PHYLETIC VERSUS PHENETIC APPROACH OF CLASSIFICATION: A CASE STUDY FROM FAMILY EUPHORBIACEAE

摘要

Phenetic as well as Phyletic, are both objective classifications, but are based on different dicta. One is based on overall similarities, and other on evolutionary characters. It is a matter of arguments, which one is more predictive and natural. Sometaxa of Euphorbiaceae have been taken as example to see, which one is better. One of the basic aim of classification is to produce a more natural and predictive classification which is based on more characters. These general purpose classifications aregood for most purposes, and they are reasonably represented by the familiar sequences of families, genera and species etc. which appear in Flora. There are situations when predictivity is not the only requirement, it is the relationship of a group of thetaxa. Theoretically Phylogenetic classifications can be considered as less natural than Phenetic ones, since they are based on only few but phylogenetically important characters. From a long time it is a matter of arguments whether phenetic or phyleticclassifications are more predictive and natural. What difference lies between classifications erected according to the two stand point, and investigating the reasons for and consequences of any difference found.