L22 - Phylogenies

• What does "biological diversity" refer to?

  Variability among living organisms
• What are the sources of biological diversity?

  Terrestrial, marine, and aquatic ecosystems
• What are the levels of diversity in organisms?

  • Morphological
  • Functional
  • Biochemical
  • Genetic (molecular)
  • Ecological
  • Taxonomical
  • Geographical
  • Embryo development
  • Behavioural
  • Life cycles
• How can morphological diversity be useful?

  It helps identify relationships among organisms
• What is a potential issue with morphological diversity?

  Similar appearances can hide genetic differences
• What is genetic diversity?

  Variability in genetic characteristics among organisms
• What does the c-value represent?

  Genome size of an organism
• What is the c-value paradox?

  No correlation between genome size and complexity
• What are the sources of genetic diversity?

  • Mutations (point mutations, insertions, deletions)
  • Chromosomal changes (translocations, loss, duplication)
  • Recombination

  
• What is a genome?

  Full manual for making an organism

  
• What is a transcriptome?

  Active genes in particular cells or tissues
• What is an epigenome?

  Extra layer of information affecting gene reading
• Why is genetic diversity important?

  It allows populations to evolve with environmental changes
• What can lead to loss of genetic diversity?

  Reduction in population size
• What are the mechanisms of genetic diversity loss?

  • Natural selection
  • Genetic drift
  • Inbreeding depression
• What is phylogenetics?

  Study of evolutionary relationships between entities

  
• What are the components of a phylogenetic tree?

  • Tip
  • Branch
  • Root
  • Node
  • Confidence value
• What is a clade?

  A group of all descendants from a common ancestor
• Why is the concept of "no such thing as a fish" important?

  It highlights paraphyletic groups in phylogenetics
• How do shared characteristics relate to phylogenies?

  Phylogenies are based on shared characteristics
• What are homologies and homoplasies?

  • Homologies: Similarities from common ancestry
  • Homoplasies: Similarities not from common ancestry
• What is convergent evolution?

  Different organisms evolve similar traits independently
• What are the pros and cons of molecular phylogenies?

  Pros:

  • Information rich
  • More reliable

  
  

  Cons:

  • Expensive
  • Requires expertise and time
• How do molecular phylogenies compare to morphological ones?

  Molecular phylogenies often align better with biogeography

  
• What is the significance of resolving phylogenies?

  It enhances our understanding of evolutionary relationships
• How does scientific understanding change over time?

  • Science progresses
  • Our understanding evolves