Homology can't be evidence of ancestry if it is defined thus (Talk.Origins)

Claim CB810:

Homology is defined as similarity due to common ancestry. The claim then that it is evidence for common ancestry is a circular argument.

Source:
 * Wells, Jonathan, 2000. Icons of Evolution, Washington DC: Regnery Publishing Inc., pp. 63-65.

CreationWiki response:

If one starts reading on page 59 instead of page 63 as Talk Origins says, it is obvious that Wells is well aware of the fact that the term homology predates Darwin and that it was not originally defined in terms of common decent. As a side note, it is interesting how Talk Origins takes issue with its own statement about Carolus Linnaeus being a creationist.

Furthermore Talk Origins claim that "Homology is not defined as similarity due to common ancestry" is wrong. It is often defined as such in classes and text books even if not formally defined as such. Even if similarity due to common ancestry is not the formal definition of homology, it is indeed the practical definition of homology. Before similarities between two organisms&mdash;regardless of how similar they are&mdash;are considered homologous by Evolutionists, they must first be considered to result from common ancestry.

A homologia não pode ser evidência de ancestralidade se estiver definida assim (Talk.Origins)