This document discusses the five main types of taxonomic characters used to classify organisms: morphological, physiological, ecological, ethological, and geographical. It provides examples of characters under each type, such as external features, anatomy, genetics, metabolism, behavior, habitat preferences, and geographic distributions. The document emphasizes that taxonomic characters should be evaluated together to properly identify and relate different species.
2. THE KINDS OF TAXONOMICAL CHARACTERS
FALL UNDER FIVE HEADINGS...
MORPHOLOGICAL CHARACTERS
PHYSIOLOGICAL CHARACTERS
ECOLOGICAL CHARACTERS
ETHOLOGICAL CHARACTERS
GEOGRAPHICAL CHARACTERS
3. EXTERNAL FEATURES PROVIDE PRIMARY AND
EVIDENT SOURCE FOR IDENTIFYING THE
TAXONOMIC CHARACTERS
THEY RANGE FROM SUPERFICIAL FEATURES AS
PLUMAGE AND PELAGE CHARACTERS OF
BIRDS AND MAMMALS,SCALES IN REPTILES
AND FISH,SCLERITES AND SUTURES OF
ARTHROPOD BODY
ANIMAL WITH EXTERNAL
SKELETON(ARTHROPOD &MOLLUSCS)
4. IN GENERAL THE GENITALIC DIFFERENCE MUST BE
EVALUATED JUST LIKE OTHER
CHARACTERS;BECAUSE GENITALIC STRUCTURES
APPEAR TO BE AMONG THE FIRST TO CHANGE IN
THE COURSE OF SPECIATION.
GENITALIC FEATURES HAVE BEEN FOUND TO
VARY IN THE SAME MANNER AS OTHER
CHARACTERS(JORDAN,1905)
GENITALIC DIFFERENCES WILL LEAD TO RI
(reproductive isolation-leon dufour)
DUFOUR PROPOSED A LOCK AND KEY
HYPOTHESIS –STRUCTURAL DIFFERENCE IN
GENITALIA PREVENT SPECIES FROM HYBRIDISING
5.
6. ANATOMY ALSO PROVIDE ABUDANT SOURCE
FOR TAXONOMIC CHARACTERS IN
PRACTICALLY ALL GROUPOF HIGHER ANIMALS
Eg: INTERNAL SKELETON(The skull) ARE
ROUTINELY PRESERVED FOR IDENTIFICATION
7. IT OFFER TAXONOMIC CHARACTERS OF GREAT
PHYLOGENETIC SIGNIFICANCE...
CLEAVAGE PATTERN
BLASTULATION
GASTRULATION
Eg:The total holoblastic cleavage of springtail
emphazize a wide gap which seperate this group
from apterygota and pterygota
8. IT IS ALSO A DETERMINATION FACTOR FOR
TAXONOMIST TO CHARACTERISE AN
ORGANISM,THE SIMPLEST CYTOLOGICAL
CHARACTER IS CHROMOSOMAL NUMBER
CHROMOSOMAL NUMBER HAVE BEEN
RECORDED FOR THOUSANDS OF ANIMALS
,SUCH STUDIES HAVE USED AS A EVIDENCE
OF PHYLOGENETIC RELATION SHIP
CHROMOSOME MORPHOLOGY
(CHROMOSOMAL VARIATION)
Eg:DROSOPHILA
9. A.METABOLIC FACTORS
1.ENZYMATIC ACTIVITY(ANABOLIC AND CATABOLIC
REACTIONS)
2.CELL CHEMISTRY(GRAM –VE &GRAM +VE )
METABOLIC REQUIREMENTS ARE OF GREAT
IMPORTANCE ;WHETHER A BACTERIA IS AEROBIC OR
ANAEROBIC,AND HOW THEIR CULTURAL GROWTH
PATTERN AND COLORATION IN MEDIA
IT IS HELPFUL IN THE SEPERATION OF CLOSELY
RELATED SPECIES
10. SEROLOGY IS CONCERNED WITH THE NATURE AND
INTERACTION OF ANTIGENS AND ANTIBODIES
ANTIGENS ARE THE SUBSTANCES CAPABLE FOR
INDUCING THE FORMATION OF ANTIBODIES WHEN
INTRODUCED IN TOTHE BLOOD STREAM OF ANIMALS
ANTIBODIES PRODUCED IN RESPONSE TO THE
INTRODUCTION OF FOREIGN ANTIGEN
BOVDEN(1943) HE LISTED THE BASIC PREMISES OF
SEROLOGY AS FOLLOWS:
1. THE ANTIGENIC COMPOSITION IS AN IMPORTANT PART
OF THEIR ESSENTIAL NATURES MAY BE CONSIDERED IN
NATURAL SYSTEM OF CLASSIFICATION
2.PROTEIN ANTIGENS ARE CONSERVATIVE HEREDITARY
TRAIT
3.GOOD PRECIPITIN TECHNIQUE ARE WELL ADAPTED TO
