dasd

1. A. Taxonomy Defined
1. Grouping of organisms - the science of
classifying living organisms based on shared
features
2. Principles of classification – the practice
or principles of classification
3. Study of classification – the study of the
rules and practice of classifying living
organisms

2. QUESTION:
Would you also consider that
taxonomy deals with
IDENTIFICATION of living
organisms? Why or why not?

3. Taxonomy involves:
1. Classification – ranking of groups of
organisms in some hierarchical relationship
- based on their similarities in their
characteristics (genetic relationship, internal
and external anatomy, physiology or
evolutionary history)
2. Identification – separation of one group
from other groups according to their unique
characteristics

4.  Identifying organisms based on their
morphology, anatomy, physiology, cytology,
biochemistry and geographic distribution
WHAT ARE THE ROLES of TAXONOMISTS
and SYSTEMATICISTS?
To classify, identify and make a census
of the unique characteristics of each
species.

5.  To reconstruct the evolutionary history of the
present classified species based on
morphology, anatomy, chemical
composition, geographic
distribution, breeding behavior, and
chromosome number
 To determine which traits are advanced
(derived in time from primitive traits) or
primitive

6.  To discover all species of animals.
 To reconstruct their evolutionary
relationships.
 To classify animals according to their
evoutionary relationships.

7.  Unexplored areas, only an estimation could
be done
 Continuous evolution process (diversification)
 Continuous extinction
 How about in local settings?

8.  300 BC
Aristotle – used dichotomies or polar opposites
Ex. Animals with blood and without blood
(vertebrates and invertebrates)
- wrote extensively on both plants
and animals but his writings on plants were
lost
Theophrastus – Aristotle’s pupil and applied
his approach to the study of plants in his
work “Inquiry into Plants”

9. Theophrastus – subdivided plants based on
shape, and into broad categories as
trees, shrubs, and herbs
Dioscorides – developed a more practical
approach
- Ex. Medicinal herbs were separated
from those used in making perfumes

10. Polynomial System
-translation of the common names of
organisms into Latin
-each species was described in Latin by a
sentence limited to 12 words that begins with
the genus name
-Ex. Spiderwort -Tradescantia ephemerum
phalangoides tripetalum non repens
virginianum gramineum
Common name: Tradescantia virginiana

11. Translation: The annual, upright Tradescantia
from Virginia which has a grasslike habit, 3
petals, and stamens with hairs like spider
legs, common name Tradescantia of Virginia
But the polynomial system was simplified into a
two-word or BINOMIAL naming system in the
mid-16th century to mid-17th century by a
group of naturalists known as herbalists.

12. Andrea Cesalpino – first scientist to classify
plants primarily according to structural
characteristics, such as their fruits and seeds
Caspar Bauhin – adapted Cesalpino’s method;
catalogued an extensive list of plants

13. Animal Classification Advanced
Pierre Belon
– extensively studied and catalogued birds
-first to use adaptation to habitat to divide
birds as AQUATIC, WADING, PERCHING, and
LAND BIRDS and BIRDS of PREY

14. John Ray – used key characteristics such as the
shape and size of the birds’ beak to classify
birds
MID 1700s
Carolus Linnaeus
Binomial system of nomenclature – similar
organisms are grouped into a genus, and
each organism is given a two-word Latin
name

15. Carolus Linnaeus
Binomial nomenclature
first name – genus name
second name – adjective describing the
organism, its geographic location or the
person who discovered it
Ex. domestic dog
Canis familiaris

16. Canis – genus name for the group of animals
that includes dogs, wolves, coyotes, and
jackals
familiaris – acts as a descriptor to further
differentiate the domestic dog from its wild
cousins

17. Carolus Linnaeus – also designed the
HIERARCHICAL classification scheme
 Kingdom
 Phylum
 Class
 Order
 Family
 Genus
 Species

18.  Development and use of microscopes
presented new classification problems which
still relied on a 2-kingdom classification
system (Plantae and Animalia

19.  Charles Darwin
-published “On the Origin of Species” in 1859
-argued that classification system should
reflect the history of life; species should be
related based on their shared ancestry
-emphasis on taxonomy shifted to:
a. A search for characters which reflected
genetic (evolutionary) relationships; and
b. The construction of a phylogenetic
classification scheme

20.  Phylogenetic – based on genetic, evolutionary
relationships
- which traits are primitive or
advanced

21. Ernst Haeckel
-proposed placing the unicellular forms in
kingdom Protista; placed bacteria within this
kingdom
1930s
Edouard Chatton – distinguished prokaryotes
and eukaryotes

22. Herbert Copeland
-prokaryotes in the 4th kingdom, Monera
1950s
Robert Whittaker
-proposed adding a 5th kingdom, Fungi
1970s
Advances in molecular systematics

23. Polymerase chain reaction – permits easy
analysis and comparison of DNA structures
Carl Woese – determined that archaebacteria
were found to have unique molecular
structures and physiological characteristics
from bacteria
-proposed a 6-kingdom
classification system

24. Other scientists propose an 8-kingdom system

25.  Modern animal taxonomy was established
using evolutionary systematics and recent
cladistic revisions.
 PhyloCode
-new taxonomic system
-being developed as an alternative to
Linnaean taxonomy
-replaces Linnaean ranks with codes that
denote nested hierarchy of monophyletic
groups converged by cladograms

26.  The terms
“primitive”, “advanced”, “specialized”, and
“generalized” are used for specific
characteristics and not for groups as a whole.