Natural selection & genetic modification

• Who developed the theory of speciation and evolution by natural selection?

  Alfred Russel Wallace
• What idea did Alfred Russel Wallace have regarding individuals without survival characteristics?

  They would die out due to changes in the environment.
• With whom did Alfred Russel Wallace publish joint studies?

  Charles Darwin
• What was the significance of the publication of 'On the Origin of Species'?

  It meant Darwin received credit for the theory of evolution.
• What was one of Wallace's important works related to evolution?


  Warning coloration in animals
• What does the process of speciation begin with?

  Variation within a population due to genetic mutations.
• What happens to alleles that provide a survival advantage?

  They are selected for through natural selection.
• How can populations of a species become isolated?

  Through physical barriers such as a rock fall.
• What can happen to different alleles in a new environment?

  Different alleles may become advantageous and be selected for.
• What does increased genetic variation between two populations indicate?

  Different alleles have been selected over time.
• What signifies the formation of a new species?

  When populations can no longer breed together to produce fertile offspring.
• Who was Charles Darwin?

  A scientist and naturalist who put forward the theory of evolution.
• What supported Darwin's theory of evolution?

  Experimentation and his knowledge of geology and fossils.
• When was 'On the Origin of Species' published?

  In 1859
• What is the theory of evolution based on?

  Variation within species due to mutations in DNA.
• What does 'survival of the fittest' mean?

  Organisms with characteristics suited to the environment are more likely to survive and reproduce.
• What happens to beneficial characteristics over generations?


  They are passed on to the next generation.
• What occurs to the frequency of advantageous alleles in a population over many generations?

  It increases within the population.
• What was one reason for the controversy surrounding Darwin's ideas?

  It contradicted the idea that God was the creator of all species.
• Why was there not enough evidence for Darwin's ideas at the time?

  Few studies had been done on how organisms change over time.
• What was unknown at the time regarding inheritance and variation?

  The mechanism of inheritance and variation was not known.
• What does it mean when bacteria are labeled resistant?

  They are not killed by antibiotics that were previously effective against them.
• Why do bacteria reproduce at a fast rate?

  To quickly adapt to environmental changes.
• What can mutations during bacterial reproduction result in?

  New genes, such as the gene for antibiotic resistance.
• What creates a selection pressure in bacteria?

  Exposure to antibiotics.
• What happens to bacteria with antibiotic resistant genes?

  They survive and reproduce, passing on the advantageous gene.
• How does the presence of new resistant bacteria support Darwin's theory of natural selection?

  They have been selected by the environment for their advantageous feature of resistance.
• What is a consequence of the increase in antibiotic resistant bacteria?

  Bacterial diseases spread rapidly as people are not immune.
• What is MRSA commonly referred to as?

  A 'superbug'
• Why is MRSA called a 'superbug'?

  It is resistant to many different types of antibiotics.
• Where is MRSA commonly found?

  In hospitals.
• What does fossil evidence show about the development of organisms?

  Developments arose slowly over time.
• How can we estimate when a fossil was formed?

  Using carbon dating and related techniques.
• Who is Ardi and how old is she estimated to be?

  Ardi is the oldest known human ancestor, estimated to have lived 4.4 million years ago.
• What features does Ardi's fossilized skeleton contain?

  Humanoid features and ape-like characteristics.
• What does the presence of an 'intermediate' organism like Ardi suggest?

  Natural selection and evolution occurred gradually.
• What does the bone structure in Ardi's feet suggest?

  It is different from that of chimpanzees, indicating separate evolution.
• How old is Lucy's fossilized skeleton estimated to be?

  3.2 million years ago.
• What does Lucy's bone structure suggest about her locomotion?

  She walked in an upright, human-like position.
• What does Lucy's small, chimp-like skull indicate?

  She represents another intermediate between apes and early humans.