Systematics and Taxonomy, Essay Example

In the early years of numerical taxonomy, advocates of the approach claimed that the methodology would bring objectivity to systematics by the application of highly quantitative techniques, specific algorithms for clustering, and numerical assessment of similarity. What do you make of these claims of objectivity?

The acclaim of the taxonomists in relation to the classification of species according to particular methodology to determine objectivity is the most appropriate method in sciences. The objectivity is attained by grouping taxonomical objects on the basis of similar morphological and physiological attributes. The grouping ensures similar biological things under a class useful to study the evolution and other gross characteristics. The nomenclature is designed in such a way that a single glance describes the physical characteristics as a tool of identification.

An underlying assumption of numerical taxonomy is that overall similarity is a reliable indicator of evolutionary relationships (i.e., recency of common ancestry) among organisms. Is this a reasonable assumption?

Organisms of the same evolution are believed to possess certain similarities in morphology and physiology. The underlying assumption of taxonomy of grouping similar organisms under a common ancestry is therefore a reliable characteristic as long as the similarities overweigh the distinctions on a large scale since many times organisms are wrongly placed on very few similarities.

If numerical taxonomy is such a flawed method for inferring evolutionary relationships, why are we torturing you with all this? (Actually, this is a serious question: Do you believe that cluster analysis might be of use in other areas of biology? If so, in what fields, and how?)

Though cluster analysis is not a perfect method of classification in taxonomy, it is in practice in biology in wider areas like transcriptomics, genomics, human genetic clustering and sequence analysis. The reason of choice in these areas owes to simplicity of use in large databases.

The results of phenetic and cladistic analysies are inherently hierarchical, as is the branching sequence of the evolution of organisms. So, too, is the Linnaean classificatory system of ever more inclusive taxonomic categories from species, Genus, Family, Order, Class, Phylum, Kingdom and Domain. Can you name some other hierarchical classification systems (not necessarily biological)?

Other hierarchical classification systems other than taxonomical include classification of rivers, roads (Functional road hierarchy, administrative road hierarchy), soils (USDA soil taxonomy, FAO soil classification), libraries, databases, computer languages.

Taxonomists were erecting classifications of organisms long before Darwin convinced biologists of the reality of evolution. Some of these taxonomists believed in the fixity of species and in special creation. Nevertheless, in some respects, these pre- Darwinian classifications are rather similar to those produced later by evolutionary taxonomists. Why do you think this is so?

Similarity is reported in the pre Darwinian classifications is reflected even in modern classification systems as the major principle followed in the evolutionary classifications as all of these classifications were based either on similarities of morphology, phylogenies, phyto-chemical characteristics and application of various numerical methods.