Linnaeus

Family Tree Primer

Rather than go through the details of the Linnaeus classification system of animals, here we will use common animal names and a overly simplified reference to demonstrate relation in perhaps a overly generalized fashion: Let's follow the Wolf down the family tree, in particular; the North American "Timber Wolf" for this example. the table illustrates its relationship to: Kangaroo, Mankind, Pig, Cat, Bear, Fox, Dog, and other types of wolf.

Animals in the same Class	Animals in the same Sub-class	Animals in the same Super-Order	Animals in the same Order	Animals in the same Sub-order	Animals in the same Family	Animals belonging to the same Genus	Animals of the same Species	Animals of the same Sub-species
Timber Wolf	Timber Wolf	Timber Wolf	Timber Wolf	Timber Wolf	Timber Wolf	Timber Wolf	Timber Wolf	Timber Wolf
Artic wolf	Artic wolf	Artic wolf	Artic wolf	Artic wolf	Artic wolf	Artic wolf	Artic wolf
Dog	Dog	Dog	Dog	Dog	Dog	Dog
Fox	Fox	Fox	Fox	Fox	Fox
Bear	Bear	Bear	Bear	Bear
Cat	Cat	Cat	Cat
Pig	Pig	Pig
Man	Man
Kangaroo

As we go "down the stairs", in a general sense, the animals "common ancestor" goes farther in the past, and shared characteristics subtract. The first split here is from "Class" to Sub-Class, and differentiates placental mammals from marsupials, that "split" occurred approximately before or around when the dinosaurs became extinct. The next split: "super order" occurred early in the age of mammals (exactly when is outside the scope and objective here) point being: it was a VERY long time ago. There really isn't any bottom line time scale or formula for divergence at any branch of the tree. In this example, each split occurs in millions of years, and in this case: bear and dog families diverged only a few million years ago, had we used rhinos and horses, that family split might have been tens of millions of years farther back, with one rhino genera surviving intact since then. Again this is a generalization and over simplification of the evolutionary process. The point here is to give you a sense of scale and relation based on common ancestry and characteristics, and demonstrate that the Linnaeus system is based on characteristics that extend beyond appearance. .

Applying this same example to a common killifish: Fundulopanchax gardneri "Akure": In the below example the principle is the same, except the time scale is probably a little different with fish; fish as a whole are a older lot, so some splits may have occurred further in the past (again exact times are outside the scope here), and moreover a this species reproductive cycle might be faster in comparison (the time between generations), so differentiation may occur faster or slower, it all depends on environmental variables and pressures, reproductive rates and so on. Some species of mammals and fish, like the puma and carp can range over a wide area and variety of habitats and show very little variation throughout their range (they represent a adaptable or generic design with very little impetus to specialize/diverge). Other species like the wolf (in the first example) can have 2-3 subspecies in the same state, and similiarly: many killifish of the same species can vary greatly in appearance (or breeding difficulty) from one body of water (population/location) to another. This is why killifish enthusiast place so much emphasis on maintaining a chain of "custody" for the original collection location, and going through great lengths to maintain the purity of the assorted strains even within the same sub-species

Animals in the same Class	Animals in the same Sub-class	Animals in the same Super-Order	Animals in the same Order	Animals in the same Family	Animals belonging to the same Genus	Animals of the same Species	Animals of the same Sub-species	Location
GAR "Akure"	GAR "Akure"	GAR "Akure"	GAR "Akure"	GAR "Akure"	GAR "Akure"	GAR "Akure"	Clauseni	Akure
GAR "N'Sukka"	GAR "N'Sukka"	GAR "N'Sukka"	GAR "N'Sukka"	GAR "N'Sukka"	GAR "N'Sukka"	GAR "N'Sukka"
Blue Gularis	Blue Gularis	Blue Gularis	Blue Gularis	Blue Gularis	Blue Gularis
Pearlfish	Pearlfish	Pearlfish	Pearlfish	Pearlfish
Guppy	Guppy	Guppy	Guppy
Tetra	Tetra	Tetra
Perch	Perch
Gar

So while all this jargon and information may seem irrelevant at first to the new or part-time hobbyist, it provides some background and/or relevance the first time you attempt to apply the same husbandry or breeding procedures to two seemingly identical/similar killifish (the different strains of Aphyosemion elberti, Austrolebias nigripinnis, and even some of the Fundulopanchax gardneri strains come to mind). It may not be important for one to fully understand the "evolutionary process", but you should have a idea of scale when conversation turn from genera, to species to locations, or when you get a newly collected killifish and would like to know how it fits into the bigger scheme of things