys, and may also be found in pigs, [...]
In this article we will discuss about the modes and mechanisms of origin of species. Modes of Origin of Species: The main modes of speciation are: 1. Sympatric speciation: This is the origin of species without geographic isolation. Sympatric species originate by instantaneous development of isolating mechanisms within a deme. Once reproductive isolation is established each population follows its own [...]
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 [...]