Such expressions as that famous one of Linnæus, and which we often meet with in a more or less concealed form, that the characters do not make the genus, but that the genus gives the characters, seem to imply that something more is included in our classification, than mere resemblance. I believe that something more is included; and that propinquity of descent,—the only known cause of the similarity of organic beings,—is the bond, hidden as it is by various degrees of modification, which is partially revealed to us by our classifications (Darwin, 1859, p. 413f).

Monday, 8 December 2008

Serializing our New Book: A Question of Relationship

David Williams and I have signed our contract for a new book to be published by Forrest Text. The book A Question of Relationship: the role of homology in systematics and biogeography (our working title) will be serialized on this blog over next few months (or until we get it written).

We hope that our book addresses some of the more important issues in systematics and biogeography, as well as getting your feedback. The task will be an arduous one as we hope to cover the following topics recently discussed in the literature and on this blog:
    Defining Relationship
    Bortoft's Intrinsic & Extrinsic Thinking in systematics and biogeography
    Complexity and Classification
    Homology versus Similarity
    Paraphyly and Monophyly
    Phenetics versus Natural Classifications
    Phylocode and Artificial Classifications
    Molecules and Morphology
    DNA Follies and the Thin Blue Line
We hope that this interactive experiment in science writing ends in a well rounded and balanced text. Let the writing commence!

3 comments:

Kevin Zelnio said...

Looking forward to it! I would be interested in a chapter about creating supertrees, those that combine data from several sources, like DNA, morphology, behavioral traits. How should one go about weighting different characters, a review of what has been argued for/against using all the available evidence, gene only phylogenies, morphology-only, etc. How is homology dealt with in either cases. Perhaps that is another book in and of itself!

Wills Flowers said...

I'm also looking forward to it. I hope you discuss some studies of real organisms done they way you argue they should be done (TTS, using a Goethean approach). Or are such studies yet to be done?

Malte C. Ebach and David M. Williams said...

We will try to cover as much as possible, however, detailed discussions on super-trees, which combine morphological and molecular data, have already been covered in more detail elsewhere. For instance, see Williams in Bininda-Emonds (2004). The above would certainly fill up another book - including studies of real organisms! Also, smaller studies using TTS have been made (e.g., Ebach,& McNamara, 2002; Williams, 1996).

We wish to investigate how systematists and biogeographers think in terms of relationship. By defining relationship, I believe we will be able to make sense of the issues currently discussed in the literature. Why, for instance, do some people believe that paraphyletic groups are relevant? We think it has to do with another interpretation (i.e., way of thinking) of 'relationship'. Systematists always use the term relationship but it is rarely ever defined. This is why, for instance, there are two incompatible definitions of monophyly - each represents a different way of thinking.

References
Ebach, M.C. & McNamara, K.J. (2002). A systematic revision of the family Harpetidae (Trilobita). Records of the Western Australian Museum, 21:235-267.
Williams, D.M. (1996) Fossil species of the diatom genus Tetracyclus (Bacillariophyta, `ellipticus' species group): morphology, interrelationships and the relevance of ontogeny. Philosophical Transactions of the Royal Society of London, 351: 1759–1782.