This definition above refers to the geographic isolation.
It means exactly what it says in the definition - one species is left behind from the rest of the population, and it stays in that particular location, evolving and changing from the species and population it was once a part of.
The landscape in which limestone is eroded to form deep valleys and cavers are called Karst landscape or karst topography. This kind of development start occuring whenever the acidic water starts breaking down the bedrocks near the cracks. As the bedrock starts breaking down slowly, the cracks start to open up creating bigger holes. with passage of time the holes will become big enough to create an underground drainage system for the surface water to flow and form underneath. If the water is unable to flow out and becomes stagnant, then the Karst will start getting bigger.
Typhoid fever is most common in non-industrialized countries. Travelers to Asia, Africa, Eastern Europe, and Latin America are especially at risk. Salmonella typhi bacteria are shed in the urine or stool of infected persons, including chronic carriers. There are no known animal reservoirs for typhoid fever.
Im pretty sure that it is (A) because blood pumps to get every where through your body. If it didn't one half of your body would feel cold or numb.
An organism that makes its own food is a producer.