Cladistic hypotheses

[J. Kirk Fitzhugh]

At 09:05 AM 11/23/2005 -0800, you wrote:
>The distribution of character states amongst the array of taxa being
>studied is data.  It is discovered by observation and is true regardless
>of the method of analysis.

Actually, the 'character states' are effects one wishes to explain by way
of common ancestry. The distributions of those states are not necessarily
true, since what is being referred to are observation statements, which are
fallible.

>   The cladogram resulting from a phylogenetic analysis may falsify or
> tend to support a hypothesis of homology or homoplasy underlying the
> distribution of a given character state.

Technically, a cladogram cannot falsify any observation statement,
especially given that those observation statements function as part of the
premises upon which the cladogram is inferred.

Kirk

-----------------------------------------------------
J. Kirk Fitzhugh, Ph.D.
Curator of Polychaetes
Invertebrate Zoology Section
Research & Collections Branch
Los Angeles County Museum of Natural History
900 Exposition Blvd
Los Angeles CA 90007

Phone:   213-763-3233
FAX:     213-746-2999
e-mail:  kfitzhug at nhm.org
http://www.nhm.org/research/annelida/staff.html
http://www.nhm.org/research/annelida/index.html
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