Answer to Question 1
Core societies are rich, powerful nations that are economically diversified and relatively free of outside control. Peripheral societies are poor and weak with highly specialized economies over which they have relatively little control. In world-systems theory, the core societies are said to profit from the exploitation of the peripheral ones.
Answer to Question 2
Modernization theory sees development as the natural unfolding of an evolutionary process in which societies go from simple to complex institutional structures and from primary to secondary and tertiary production.
The effects of aging can be seen in the decline in function of many physiological systems.
Global Stratification: Income of the World's Nations
Model of a complex systems
Cretaceous world
Difference-Between-Carbohydrates-and-Lipids-infographic
Difference of Squares