REVEAL THE RELATIVE DEGREE OF BIOCHEMICAL
SIMILARITY OF PRIOTEIN ANTIGENS
11. THIS WAS AN ANOTHER PHYSIOLOGICAL
CHARACTER WHICH HAS PROVED USEFUL IN
TAXONOMY INVOLVE BODY SECRETIONS
WHICH FORM CONSISTENT PATTERNS
Eg:THE WAXY SECRETIONS OF SCALE
INSECTAND MEALY BUG
FROM THIS WAX PATTERNS WE CAN
UNDERSTAND
MORPHOLOGY
THE NUMBERS
SIZE
ARRANGEMENT OF WAX GLANDS
12. EARLY TAXONOMIST KNEW THAT THERE IS
MUCH STERILITY IN BETWEEN MEMBERS OF
DIFFERENT SPECIES SO ITS IS CONSIDERED AS
A CRITERIA FOR IDENTIFYING TAXONOMIC
FEATUTRES
Eg: 1. IN SOME CASES DISTINCT SPECIES MAY
COMPLETELY INTERFERTILE
2.THERE MAY BE A CONSIDERABLE AMOUNT
OF STERILITY EVEN BETWEEN SUBSPECIES OF A
SINGLE SPECIES
13. A.HABITAT
EACH SPECIES HAVE ITS OWN RANGE OF TOLERANCE
OF HABITAT
NO TWO SPECIES WITH IDENTICAL ECOLOGICAL
REQUIREMENT CAN COEXIST IN THE SAME
PLACE(GAUSE’S LAW)
EACH GENERA OCCUPIES A SEPERATE ADAPTIVE ZONE
(SIMPSON)
Eg: GALAPAGOSE FINCHES
• HOST discrimination
• THE METHOD OFUSING DIFFERENCE IN PARASITE OR
COMMENSAL TO DISTINGUISH BETWEEN EXCEEDINGLY
SIMILAR SIBLING SPECIES IS VERY USEFUL
14. FOOD IS A IMPORTANT TAXONOMIC
CHARACTERS IN MONOPHAGOUS OR
PARASITIC ORGANISM
c.seasonal variation
• SEASONAL VARIATION ARE ALSO A KIND OF
TAXONOMIC FEATURES.FROM THIS WE CAN ALSO
IDENTIFY THE ORGANISMS
• Eg: stick insect,butterfly,polar bear
15. Eg; CASE OF BARK BEETLE
Eg: TAPE WORM (Hymnolepis nana) in man &
H.fraterna in rodents
Eg: ASCAIS in humans and pig are different
16. IT IS THE REACTION OF THE HOST TOWARDS
A SPECIFIC PARASITE.IT HAS BEEN USED FOR
TAXONOMIC PURPOSES
Eg: GALLS PRODUCED IN RESPONSE TO
ATTACK BY VARIOUS GALL WASPS
(CYNIPIDIAE) GALL FILES
17. A.COURTSHIP AND OTHER ISOLATING
MECHANISMS
DIFFERENCE IN MATING HABITS ARE
ESPECIALLY IMPORTANT BEHAVIOR
CHARACTERS,SINCE THEY ARE MORE LIKELY
TO RESULT IN REPRODUCTIVE ISOLATION
AND CONSEQUENT SPECIATION
Eg : slugs
18. 1.THE NATURE OF WEBBING CONSTRUCTED
BY VARIOUS SPIDERS
2.THE USE OF EXTRANEOUS MATERIAL IN
THE CONSTRUCTION OF NEST OR LARVAL
OR PUPAL CASES
3.SOME BEHAVIOURAL PATTERN ARE MORE
CONSERVATIVE
.DRINKING HABIT OF PIGEON AND SAND
GROUSE
USE OF MUD IN NEST BUILDING
19. A. GENERAL BIOGEOGRAPHICAL
PATTERN
BIOGEOGRAPHERS HAVE DIVIDED THE WORLD
IN TO REALMS,REGIONS,PROVINCES,SUB
PROVINCES Etc.. BASED UPON GENERALISED
COMPARISON OF FAUNA AND FLORA
A TAXONOMIST SHOULD HAVE AN
UNDERSTANDING OF THE GEOLOGICAL
HISTORY OF THE REGIONS IN WHICH SUCH AS
A BIOTAS CENTER,AND THE KNOWLEDGE OF
THE PAST RELATIONSHIPS OF THE FAUNA
AND FLORA
20. SYMPATRIC--ONE PARTICULAR SPECIES IS
FORMED IN A SAME
POPULATION(REPRODUCTIVE ISOLATION--
EVOLUTIONARY PROCESS---NEW SPECIES)
ALLOPATRIC--ONE PARTICULAR SPECIES IS
EVOVED DUE TO GEOGRAPHICAL
SEPERATION(THIS DISTRIBUTIONAL PATTERN
IN CLOSSELY RELATED FORMS IS NOW
GENERALLY CONSIDEREA TO BE INDICATIVE
OF A POLYTYPIC SPECIES CONSISTING OF
SEVERAL SUBSPECIES)
21. THEY HAVE DIAGONOSTIC ASPECTS AS
INDICATORS OF DIFFERENCE
THEY FUNCTION AS INDICATORS OF
RELATION SHIP
KEY CHARACTERS –EASILY
PRODUCED,VARIABILITY,REPRESENTING
MATERIAL
HELP IN CLASSIFICATION OF ORGANISMS