Beginning of Essay
1. Explain why any one species cannot live everywhere. Any species cannot live everywhere because this would effect the natural balance. Also one species cannot adapt to all the different environments of our planet. For example a marine creature can only live unde ....

Middle of Essay
.... in a given space. Explain one method by which biologists can study population densities without obtaining such data. Scientist barely ever count the amount of individuals in a certain area because it would take too much time. Instead of actually counting the number of individuals in an area they would compare it with other areas where they know the population of individuals. In this way they can roughly estimate the number of individuals in a certain area. 4. What might happen to a rabbit population in an area where there are no predators? If there were a few rabbits in an area with no predators they would over-populate and cause serious damage ....