homology and analogy

[John Grehan]

Comment in response to Thomas Schlemmermeyer on homology

It seems to me that behind all the technical arguments over the subject,
homology is
something that is considered informatitve (about origins, process etc), and
analogy
(or any other term such as homoplasy etc) is not.

Sincerely, John Grehan


>Dear taxacomers,
>
>I have a small problem:
>I got confused with the use of the terms homology and analogy.
>
>So far, I believed in the existence of horizontal and vertical
>homologies.
>Vertical homologies are the homologies most commonly
>observed in literature. They are due to common ancestry.
>
>However, I believed as well in the existence of horizontal
>homologies. They arise because of interorganismal transfers
>such as gene transfer, learning, culture and so on.
>For me, it is quite natural to use the term homology in such
>cases as well.
>But, I am aware that in the cladistic paradigm such homologies
>turn up as homoplasies.
>
>And, to turn everything more complicated, sometimes the scientists
>use the term analogy.
>I think an analogy would be some kind of functional similarity
>of a given structure.
>But, I know cases where scientists undoubtedly apply the term analogy
>to supposed (though unproven) horizontal homologies.
>
>Someone wants to discuss this item?   Thomas
>
>
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>Thomas Schlemmermeyer
>Museu de Zoologia, Universidade de Sco Paulo
>Caixa Postal 42694
>CEP 04299-970
>Sco Paulo, SP, Brasil
>
>Residjncia:
>Thomas Schlemmermeyer
>Caixa Postal 00276
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>
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