Transformation Series as an Ideographic Character Concept.

Area of Science:

• Phylogenetic Systematics
• Evolutionary Biology

Background:

• Phylogenetic inference relies on understanding characters.
• Hennig's concept of characters as transformation series is often overlooked.
• Similarity-based concepts are frequently used instead of Hennig's proposal.

Purpose of the Study:

• To explicate Hennig's definition of character as an ideographic concept.
• To clarify the relationship between homology and synapomorphy.
• To address concerns regarding character dependence in phylogenetic analysis.

Main Methods:

• Conceptual analysis of Hennig's definition of character.
• Distinguishing historical identity (homology) from discovery operations.
• Evaluating character dependence in the context of phylogenetic systematics.

Main Results:

• Characters, as transformation series, are historical individuals.
• Homology signifies a historical identity relation, not synapomorphy.
• The distinction between primary and secondary homology is invalid.
• Character dependence concerns should focus on historical independence, not correlation.

Conclusions:

• Hennig's ideographic concept of character is fundamental for phylogenetic inference.
• Understanding characters as historical individuals is key to accurate systematics.
• Properties defined by intention or extension are unsuitable for character individuation in phylogenetic analysis.