Consensus in the search for areas of endemism

AAGESEN, L.; SZUMIK, C.; GOLOBOFF, P.

JOURNAL OF BIOGEOGRAPHY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2013 vol. 40 p. 2011 - 2016

0305-0270

For ambiguous data sets, methods to determine areas of endemism based onan optimality criterion may result in large numbers of candidate areas, andthus some kind of consensus technique is required to summarize those results.This paper presents a formal description of two possible algorithms or rulesfor area consensus, which merge candidate areas if they share a user-definedpercentage of the species that define each candidate area. The two consensusrules summarize ambiguity in different ways. Applying the ?tight? rule willresult in consensus areas defined by species present in nearly all cells, but incases where there is significant conflict the result may be a high number of distinct consensus areas. The ?loose? consensus rule is more agglomerative and willresult in fewer consensus areas, combining areas when overlapping distributionpatterns exist. Depending on the aim and scale of the analysis, the two consensus rules can be used either to delimit areas of endemism with sharp boundaries or to identify diffuse and gradually replacing biogeographical patterns. These two different approaches are discussed and demonstrated using real data.