The process of change in the species structure over time is called ecological succession. Ecologists defined two types of succession primary succession and secondary succession.
In primary succession, a new land or rock is colonized first time by living organism. In secondary succession, communities start establishing an area again in which most or all communities eradicated due to some disturbance.
For example, some abandoned fields growing back into the forest which was disturbed by human interference. So the correct answer is secondary succession.
Identical twins share all of their genes and are always of the same sex. In contrast, fraternal, or dizygotic, twins result from the fertilization of two separate eggs during the same pregnancy. They share half of their genes, just like any other siblings.
