Geology- a unifying theory gives us one broad explanation for a number of phenomena where, previously, we needed separate explanations. how does the plate tectonics theory serve as a unifying theory?

The plate tectonic theory is considered to be a unifying theory. According to this theory, the earth's crust is made up of numerous small and large pieces of lithospheric plates. These lithospheric plates are of 2 types, namely the continental crust and the oceanic crust. These plates continuously flows over the less dense layer of the asthenosphere due to the convection current that generates in the mantle. This current initiates because of the heat radiated from the interior of the earth. The main mechanism for the plate motion was determined later and this theory proved the continental drift theory that was not able to explain the main mechanism for the drifting of the plates.

This theory describes how the plates on earth were once all together and how they were separated with time, causing various changes and formed various types of landforms, shaping the earth's surface.

d. stage 4

explanation:

the existence of some kind of demographic transition is widely accepted in the social sciences because of the well-established historical correlation linking dropping fertility to social and economic development.[1] scholars debate whether industrialization and higher incomes lead to lower population, or whether lower populations lead to industrialization and higher incomes. scholars also debate to what extent various proposed and sometimes inter-related factors such as higher per capita income,lower mortality, old-age security, and rise of demand for human capital are involved.[2]