6 public questions tagged with this topic.
Phylogenetic classification considers evolutionary relationships to group organisms.
Ref: NCERT Class 11 Biology Chapter 3: Plant Kingdom Pteridophytes - Structure and Life Cycle
The two-kingdom system did not distinguish prokaryotes from eukaryotes, unicellular from multicellular organisms, or photosynthetic organisms from non-photosynthetic fungi. Many organisms therefore did not fit properly into either Plantae or Animalia.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Five Kingdom Classification and Kingdom Plantae Animalia
R. H. Whittaker proposed the Five Kingdom Classification in 1969. The five kingdoms recognised in this system are Monera, Protista, Fungi, Plantae and Animalia.
Ref: NCERT Class 11 Biology Chapter 2: Biological Classification Five Kingdom Classification and Kingdom Plantae Animalia
Artificial classification groups organisms using one or very few conspicuous morphological traits arbitrarily selected such as growth habit herb shrub tree, flower colour, leaf shape or number of stamens as in Linnaean sexual system. It ignores overall affinity and converges unrelated plants sharing single trait creating polyphyletic assemblages. All characters approach describes natural system, DNA data phylogenetic modern molecular, phylogeny phylogenetic system based on common descent. Artificial systems easy to construct using keys but produce unnatural groupings, example Linnaeus 24 classes based on androecium counts. Serves convenient identification but fails to predict other characters, superseded by natural systems Bentham Hooker.
Ref: Simpson Plant Systematics, Artificial classification few characters Linnaeus sexual system
Empirical system primarily serves practical cataloguing purpose compiling floristic inventories, checklists, index herbariorum and local floras arranged alphabetically for quick lookup without implying natural relationships or phylogeny. It does not aim at true classification reflecting affinity nor evolutionary studies nor phylogenetic tree construction which require character analysis and homology assessment. Listing of flora in field guides often adopts empirical alphabetical arrangement by family or genus for user convenience especially when audience lacks taxonomic training. This utilitarian role explains its persistence despite scientific inadequacy for reflecting evolutionary affinity, serving documentation and accessibility not research hypothesis.
Ref: Lawrence Taxonomy Vascular Plants, Empirical listing flora; Radford Plant Systematics
Empirical classification represents most primitive arbitrary arrangement lacking natural affinity consideration, often organizing specimens alphabetically by genus name, by colour, size, medicinal use or collection sequence solely for convenience of reference and retrieval. It does not employ phylogenetic, anatomical or reproductive criteria as scientific basis. Thus classification based on alphabetical order exemplifies empirical. Such listings appear in early herbals, dictionaries and herbaria indices facilitating rapid lookup but conveying no evolutionary insight. Contrasts with artificial few characters, natural many correlated characters, phylogenetic common ancestry. Empirical approach still used for curation where natural order secondary.
Ref: Jones & Luchsinger Plant Systematics, Empirical classification alphabetical; NCERT
