Transcript methods-of-classification-kingdom

3 Most Popular Methods in Classification
•Evolutionary Systematics
Ernst Mayr; G.G. Simpson
phylogram
•Phenetic Systematics
Camin, Sneath, and Sokal
phenogram
•Cladistic Systematics
Willie Hennig
cladogram
Evolutionary Systematics
•Evolutionary systematics gives illustrations of the
actual evolution of one species or higher taxon into
another.
•The method of reconstructing the evolutionary
history (phylogeny) of a taxon by analyzing the
evolution of major features along with the distribution
of both SHARED PRIMITIVE and SHARED
DERIVED characteristics
Phenetics
•Also called numerical taxonomy
•Phenetics is a school of taxonomy that classifies
organisms on the basis of overall morphological or
genetic similarity
•This mainly involves observable similarities and
differences irrespective of whether or not the
organisms are related
•It involves grouping types together in clusters; types
with many close relatives would be in a cluster
•Unlike cladistics no attempt is made to distinguish
between primitive from specialized (derived)
characteristics.
Cladistics
(Phylogenetic Systematics)
•Cladistics - also called Phylogenetic Systematics or
Phylogenetic Taxonomy - is a method of classifying
organisms by common ancestry, based on the
branching of the evolutionary family tree
•Based strictly on determining branching points in the
ancestry of organisms, it establishes groups based on
their shared, derived features, while ignoring primitive
features inherited from ancestors
•Organisms that share common ancestors (and therefore
have similar features) are grouped into taxonomic groups
called clades
Practices under Taxonomy:
1. Identification
2. Classification
3. Nomenclature
Characteristics of a Good Classification System
1. Universally accepted
2. Reflect real biological relationships
Ultimate Purpose of Systematics
“Provide a classification system that shows
how biological diversity (past, present,
and future) can be correlated into one
another through evolutionary events and
processes and that in turn provide basic
knowledge on other fields of science such
as agriculture, ecology, medicine, and
most specially conservation biology”
Schemes of Biological Classification
• 2-Superkingdom-Scheme
• 4-Kingdom-Scheme
• 5-Kingdom-Scheme
• 6-Kingdom Scheme
• 3-Domain-Scheme
2-Super Kingdom Scheme
Super
kingdom
Kingdom
Age range
Examples
Prokaryota
(Cell lacks nucleus)
Monera
3500 my - Recent
Bacteria & cyanobacteria ("blue-green algae")
Eukaryota
(Cell has a nucleus)
Protista
Late Precambrian - Recent
Single-celled microfossils (diatoms, foraminifera)
& multicellular seaweed
Eukaryota
Fungi
Silurian
Toadstools, fungi
Eukaryota
Plantae
Silurian
Plants. Multicellular
Eukaryota
Animalia
Latest
Animals.
Biological Organization under 6-Kingdom
SCHEME
•Archaebacteria or Primitive Bacteria
•Eubacteria or Modern Bacteria
•Protista or Protists
•Mycetae or Fungi
•Plantae or Plants
•Animalia or Animals
3 Domain Scheme