A group of lobsters are enclosed within a tank, representing what a population is, a group of organisms that are able to interbreed, and are located in the same place, at the same time. Often populations will be distinguished from one another through particular, certain attributes; such as, sex ratio, mortality rate, growth rate, and age structure. Populations will have often a particular biotic potential, if the environmental condition was optimal. However nothing is perfect on planet Earth, and populations will be measured by their carrying capacity, as a population will often be hindered by food, water availability, climate, disease, and so on. Furthermore, one may find density-dependent factors, such as an abundance of organisms in a small area, or density-independent factors, like rain, temperature, and so on. Populations will often compete against each other to obtain resources, harming each other at times and even the environment. Moreover, populations is the lowest level at which evolution may occur. As can be seen, populations are quite intriguing and necessary to understand to comprehend the interconnectedness of the biology hierarchy.