The following points highlight the three important species of Trichomonas for which man is host. The species are: 1. Trichomonas Vaginalis 2. Trichomonas Hominis 3. Trichomonas Tenax. Species # 1. Trichomonas Vaginalis: This is largest of three trichomonads of man. It averages about 13 um in length. The undulating membrane usually reaches to the middle of the body, but it [...]
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 [...]