10.3 - Phylogeny

Question 1

Define phylogeny and phylogenetics.

Answer 1

Phylogeny: Evolutionary relationships between organisms

Phylogenetics: Study of evolutionary history of groups of organisms

• Reveals how closely related organisms are
  
  • reveals which groups organisms belong to

Question 2

Discuss the features of phylogenetic (evolutionary ) trees.

Answer 2

• Represents evolutionary links between organisms
• Branched diagrams showing the evolution of species from a common ancestor
• Produced by looking at similarities and differences between organisms (physical/genetic) → evidence gained from fossils

Descendant organisms at the tip of the tree

Nodes represent common ancestors

2 descendants from the same node are called sister groups

Question 3

List the advantages of phylogenetic classification.

Answer 3

• Doesn’t require reference to Linnean Classification
• Changes some groups of classification based of phylogeny
• Produces continous tree - not discrete taxonomic groups where scientists are forced to shoe horn organisms into groups (they may not fit in)
• Hierachy in Linnean Classification is misleading - implies groups of same rank are equivalent