View source for Species Definition

=Abiotic Species Concept=
This is only my own view and is not shared by many biologists. Species do not exist in biological reality; it is only a label/tool used by people to talk about living organisms. There is a strong correlation between many biological principles, morphological differences, boundaries to gene flow, shared ancestry, etc. between what are commonly viewed as species by humans and collections of biological organisms. This has led to attempts to unite the two and define species in biological terms, but ultimately this approach fails to be universal. This is not to say that the concept of a species does not have value. It is a tool that helps us in management and conservation decisions. However, we should accept that the relationship between human defined species and collections of biological organisms is imperfect.

...to be continued. I will also add some other types of species concepts here.