Classification

• Who contributed to our understanding of evolution alongside Charles Darwin?

  Alfred Russel Wallace
• What was Alfred Russel Wallace particularly interested in regarding animals?

  Warning coloration in animals
• In what year did Darwin and Wallace jointly publish their findings?

  1858
• What did Darwin publish the following year after the joint publication with Wallace?

  On the Origin of Species
• What is the process called when new species form?

  • Speciation
  • Involves geographical barriers
  • Prevents interbreeding between populations
• How did Wallace contribute to the theory of evolution?

  He independently proposed the theory of evolution by natural selection
• What geographical feature did Wallace notice often separated closely related species?

  A wide river
• What are the stages of speciation as illustrated by the example of snails?

  1. Initial population can interbreed
  2. Geographical barrier (e.g., river) separates populations
  3. No interbreeding occurs
  4. Natural selection favors different alleles
  5. Mutations cannot spread between populations
  6. Over generations, populations change
  7. If they can mix again, they may no longer reproduce fertile offspring
• What happens to the populations of snails when they are separated by a geographical barrier?

  They can no longer interbreed
• Why is a geographical barrier important for speciation?

  It prevents interbreeding between separated populations
• What is the result of natural selection favoring different alleles in separated populations?

  The populations begin to change over many generations
• What is the key point for speciation to occur?

  A geographical barrier must separate a population
• What happens when the two populations of snails can mix again after being separated?

  They may no longer reproduce to make fertile offspring
• What is a common exam question related to the study of speciation?

  Describe how new species form
• What is the significance of warning coloration in animals according to Wallace's studies?

  It warns predators that the animal is poisonous
• What should you be able to describe by the end of the video on classification?

  How organisms are classified based on their characteristics
• What is the three domain classification system?

  A system used to classify organisms based on their biochemistry
• What is the purpose of using an evolutionary tree?

  To describe the relationships between organisms
• How many different species are there on Earth?

  Millions of different species
• What did scientists realize about species as more were discovered?

  They often have characteristics in common
• Who began to classify species in the 1700s?

  Carolus Linnaeus
• Into how many kingdoms did Linnaeus divide all living organisms?

  Two kingdoms: animal and plant
• What are the categories Linnaeus used to classify organisms?

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• What mnemonic can help remember the classification categories?

  King Phillip Came Over For Good Soup
• If given a classification of an organism, what might you be asked to fill in?

  A missing part of the classification
• What is the binomial system in classification?

  A naming system using genus and species
• What is the binomial name for the zebra?

  Equus quagga
• What is the binomial name for the polar bear?

  Ursus maritimus
• What is the key fact about Linnaeus's classification system?

  It is based on observable characteristics
• What major advances in biology have occurred since Linnaeus's time?

  Use of microscopes and analysis of biochemistry
• Who developed the three domain system?

  Carl Woese
• What are the three domains in the three domain system?

  Archaea, Bacteria, and Eukaryota
• What are characteristics of Archaea?

  Often found in extreme conditions such as hot springs
• What do true bacteria include?

  Bacteria that live in the human digestive system
• What does the domain Eukaryota include?

  Animals, plants, fungi, and protists
• How do scientists create evolutionary trees?

  By using classification data and DNA analysis
• What is a challenge when using fossils for evolutionary trees?

  The fossil records of many species are incomplete
• What does an evolutionary tree show about species one, two, and three?

  Species one and two are closely related, while species three is more distantly related
• What do species one, two, and three share according to the evolutionary tree?

  A common ancestor
• Where can you find plenty of questions on classification and evolutionary trees?

  In the revision workbook