Homology and errors

  title={Homology and errors},
  author={Andrew V. Z. Brower and M{\'a}rio C{\'e}sar Cardoso De Pinna},
A recent review of the homology concept in cladistics is critiqued in light of the historical literature. Homology as a notion relevant to the recognition of clades remains equivalent to synapomorphy. Some symplesiomorphies are “homologies” inasmuch as they represent synapomorphies of more inclusive taxa; others are complementary character states that do not imply any shared evolutionary history among the taxa that exhibit the state. Undirected character‐state change (as characters optimized on… 

Homology and misdirection

  • J. Farris
  • Biology
    Cladistics : the international journal of the Willi Hennig Society
  • 2014
Hennig (1966) recognized symplesiomorphies as homologies, and that view is logically correct under the concept of homology (homogeny) prevalent among evolutionists since 1870, and so discarding the purported equivalence of homological and synapomorphy can be avoided.

Assessing similarity: on homology, characters and the need for a semantic approach to non‐evolutionary comparative homology

  • Lars Vogt
  • Biology
    Cladistics : the international journal of the Willi Hennig Society
  • 2017
A procedure for recognizing comparative homologues that lacks these problems and that utilizes a semantic framework is suggested, which substantially increases the analytical accessibility of comparative research and represents an important contribution to the theoretical and methodological foundation of morphology and comparative biology.

Homology assessment in parsimony and model‐based analyses: two sides of the same coin

  • Leandro C. S. Assis
  • Biology
    Cladistics : the international journal of the Willi Hennig Society
  • 2015
Although parsimony and model‐based analyses usually achieve concordant topological results, they may generate discordant inferences of character evolution from the same datasets, indicating that method selection has serious implications for evolutionary scenarios and classificatory arrangements.

Molecular homology and multiple-sequence alignment: an analysis of concepts and practice

This work presents examples of molecular-data levels at which homology might be considered, and proposes terminology with which to better describe and discuss molecular homology at these levels, and sheds light on the multitude of automated procedures that have been created for multiple-sequence alignment.

Homology and synapomorphy‐symplesiomorphy—neither synonymous nor equivalent but different perspectives on the same phenomenon

  • S. Richter
  • Biology
    Cladistics : the international journal of the Willi Hennig Society
  • 2017
I, however, do not consider the concept of homology equal or synonymous to that of synapomorphy and symplesiomorphy, as they represent different perspectives on the same phenomenon, i.e. correspondence by common origin.

About nothing

In light of recent terminological controversy, this article reviews cladistic conceptions of character states coded as absences, symplesiomorphies, and secondary losses. The first section addresses

Should the terms 'basal taxon' and 'transitional taxon' be extinguished from cladistic studies with extinct organisms?

It is shown how statements that are in accordance with the cladistic method can substitute both terms in order to avoid pointless or misleading information.

The jazz of cladistics*

In this metaphorical ‘composition’, nine ‘dissonant chords’ related to the drowning out of cladistic performance are commented on, including the false assumption of the irrelevance of classification and clashes amongst cladists themselves.

Are homology and synapomorphy the same or different?

In this letter, some points explored by Brower and de Pinna (2012) are reviewed, and it is shown why their alternative definition of homology cannot totally accommodate homology and synapomorphy as synonymous.

Less on homology

A binary perspective on homology is offered, a matter of comparison of two character states among two or more taxa, and taxa outside the realm of comparison have no logical bearing on the decision unless they are part of the most recent descendancy.



On homology

A global definition of homology is proposed, which discusses whether there is a difference between molecular homology and morphological homology, character stateHomology, nested homology (additive characters, and serial homology), and concludes by proposing a global definition.

Homology as a parsimony problem: a dynamic homology approach for morphological data

I explore the testing of alternative hypotheses of morphological correspondences in a quantitative cladistic context, and proposes a Bremer support for anatomical interpretations when the specific interpretation is not used.


Logical equivalence between the notions of homology and synapomorphy is reviewed and supported, and a general theoretical solution is proposed to determine evolution of characters with ambiguous distributions, based on the notion of maximization ofHomology propositions.

Inference of molecular homology and sequence alignment by direct optimization.

Confusing homologs as homologies: a reply to “On homology”

It seems that systematists, taxonomists, historians and philosophers of biology, perhaps all biologists and palaeontologists, never tire of discussing, expanding and redefining the homology concept.

On Homology and the Ontological Relationship of Parts

This approach suggests thatsynapomorphy is not equivalent to homology but rather that synapomorphies are hypotheses of homology (otherwise phylogenetic analysis is tautological), and that interorganismic homologies must be studied by other methods, primarily ontogenetic ones.


By dividing de Pinna's term primary homology into topographical identity and character state identity, this work emphasizes the sequential refinement of putative homology statements.

The types of homology and their significance for evolutionary biology and phylogenetics

This paper comments on recently revived discussion about the most adequate definition of homology and the significance of all four types for evolutionary biology and phylogenetic analysis is outlined.

The Place of Ancestor-Descendant Relationships in Phylogeny Reconstruction

It is concluded that autapomorphies can not refute ancestor-descendant relationships, and ancestor- descendant relationships based on morphology are not objective statements when applied to fossil populations or species.

The meaning of “phenetic”

  • A. Brower
  • Biology
    Cladistics : the international journal of the Willi Hennig Society
  • 2012
Sir, A recent broadside critique of quantitative cladistic methods in ichthyology by Mooi and Gill (2010) applied the labels phylophenetics and phenetic cladistics to cladistic analytical approaches