Cladistic biogeography and the art of discovery

Authors: Ebach, Malte C.1; Humphries, Christopher J.2

Source: Journal of Biogeography, Volume 29, Number 4, April 2002 , pp. 427-444(18)

Publisher: Wiley-Blackwell

Buy & download fulltext article:

OR

Price: $48.00 plus tax (Refund Policy)

Abstract:

Aims

Cladistic biogeography is about discovering geographical congruence. The agreement of several taxon-area cladograms (TACs) rarely yields a perfect result. Areas may overlap, taxa may not be evenly distributed, and thus, ambiguity may be prevalent in the data. Ambiguity is incongruence and may be resolved by reducing paralogy and resolving potential information. Recently, several new approaches in cladistic biogeography [i.e. Brooks parsimony analysis (BPA), Assumption 0] interpret ambiguity as congruence. These methods are problematic, as they are generational. Methods constructed under the generation paradigm are flawed concepts that are immunized from falsifying evidence. A critique of modified BPA reveals that taking an evolutionary stance in biogeography leads to flaws in implementation. Methods

Area cladistics is a new development in cladistic biogeography. Area cladistics adopts paralogy-free subtree analysis using Assumption 2, to discover the relative positions of continents through time. Results

Geographical congruence is the result of allopatric (geographical) speciation. Vicariance, dispersal and combinations of both, are recognized causes for allopatric speciation. Area cladistics highlights the concept that all these events occur in response to geological changes (e.g. continental drift) either directly, by geographical boundaries, or indirectly, at the level of ocean currents. Samples of chosen examples all respond to the geological process. The examples include Ordovician–Silurian and Lower Devonian trilobites to yield a general areagram which is a representational branching diagram that depicts the relationships of areas. Main conclusion

Finding one common biogeographical pattern from several unrelated groups is a qualitative approach to interpret the positions of continental margins through time. Area cladistics is not a substitute for palaeomaps that are derived from palaeomagnetic data, but general areagrams adding to the body of knowledge that yields more precise interpretations of the earth's past.

Keywords: Area cladistics; Assumption 2; BPA; continental drift; generation and discovery paradigm; geographical congruence; palaeomagnetics; paralogy; sub-tree analysis

Document Type: Guest Editorial

DOI: http://dx.doi.org/10.1046/j.1365-2699.2002.00687.x

Affiliations: 1: School of Botany, The University of Melbourne Australia, 2: Department of Botany, The Natural History Museum, London, UK

Publication date: April 1, 2002

Related content

Tools

Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content

Text size:

A | A | A | A
Share this item with others: These icons link to social bookmarking sites where readers can share and discover new web pages. print icon Print this page