Populations
A population is made up of all of the individuals of a species in a given area at a certain time. Populations have genetic variations within themselves and between other populations. Genetic variations like hair color or size may differ from individual to individual. Also, not all members of the population are equal in their ability to survive and reproduce.
sources:http://www.physicalgeography.net/fundamentals/9d.html
sources:http://www.physicalgeography.net/fundamentals/9d.html