Sure, classification is a language construct. A convenience. A way of describing things.
Giving things new or different names makes no difference to the truth of what they actually are.It's important to understand that before you tackle the fact that scientists are always quibbling over what a species is, and whether they've found a new one, and how many there are. If you don't get that they're only talking about what to call things, it might seem like there is uncertainty about
what things actually are.
There isn't. We know a great deal about who is related to who, and how, and how long ago they shared a common ancestor, mostly because of DNA, which mutates at a fairly predictable rate.
A "species" is generally considered a reproductively isolated group: an organism that can only reproduce with others of the same type. That definition doesn't necessarily work for everything (plants and asexually reproducing organisms, for example), but it's a good starting point.
When a number of different species are descended from a common ancestor fairly recently, like for example dogs, wolves, foxes, badgers, weasels, jackals, etc. that entire group also gets its own name. In this case,
Canidae. That's called a family. In between, there is a level called genus, where you've got all the wolf species, all the dog species, all the fox species, etc. grouped together. The common ancestry within these groups is more recent than the rest of the family, so the morphological differences are smaller.
Above the family, reaching even further back, you have other levels of common ancestry with an ever increasing number of other species at different times in the past.
And so it goes, like this:
Pro memory tip: "Keep Plates Clean Or Family Gets Sick".(You don't really need to remember Life or Domain - there are only 3 domains, and 1 "life")
The idea is, every level here represents common genetic ancestry with other species, with the most recent speciation at the bottom and the most ancient at the top.
Originally, before we had access to DNA evidence, which provides incredible refinement to our understanding of how things are related, we went by morphological similarity. We now understand better than ever
what things actually are, so what we call them shifts around as new evidence arises.
To use the example of dogs, the classification would be like so:
Life - (everything)
Domain - Eukarya (multi-cellular organisms)
Kingdom - Animalia (all animals)
Phylum - Chordata (animals with spines)
Class - Mammalia (all mammals)
Order - Carnivora (all meat-eating mammals)
Family - Canidae (all dog-like creatures)
Genus - Canis (all dogs)
Species - Canis familiaris (all domestic dogs)
