Notes:
From a broader perspective, we can summarize relations between homology, homogeny, and homplasy as follows.
For shared similarities differentially observed among individuals in different species, we implicitely or explicitely formulate causal questions in relation to facts in need of explanation.
The alternative theories most commonly applied have been that of the archetype, as in the case of Owen's work, or evolutionary theory, which uses descent with modification or common ancestry.
Regardless of the theory applied, the nature of the inference is abductive, leading to respective explanatory hypotheses. Hypotheses derived from the archetype theory should be referred to as homology, whereas hypotheses from evolutionary theory are in the form of homogeny and homoplasy.
By fully understanding the original foundations of these concepts, we might surmize that had Lankester's terminology been adopted early on, much of the confusion surrounding the interpretation and use of homology might have been avoided. To rectify the situation in the present simply requires that we acknowledge several conditions: the first being correct distinctions between Owen's and Lankester's views; the second being the fact that the subjects referred to in the definitions of homology, homogeny, and homoplasy are explanatory hypotheses associated with different causal theories; and lastly, that we must overcome the all too common practice of disregarding the requirement of total evidence in systematics.
