Evidence for Evolution

• What is comparative genomics?

  It is the comparison of human genomes to genomes of other organisms.
• How does comparative genomics support evolutionary relationships?

  By checking for genome sequence alignment and DNA sequences that share a common ancestry.
• What genomic features are compared in comparative genomics?

  DNA sequence, genes, and gene order.
• What does a greater degree of similarity in genomic sequences indicate?

  It indicates a closer evolutionary relationship between two species.
• What type of genetic information do endogenous retroviruses store?

  They store their genetic information in RNA.
• What happens during reverse transcription in retroviruses?

  The retrovirus copies its genome into DNA when entering a cell.
• What occurs after the DNA from a retrovirus is inserted into a host cell?

  The DNA becomes inserted into one of the host cell’s chromosomes.
• When does a retrovirus become endogenous?

  When it inserts into a gamete cell.
• What do offspring inherit from endogenous retroviruses?

  They inherit copies of the ERV.
• What do comparisons of junk DNA reveal about evolutionary relationships?

  More closely related species have more junk DNA sequences in common.
• Where is mitochondrial DNA found?

  It is found within the mitochondria in small, circular plasmid form.
• How is mitochondrial DNA inherited?

  It is inherited from the mother via the mitochondria in her ova.
• What is the significance of mutations in mitochondrial DNA?


  Mutations occur more readily in mtDNA and can be correlated with time elapsed.
• What does greater diversity in mtDNA indicate?

  It indicates that the species are less closely related.
• How do differences in DNA sequences affect protein sequences?

  Differences in DNA sequences give rise to different amino acid sequencing.
• What is the significance of the Cytochrome C protein?

  It contains 104 amino acids that need to be aligned to determine evolutionary relationships.
• What does greater similarity between two molecules indicate?

  It indicates that they have more recently evolved from a common ancestor.
• What is bioinformatics?


  It combines computer science, statistics, mathematics, and engineering to analyze and compare DNA.
• How does bioinformatics support evolutionary relationships?

  By comparing entire genomes and analyzing similarities in specific genes and nucleotides.
• What are the key concepts of comparative anatomy?

  • Homologous structures: similar anatomical structures indicating a common ancestor.
  • Vestigial structures: structures that are present but not functional, indicating a common ancestor.
  • More similar structures are present for longer in embryonic stages, indicating closer relationships on phylogenetic trees.
• What do homologous structures indicate?

  They indicate a common ancestor.
• How do vestigial structures support evolutionary theory?

  They show structures that have a benefit in some species but are present but not functional in others, indicating a common ancestor.
• What do phylogenetic trees represent?


  They represent evolutionary relationships between organisms.
• What do more recent common ancestors on a phylogenetic tree indicate?


  They indicate more closely related species.
• What do less recent common ancestors on a phylogenetic tree indicate?

  They indicate less closely related species.
• What is a fossil?

  A fossil is any preserved trace left by an organism that lived long ago.
• What is the importance of fossils in providing evidence for evolution?

  Fossils show common ancestry, provide evidence of past organisms, extinct organisms, and transitional organisms between species.
• What are the stages of fossil formation?

  1. Animal dies and is buried in sediment.
  2. Sediment layers accumulate and replace bone with minerals.
  3. Tectonic plate movement pushes fossil closer to the surface.
  4. Erosion exposes the remains.
• What conditions are needed for fossilization?

  Alkaline soil with low oxygen levels, hard bones/teeth, and protection from decay by microorganisms and sediment.
• What increases the chance of fossilization?

  Having hard body parts, alkaline soils, and soils with no oxygen.
• What are some limitations of the fossil record?


  Fossils can be buried too deep, destroyed by human activity, weathering, geological processes, or may not be discovered.
• What is absolute dating in fossils?

  It determines the actual age of the specimen.
• What is potassium-argon dating?

  It is based on the decay of radioactive potassium-40 into calcium and argon.
• What is the half-life of potassium-40?

  The half-life is approximately 1.25-1.3 billion years.
• What is carbon-14 dating?

  It is based on the decay of carbon-14 to nitrogen and compares the ratio of C-14 to C-12 to determine age.
• What is the half-life of carbon-14?

  The half-life is 5730 years.
• What is relative dating in fossils?


  It determines whether a sample is older or younger than another.
• What is stratigraphy?


  It is the study of rock layers on site or from photographs.
• What does the principle of superposition state?

  Layers of rocks on top are younger than the rocks beneath.
• What is correlation of rock strata?

  It is matching layers of rock from different areas by examining the rock itself or the fossils within it.