Answer to Question 1
In the late 1960s, MacArthur and Wilson published the Theory of Island Biogeography in which they posited that number of species on an island were positively correlated to island size, negatively correlated to island distance from the mainland (isolation), and that a dynamic equilibrium existed between species extinction and immigration, which were related to island size and isolation, respectively. Though they were discussing actual islands, they noted that these principles could be applied to fragmented landscapes, which were similar to islands. Though thinking on this matter has evolved greatly since the publication of the book, it is still considered a seminal book that laid the foundation for many of the modern principles of biological conservation.
Answer to Question 2
The subsurface area where the motion of seismic waves is initiated along a fault plane is the focus (or hypocenter). The area at the surface directly above the focus is the epicenter. An aftershock occurs after the main shock, sharing the same general area of the epicenter.
Female returning to the sea after nesting in Redang Island, Malaysia
This girl has a long leg cast, which was applied after surgery to correct her clubfoot.
Formation of Myelin
A medical assistant listening to the patient and physician discuss the patient's care.