Here's why:
* Species: The basic unit of classification in biology. A species is defined as a group of organisms that can interbreed and produce fertile offspring.
* Interbreeding: The process of two individuals from the same species mating and producing offspring.
* Fertile Offspring: Offspring that are able to reproduce themselves.
This definition helps distinguish between different groups of organisms. For example, a dog and a wolf can interbreed, but their offspring (a wolfdog) is usually fertile. This suggests that dogs and wolves are closely related and might be considered the same species, although there is still debate among scientists about their specific classification.
