About nothing

  title={About nothing},
  author={Andrew V. Z. Brower and M{\'a}rio C. C. Pinna},
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 absence as a question of ontology vs. epistemology. The second and third sections address the evidentiary status of symplesiomorphy in cladistics, the fourth contrasts primitive absence with secondary loss, and the fifth clarifies the meaning of “grouping”. While secondary losses (reversals) are… 

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.

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.

What is a cladogram and what is not?

  • A. Brower
  • Biology
    Cladistics : the international journal of the Willi Hennig Society
  • 2016
The origins and meanings of “cladogram” are reviewed and numerous recent authors treat it as synonymous with “dendrogram” and do not appreciate the particular methodological connotations of the former term.

Patterns of character evolution in phylogenies

The main purpose in this letter is eliminating redundancy and increasing precision in the description of the patterns of character evolution in phylogenies, i.e., apomorphy and plesiomorphy.

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.

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.

Impact of errors on cladistic inference: simulation-based comparison between parsimony and three-taxon analysis

Parsimony is shown to be more efficient with numerous character states (more than four), and 3ta to beMore efficient with binary characters, both methods being equally efficient with four states per character.

Dealing with propositions, not with the characters: the ability of three-taxon statement analysis to recognise groups based solely on ‘reversals’, under the maximum-likelihood criteria

It is demonstrated that groups based solely on putative reversals are always recognisable after maximum-likelihood analysis of three-taxon statement matrices, even without a priori recoding of the putative reversal states as new character states or fractional weighting ofThree- taxon statements.

Analyzing the Impact of Conflictive Dental Characters on the Phylogeny of Octodontoid Rodents

  • A. Candela
  • Biology
    Acta Palaeontologica Polonica
  • 2015
The results indicate that reanalyses of conflictive dental characters, scrutinizing data matrices, are particularly necessary to evaluate the current controversy on the phylogeny of octodontoids.

Experimental systematics: sensitivity of cladistic methods to polarization and character ordering schemes

The results of simulations of the evolution of phenotypic traits under a Brownian motion model are presented to characterize differences in sensitivity between parsimony and 3ta to outgroup branch length, which affects the reliability of ancestral character state estimates, (2) character state ordering scheme, and (3) ingroup branch lengths that reflect the geological age of studied taxa.



Homology and errors

An alternative definition of homology is proposed and primary and secondary homology are defended as realistic representations of discovery procedures in comparative biology, recognizable even in Direct Optimization.

Monophyly, Paraphyly, and Natural Kinds

This essay proposes to conceptualize the hierarchy of higher taxa is terms of a hierarchy of homeostatic property cluster natural kinds in terms of cladistic methods of phylogeny reconstruction.

Congruence and language

In cladistic biogeographical and systematic theory, synchronic and diachronic statements of relationships conflict in their interpretation of non-congruence.

“Pattern cladistics” really means paraphyly

  • J. Farris
  • Biology
    Cladistics : the international journal of the Willi Hennig Society
  • 2014
EWT’s purpose in all this, remarkably, is to rationalize reverting to an archaic system in which paraphyletic groups can be passed off as “monophyletic”.

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.

Pattern taxonomy

  • J. Farris
  • History
    Cladistics : the international journal of the Willi Hennig Society
  • 2013
In the course of reacting against Hennig and cladists, Williams, Ebach, and their allies have advanced a variety of remarkable claims, but most are pure fabrications, and some recent papers are devoted to exposing those deceptions.

Ontogeny, Phylogeny, Paleontology, and the Biogenetic Law

The biogenetic law is restated in a falsifiable form: given an ontogenetic character transformation, from a character observed to be more general to a character observation to be less general, the more general character is primitive and the less general advanced.


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.

Logical basis for morphological characters in phylogenetics

  • P. Sereno
  • Biology
    Cladistics : the international journal of the Willi Hennig Society
  • 2007
It is concluded that characters are simply features expressed as independent variables and character states the mutually exclusive conditions of a character.

Counterfeit cladistics

  • J. Farris
  • Physics
    Cladistics : the international journal of the Willi Hennig Society
  • 2012
It is pointed out that symplesiomorphies can be homologies, so that Patterson (1982) was wrong to equate homology with Hennig s (1966) synapomorphy, and the argument by which Patterson tried to rationalize his position is addressed.