TYPES OF TAXONOMIES
For the suitability in studies various categorisations has
been done in taxonomy.
The important taxonomies are as follows
1. Numerical Taxonomy
It is carried out by quantitative assessment of
similarities and differences in order to make objective
It is now easily carried out using
assessments.
computers based process on all observable
characteristics. Number and codes are assigned to all
the characters and the data are then processed. In this
way, each character is given equal importance and at
the same time hundreds of characters can be
considered.
2. Cytotaxonomv
Cytotaxonomy is based on cytological information like
chromosome number, structure, behaviour and type of
chromosomes. For example,
(i) Chromosome number is constant for a species,
e.g., 46 in man, 48 in apes and potato, —0 in
maize, 16 in onion and 8 in Drosophila.
(ii) Behaviour of chromosomes was used by
taxonomists during pairing and banding
patterns to understand the relationships between
species, e.g., origin of humans from apes, origin
of wheat, etc.
3. Chemotaxonomv
It is the system based on the evidences from chemical
constituents (enzymes. hormones, proteins, amino acids,
some specific chemicals (usually secondary metabolites) and the
chemical nature of proteins have bcen utilised to establish
similarities and relationships. For example. the presence of
raphides has bcen found to bc common in 3 S families of plants.