Pre-zygotic Mechanism

Pre-zygotic Mechanism i. Ecological isolation or habitat isolation – the members of the same population may be separated from one another by a differences in their habitat. For example Rana areolata occupies burrows dug by mammals and tortoises during the day and breeds in grassy shallow ponds whereas Rana grylio breeds in deep waters. Due to the difference in their habitat the two species are able to maintain their respective species identities.

Evolution domestica ) that grew in the same area. This small group of apple maggot flies selected a different host species from the rest of the population and its offsprings became accustomed to domesticated apples. Phenotypic plasicity is the ability of single genotype to produce more than one phenotype. When this plasticity is expressed seasonally in planktons, it is referred to as cyclomorphosis.