摘要：Morphometric and genetic analyses of a variety of living and fossil taxa 1-7 support the use of a probabilistic definitionof a species in the context of ‘sigma taxonomy’ (where sigma represents ‘S’ for spectrum 6,7 ), in contrast to alphataxonomy 8 , for which boundaries discriminating species are presumed to be distinct, thus accommodating onlyrigid, ‘either-or’ classification schemes.
关键词：morphometric analysis; genetic analysis; hybridisation;alpha taxonomy; biological species constant
