Speciation can arise through abrupt events, such as changes in chromosome number, or as a consequence of adaptation to different ecological niches. What is the term for the splitting or diverging of a population into two or more species?

The correct answer is: Cladogenesis.

Explanation:

Cladogenesis can be defined as the evolutionary process by which two or more new species develop from a parent species simultaneously.This happens because of many reasons listed below:When the population of the species gets split in two regions due to the development of a geographical barrier in between them. Each sub-population adapt to the respective environments they are exposed to. If the environments are too varied, they tend to develop varied characteristics and eventually develop into two new species.Due to scarcity of their preferred resources in their habitat, some individuals may adapt themselves to utilise one type of resource which is abundant in their habitat while the other individuals may adapt themselves to some other resources also present abundantly in their habitat. Different resource adaptation can induce other drastic variations in the two sub-populations causing them to develop into two different species.