Main Factors Responsible For the Rise of New Species.
Factors responsible for the formation of a new species:
Natural selection: All populations respond to changes in their environment. Individuals will respond in different ways depending on their genes. Those individuals whose genes are best suited to the environment are more likely to survive and pass on their genes to the next generation.
This is natural selection. Gradually, favorable genes will start to predominate in the population and less favorable genes will decline.
Genetic drift: It is caused by drastic changes in the frequencies of particular genes by chance alone. Genetic drift with changes in the gene flow imposed by isolation mechanism acts as an agent of specification which ultimately results in evolution.
Geographical isolation: Geographical isolation is caused by various types of barriers such as mountain ranges, rivers and seas. It leads to reproductive isolation due to which there is no flow of genes between separated groups of population which ultimately results in specification.