Taxonomy is the science of naming and classifying organisms. It involves grouping organisms into a hierarchical classification system based on similarities. The goal of taxonomy is to organize the diversity of life into a comprehensive classification scheme. Some key aspects of taxonomy include binomial nomenclature, which assigns each species a unique two-part scientific name, and dichotomous keys, which allow identification of unknown organisms through a series of choices. Modern taxonomy also incorporates evolutionary relationships revealed by phylogenetic analysis of genetic, morphological, and fossil data.

1. Taxonomy
The science of naming organisms.

3. •Phylogeny
•Systematics
Hypothesis
•Cladistics
•Derived
character
•Cladogram
•Dichotomous
Key
•Classification
•Taxonomy
•Aristotle
•Linnaeus
•Kingdom
•Phylum
•Class
•Order
•Family
•Genus
•Species
•Common name
•Scientific
name
•Binomial
nomenclature

4. Aristotle
• Plant or animal?
• If an animal, does it
– Fly
– Swim
– Crawl
• Simple classifications
• Used common names

5. Carolus Linnaeus
• Described organisms with two word
names, instead of polynomials
• Developed binomial nomenclature
• First word = genus name
• Second word = species name

6. • Taxonomy is the science of grouping
and naming organisms.
• Classification the grouping of
information or objects based on
similarities.

7. Why use a dead
language?
•We only know about a fraction of the
organisms that exist or have existed on
Earth.
•Taxonomists give a unique scientific name to
each species they know about whether it’s
alive
today or extinct.
• The scientific name comes from one of two
“dead” languages – Latin or ancient Greek.

8. Devil Cat

9. Ghost Cat

10. Mountain Lion

11. Screaming Cat

12. Puma

13. Florida Panther

14. Cougar

15. •There are at least 50 common names for
the animal shown on the previous 7 slides.
•Common names vary according to region.
•Soooo……why use a scientific name?

16.
•a two name system for writing scientific names.
•The genus name is written first (always Capitalized).
•The species name is written second (never
capitalized).
•Both words are
italicized if typed or underlined if hand written.
Example: Felis concolor or F. concolor
Which is the genus? The species?
Binomial Nomenclature

17. "Formal" scientific names should have a third
part, the authority.
The authority is not italicized or
underlined.
The authority is written as an abbreviation of
the last name of the person responsible for
naming the organism. Since Carolus Linnaeus
was the first person to name many plants,
the L. for Linnaeus is very common in plant
scientific names.
An example is Quercus alba L.

18. Phylogeny, the evolutionary history of an
organism, is the cornerstone of a branch
of biology called systematic taxonomy.
Systematics, as systematic taxonomy is
commonly called, is the study of the
evolution of biological diversity.

19. A phylogenetic tree is a family tree
that shows a hypothesis about the
evolutionary relationships thought
to exist among groups of organisms.
It does not show the actual
evolutionary history of organisms.
Why a hypothesis?

21. Phylogenetic trees are usually based
on a combination of these lines of
evidence:
Fossil record
Morphology
Embryological patterns of
development
Chromosomes and DNA

22. Fossil

23. Morphology

24. Homologous
Structures

25. Adaptive Radiation -
modifies
homologous
structures
Modifies homologous structures

27. These animals have evolved similar adaptations
for obtaining food because they occupy similar
niches. What can you infer about their
phylogeny from their geographic locations?
Convergent Evolution

28. Analogous Structures -
•Traits that are morphologically and
functionally similar even though there
is no common ancestor.
Convergent evolution leads to……….

32. Embryology

33. Cladistics - is a relatively
new system of phylogenetics
classification that uses
shared derived characters to
establish evolutionary
relationships. A derived
character is a feature that
apparently evolved only within
the group under
consideration.

34. DNA

35. There are three basic
assumptions in cladistics:
1.Organisms within a group are
descended from a common
ancestor.
2.There is a bifurcating pattern
of cladogenesis.
3.Change in characteristics
occurs in lineages over time.

36. A phylogenetic tree based on a
cladistic analysis is called a
cladogram.
What derived character is shared by
all the animals on the cladogram on
the next slide?

38. The acacia and its
ants are an example
of coevolution. Each
influences the others
evolution.
Can you think of any
other examples of
coevolution?

39. Punctuated Equilibrium
“instead of a slow, continuous movement,
evolution tends to be characterized by long
periods of virtual standstill ("equilibrium"),
"punctuated" by episodes of very fast
development of new forms”
The "punctuated equilibrium" theory of
Niles Eldredge and Stephen Jay Gould was
proposed as a criticism of the traditional
Darwinian theory of evolution…what is it
called?

40. • A key is a device for easily and quickly
identifying
an unknown organism.
• The dichotomous key is the most widely
used type in biological sciences.
• The user is presented with a sequence of
choices between two statements, couplets,
based on characteristics of the organism. By
always making the correct choice, the name
of the organism will be revealed.
The Dichotomous Key

42. 1.
A. one pair of wings
B. Two pairs of wings

43. The Three Domains
• Domain Archaea
– Includes newly discovered cell types
– Contains 1 kingdom – the Archaebacteria
•Domain Bacteria
– Includes other members of old kingdom
Monera
– Has 1 kingdom – the Eubacteria
•Domain Eukarya
– Includes all kingdoms composed of organisms made
up of eukaryotic cells
– Protista
– Fungi
– Animalia
– Plantae

44. The major classification levels,
from most general to most specific
(several of these have subdivisions)
A group at any level is a taxon.

45. All organisms classified in a
hierarchy
• Kingdom (broadest)
• Phylum
• Class
• Order
• Family
• Genus
• Species (most specific)

46. Kingdoms are divided into groups called phyla
Phyla are subdivided into classes
Classes are subdivided into orders
Orders are subdivided into families
Families are divided into genera
Genera contain closely related species
Species is unique
Categories within Kingdoms

48. The 6 kingdoms
• Prokaryotes (Used to be 1 kingdom,
Monera)
– Archaebacteria
– Eubacteria
• Eukaryotes
– Fungi
– Protista
– Animal
– Plantae

49. Overview of the 6 kingdoms
• Archaebacteria
– Unicellular
– Live in extreme environments
– Prokaryotic
• Eubacteria
– Unicellular
– Prokaryotic
– “Common bacteria”

50. Overview of the 6 kingdoms
• Protista
– Eukaryotic
– Unicellular or colonial
– Lots of different life styles
• Fungi
– Cell walls made of chitin
– Eukaryotic
– Multicellular
– External heterotrophs

51. Overview of the 6 kingdoms
• Plantae
– Eukaryotic & Multicellular
– Cell walls made of cellulose
– Autotrophic
• Animalia
– Eukaryotic & Multicellular
– No cell walls
– Internal heterotrophs

52. Why is taxonomy useful?
• Helps prevent confusion among
scientists
• Helps to show how organisms are
related
• Can be used to reconstruct
phylogenies – evolutionary histories –
of an organism or group