How Do We Define Species?
History, semantics, and academia
In a recent piece, I covered the basics of evolution. Check it out:
In it, I claim that not all biologists define species the same way. Oxford Dictionary defines a species as “a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial, e.g. Homo sapiens.”
This is the Biological Species Concept, this idea of gene exchange — which is to say, interbreeding and producing fertile offspring. It’s far from the only concept, but it’s probably the most popular.
It’s not perfect. It’s basically useless unless you’re able to observe interbreeding in a population, or otherwise able to compare genes. It’s useless for fossilized remains, which is our major tool for knowing life across time.
Consider how the diversity of life has been studied, catalogued, and discussed, historically. Local organisms — those visible with the naked eye, or the eye unaided by microscopes — were known through common familiarity, through cultural knowledge, mainly of what lifeforms were edible versus poisonous. (Sorting plants into…
