Evolution

• What is evolution?

  Change in the inherited characteristics of a population over time through natural selection, which may result in new species
• What is the theory of evolution by natural selection?

  The organisms that are best adapted to their environment are most likely to survive and pass on these characteristics to their offspring
• What evidence supports the theory of evolution?

  Parents pass on their characteristics to offspring in genes

  Fossil record evidence

  Evolution of antibiotic-resistance bacteria
• What are fossils?

  Remains of organisms from millions of years ago found in rocks
• How might fossils be formed?

  Parts of an organism do not decay because the conditions needed for decay are absent.

  Traces of organisms are preserved.

  Parts of an organism are replaced by minerals.
• What are the benefits of the fossil record?

  Can learn how species changed and how life developed on earth, and can track the movement of species across the world.
• What are the problems with the fossil record?

  Many early organisms were soft-bodied so left few fossils.

  Gaps in the fossil record as not all fossils have been discovered and some have been destroyed.
• What is extinction?

  No individuals of a species are still alive
• What factors contribute to the extinction of a species?

  Predators.

  Disease or pathogens.

  Competition for resources or mates.

  Catastrophic events.

  Changes in the habitat.
• What is the binomial system?

  Naming of organisms by their genus and species.
• What classification system did Carl Woese introduce?

  Three-domain system ( of Archaea, Bacteria, and Eukaryota).
• Why can bacteria evolve rapidly?

  They reproduce at a fast rate.
• How do antibiotic-resistant strains of bacteria develop?

  Mutations that allow the strain to survive and reproduce in the presence of the antibiotic.