homology and analogy

[ffclrp - biolog.6331010 340]

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
CEP 14001-970
Ribeirco Preto, SP, Brasil

Fone, Fax: 016 6371999
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