Classification

1
Classification

• Intro to Classification systems
• From two kingdoms to five (or six)
• Binomial nomenclature and dichotomous keys

2
Introduction to Classification

• What is meant by classification?
• -To group living things based on similarities.
• Why classify living things?
• Scientific reasons.
• Medical reasons
• Taxonomy is the science of grouping and naming
  organisms.

3
Questions

1. What was the major difference(s) between how both
   Aristotle and Linnaeus classified organisms?
2. What is binomial nomenclature and who devised
   this system?
3. Explain how this binomial system works.

4
Questions Continued

• 4. Phylogeny is the study of the evolutionary
  history of organisms. Name the four lines of
  evidence used to create phylogenetic trees and
  give a brief description of what each refers to.
• 5. The modern system includes six classification
  levels. List the six levels.

5
Aristotles system

• ARISTOTLE -
• 4th century BC (384 to322 BC)Greek philosopher
  

• 2000 years ago Aristotle divided living things
  into either plants or animals .
• Animals were divided into groups based on where
  they lived land, water, or air.They were also
  grouped based on whether they were blooded or
  bloodless.
• The plants were divided into groups based on
  differences in their stems.

6
Problems with his System

• Using Aristotle's 3-group system (land, air
  water), name 2 animals that would fit each of the
  3 groups.
• Some possible Answers a. walking - cat, dog,
  human, etc.b. flying - bird, bat, butterfly,
  etc.c. swimming - fish, whale, manatee, etc.
• Do you see any possible conflicts here?
• What about a duck or an alligator?

7
Carolus Linnaeus 1707-1778

• He devised a system of grouping organisms into
  hierarchical categories based on physical
  characteristics, such as form or structure.
• For example, Linnaeus's plant taxonomy was based
  solely on the number and arrangement of the
  reproductive organs on a plant.
• Overall this proved to be a better system however
  it had some problems that resulted in many
  groupings that seemed unnatural.

8
Binomial Nomenclature

• Linnaeus devised this system
• The genus name is written first (always
  Capitalized).
• The species name is written second (never
  capitalized).
• Both words are either italicized or underlined.
• Eg.. Homo sapiens or Homo sapiens

9
Phylogeny
The four lines of evidence used to create
phylogenetic trees are

• The fossil record
• Morphology
• Embryological patterns of development
• Chromosomes and DNA

10

• The Fossil Record Anatomical similarities or
  patterns in relation to time on the evolutionary
  scale can be invaluable.
• Similarly, relationships in the Morphology (morph
  refers to form) of the creatures we see today
  allow us to categorize organisms based on these
  facts.

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• Embryological patterns of development
• The changes that an organism undergoes during its
  development can leave clues to its evolutionary
  past.

12
Chromosomes and DNA

• The amount of genetic material that two
  organisms share relates to how close they are on
  the phlogenetic tree
• Surely you have heard how humans and chimpanzees
  share 98 of the same DNA.

13

• The major classification levels,from largest
  group to smallest (several of these have
  subdivisions)
• KingdomPhylumClassOrderFamilyGenusSpecies

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Scientific classification Kingdom
Animalia Phylum Chordata Class
Actinopterygii Order Gadiformes Family
Gadidae Genus Gadus Species Gadus morhua
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Idenitifying Marine Organisms

• Some things we know by sight fish, crab
• These words are different in other languages
  poisson, fisch, pescado, pesce.
• Scientists all over the world know that Gadus
  morhua is Atlantic cod.
• There are many types of cod in the Genus Morhua
  but only one species
• Gadus morhua

16
Species

• A group of organisms that look alike and can
  interbreed under natural conditions to produce
  fertile offspring.
• When similar species are in close contact,
  interbreeding can take place for example, dolphin
  and whale to produce a wolphin. These animals
  are infertile and cant have offspring so they
  are not new species.

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Bottlenose Dolphin False Killer Whale
Wholphin or wolphinTursiops truncatus (mother)
Pseudorca cracrassidens
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Classification of Living Things

• http//www.eti.uva.nl/Database/WBD.html
• http//www.usoe.k12.ut.us/curr/science/sciber00/7t
  h/classify/sciber/history.htm
• http//www.ucmp.berkeley.edu/exhibit/phylogeny.htm
  l

http//www.howe.k12.ok.us/jimaskew/bclasfy.htm