Tuesday, April 29

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Tuesday, April 29

• Do Now- hand in worksheet 15-4
• 1. Notes chapter 15
• 2. Note cards
• 3. Review note cards
• HW- STUDY for Evolution test tomorrow

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Chapter 15

• Fossil Dating and Classification

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Dating Fossils

• Radiometric Dating- uses radioactive material to
  determine the date of a fossil
• Method used most often to date fossils

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Half-Life

• Half-life- the number of years it takes for half
  of the radioactive material to break down
• Examples Uranium-238 has a half-life of 4.5
  billion years, Carbon-14 has a half-life of 5700
  years.

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Continental Drift

• The continents are slowly drifting relative to
  each other on plates.
• Look at the diagram on page 339 and notice the
  movement of the continents throughout time

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Classification

• Chapter 15 Section 4

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Why do scientists classify?

• Scientists classify to organize living things
  into groups so that its easier to study.
• Example Plants, Animals,

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• Classification- is the process of grouping things
  together by their similarities.
• Taxonomy- the study of how living things are
  classified.

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Early Classification Systems

• Aristotles Method - used observations to
  classify and create groups of organisms which had
  similar characteristics.
• Examples
• Swimming
• Flying
• Walk or Crawl
  
  
  
  
  
  
  
  
  
  

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The Classification Systems of Linnaeus

• Binomial nomenclature - each organism is given a
  two-part name.
• Example Humans are Homo sapiens.

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Binomial Nomenclature

• Genus - a group that has similar,closely
  related organisms.
• Ex. Felis has sharp teeth, retractable claws
  (house capumas).
• Species - similar organisms, which can mate
  and reproduce fertile offspring.
• ex. Felis domesticus of the house (house
  cat)

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Levels of Classification
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Seven Levels of Classification

• Kingdom - Animalia
• Phylum - Chordata
• Class - Aves
• Order - Strigiformes
• Family - Strigidae
• Genus - Bubo
• Species - virginianus (great horned owl)

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Classification Today
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What information do scientists use to obtain
clues about evolutionary history?

• a. share common ancestor
• b. study fossils
• c. compare body structures
• d. compare early development

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Using the classification system

• Taxonomic key - a series of paired statements
  which describe the physical characteristics of
  different organisms.