This document discusses the concepts and history of systematic zoology and taxonomy. It defines taxonomy as the classification of living things and systematics as the scientific study of diversity and relationships among organisms. It outlines the contributions of taxonomy in fields like epidemiology and wildlife management. The document then discusses the scope of taxonomy, problems in taxonomy, and provides a history of taxonomy from Aristotle to modern molecular systematics approaches.

1. SYSTEMATIC ZOOLOGY
Main Concepts & Definition By Yousaf Rafique

2. Science of Systematic Zoology
Taxonomy:
Term was used by de Candolle in 1813.
Taxa is a Greek word which means naming or arrangement while nomos means law.
It can be defined as,
“The theory of practice of classification of living things”.
Systematics:
First used by Swedish scientist, C. Linnaeus in 1735 in his book “ Systema Naturae”.
Dictionary definition is, “ Study of diversity of living things or classification system”.
Modern definition is , “The scientific study of kinds and diversity of living things and any
Relationship among them”.

3. CONTRIBUTION OF SYSTEMATIC
ZOOLOGY AND TAXONOMY
Epidemiology
Study of disease and their outbreaks.
Wild life management
Flora and fauna are discussed.
They balance each other.
Environmental
problems
Control of environmental problems by
degrading organism which degrade
waste products.

4. SCOPE OF TAXONOMY
1. Works on existing diversity on earth and the only sciences they does do.
2. Provide much of the information about phylogeny of life.
3. Provide information required for all biology branches especially for biogeography.
4. Makes important conceptual contribution in a population thinking.

5. PROBLEMS
1. Taxonomist and systematist face various problems.
2. Species form complex population which cannot be categorized as whole.
3. Some species have different life cycles like egg, larvae ang adult stages which are sometime
considered as different species.
4. Problem lies in arranging species at higher categories.

6. HISTORY OF TAXONOMY
• Taxonomy is old as human civilization.
• In early life, classification of plants and animal was done on the bases of similarities
and dissimilarities, harmful and harmless or edible or non-edible.
• With the passage of time, classification created problems throughout the world with
the evolution of human civilization and discovery of more and more species.
• Later on, some great scholars and taxonomists worked to finalize & streamline the
classification of plants and animals, some of which are discussed in next slides.

7. ARISTOTLE(384-322)
• He was the father of biology and classified the animals and plants on the bases of their
morphology, anatomy, habits and habitats and embryology, which was quite different from
the classification done before him by teachers.
• He divided the animals on the bases of their morphology into following groups
1. Blooded vs bloodless
2. Wings vs wingless
3. Two footed vs four footed
4. Hairy vs hairless
5. Aquatic vs terrestrial
6. Oviparous vs viviparous or ovoviviparous

8. • He adopted the anatomy for classification so for the 1st time, he dissected and studied
the internal anatomy.
• In dissection, he discovered that Dolphin is mammal not fish.
• He is also known as the father of family tree.
• He arranged the animals in a ladder like structure in specific order and some blocks
were left for organisms which were not described yet.
Later on history of taxonomy was divided into pre-Linnaean, Linnaean and
post-Linnaean periods.

9. PRE-LINNAEAN PERIOD (12TH -17TH CENTURY)
• Pre-Linnaean period started very early in 12th century till 17th century and plants & animals were categorized in
different positions and ranks by naturalist and taxonomists.
• John Ray(1627-1705) classified the plants and published details of over 18,000 plant species.
• By the invention of microscope(1665), microorganisms were discovered and animals & plants were classified into
different class.
• Lamarck(1744-1829) classified the animals into vertebrates and invertebrates.
• In the late 17th century, embryologists divided animals into protostomes and deuterostomes.

10. LINNAEAN PERIOD(1707-1778)
• Carl. Linnaeus was Swedish naturalist and is known as the modern father of
taxonomy.
• For the time, he proposed the system of classification of living things in which the
positions were ranked as Kingdoms, Phylum, Class and order etc.
• He gave the binomial numen cloture system for naming the living things which
removed the difficulties from classification.
• In his system, name consists of two parts, one is species while other is genus name.
• He published his work in his book, “Systema Naturae” in 1735 paved the way for
classification.
• He classified 3500 species of plants and 2000 species of animals in two different
categories.

11. POST-LINNAEAN PERIOD(1800 TO TILL DATE)
• Started in 19th century and many biologists, taxonomists, embryologists and molecular systematists worked to
classify the animals and plants on the bases of external and internal anatomy, morphology, biology, genetics and
developmental stages.
• Lamarck classified the animals on the bases of vertebral column and use and disuse of organs.
• George Cuvier in 1809 rejected the Lamarck’s classification and classified animals on the bases of adaptations into
different groups. He is also known as the father of paleontology.
• Darwin(1809-1885) defined the species as, “The group of individuals which share common ancestor”.
• In 1876 and 1902, chromosome and Mendelian work was discovered, so molecular systematists defined as, “Those
individuals which have a common sequence of molecule in DNA”.
• With the passage of time, Mayr in 1969 defined the species as, “Those individuals which can interbreed freely and
produce fertile offspring”. But sterile individuals produce difficulties in the species concept.
• In 1934-36 Haeckel classified the animals on the bases of embryological stages.
• Later on morphology species concept originated which defined species as, “Those individuals which have the
common morphology i.e. similar characters in a particular area.

12. • It was a great problem for taxonomists and systematists to classify the animals as described by the Linnaeus so they
included some categories in Linnaean classification such as subphylum, subclass, superclass, superclass etc.
• Species was considered as a fundamental unit for system of classification.
Population:
A number of organisms of the same species that live in a particular geographical area at the same time with the ability
of freely interbreeding.
Community:
The interacting group of various species in a common location.

13. CONCEPTS & TERMS USED IN
TAXONOMY
• Classification:
The ordering of population or group of population at all level by deductive procedure.
• Identification:
The ordering of individuals by deductive procedure as previously established classes(taxa's).
• Taxon:
The group of real organisms recognized as formal unit at any level of classification. Morphological similar organisms
in population.
• Differences:
The features on the bases of which species can be differentiate from other species.
• Accident:
The characters which may be present in some species but not in all species.
• Property:
The characters which present in all the members of a species but not serve as the base for classification.