Philosophy in homology

According to Popper, the decision to give as true a hypothesis is only possible in the scenario where any other hypothesis refutes this truth; for Popper the way of approaching science is through the deductive method, where the hypothesis can be corroborated or distorted through observations (Helfenbein & Desalle, 2005)

In this context, the scientific community has criticized but also has applied the premise that a character used in comparative biology must comply with the Paterson test consisting of three tests; the first of similarity, the one of conjunction and finally the one of congruence (Patterson, 1988); to be denominated homology and in this way to be analyzed to find the relations of parentage between all the existing species.

According to Pinna (1991), "a homology in her basic form is understood as the equivalence of the parts", that is, the relation derived from the parts, which are homologous (Williams & Ebach, 2008)

Following the idea of corroboration proposed by Popper (1983), one can find the logical probability that a hypothesis (cladogram or diagram of ramifications that summarizes the general knowledge about the types and relationships of organisms (Platnick & Nelson, 1978)) is supported by evidence (homology) given background knowledge or background (Figure 1).

Figure 1. Equation of corroboration (Popper, 1983).

The above expression corresponds to Popper's corroboration definition, where p = probability, h = hypothesis, e = evidence, b = background, hb refers to the conjunction between h y b so p (e, hb) is the probability of the evidence given the hypothesis and the background; that is, of the conditional probability form P (A | B). Thus, the value of C is positive when the evidence supports the hypothesis, it is negative when the evidence does not contribute to the hypothesis and C = 0 when the evidence does not guide the hypothesis (Queiroz & Poe, 2001).

Is very important the clarity about the definition of homology because as a scientific community agreed to analyze the evolutionary tracks with the same lens; and we can share the Williams & Ebach (2008) statement that homology must be considered the unit of classification.

Bibliography

Helfenbein, K. G., & Desalle, R. (2005). Falsifications and corroborations : Karl Popper’s influence on systematics, 35, 271–280.

Patterson, C. (1988). Homology in Classical and Molecular Biology, 5(6), 603–625.

Pinna, M. G. G. De. (1991). Concepts and tests of homology in the cladistic paradigm, 367–394.

Platnick, N. I., & Nelson, G. (1978). A method of analysis for historical biogeography.

Queiroz, K., & Poe, S. (2001). Philosophy and Phylogenetic Inference : A Comparison of Likelihood and Parsimony Methods in the Context of Karl Popper ’ s, 50(3), 305–321.

Williams, D., & Ebach, M. (2008). Foundations of Systematics and Biogeography.