MODERN TAXONOMY

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MODERN TAXONOMY

• Techniques that are used today to provide
  information about an organism and its relatives.

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Today most scientists .

• recognize that organisms have changed over time.
• accept evolution as the basis for classification.

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Phylogeny

• This is a field of biology where scientists study
  the evolutionary history of living organisms.
  Phylogenists often study the fossil record and
  analyze connections to the past.

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What is a fossil ?

• A fossil is a cast or mold of an organism
  preserved in rock that formed where the organism
  died.
• A fossil could also consist of the organism
  itself in ice, amber, or in volcanic glass.
• A fossil could also consist of tracks
  (footprints), seeds, or skeleton preserved in
  deposits.

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Methods and Techniques used by todays
taxonomists.

• 1. Fossil Records Fossils provide evidence that
  show how plants and animals are related by
  preserving structures that can be studied and
  compared.

2. Homologous structures Homologous
structures are parts in different animals that
show similarities in their structure.
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Methods and Techniques used by todays
taxonomists. (contd)

• 3. Comparative embryology Taxonomists
  study the patterns of development before birth.
  Embryos of organisms believed to be closely
  related show similar patterns of development.

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Methods and Techniques used by todays
taxonomists. (contd)

• 4. Comparative biochemistry Taxonomists
  today now study the chemistry of blood, enzymes
  and other specific substances produced by animals
  and plants. Example -The hemoglobins in the blood
  cells of gorillas and humans are the same except
  for one amino acid.
  

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Methods and Techniques used by todays
taxonomists.

• 5. Comparative DNA and RNA Scientists now
  study DNA and RNA structure to see their
  similarities amoung organisms. We know that the
  DNA of humans and chimpanzees is 99 identical.
  We also know that the DNA between humans and
  other mammals (dog,horses,whales,bats,etc) is
  only about 80 identical.

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In summary some of the methods used to determine
characteristics for classification purposes are

• 1. Fossil records
• 2. Homologous structures
• 3. Comparative embryology
• 4. Comparative biochemistry
• 5. Comparative DNA / RNA (genetics)

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How are these animals compared?
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The End