Phylogeny (d)

Question 1

What is phylogeny?

Answer 1

The evolutionary relationships between organisms

Question 2

What is phylogenetics?

Answer 2

The study of the evolutionary history of groups of organisms. Reveals which group a particular organism is related to and how closely related these organisms are.

Question 3

What is a phylogenetic tree?

Answer 3

(Or an evolutionary tree) A diagram used to represent the evolutionary relationships between organisms. They are branched diagrams which show common ancestry.

Question 4

Describe phylogenetic trees

Answer 4

• Earliest species at the base of the tree + most recent species at tips of the branches
• Phylogenetic species concept - species at the end of a branch
• The closer the branches, the closer the evolutionary relationship.

Question 5

How are phylogenetic trees produced?

Answer 5

They are produced by looking at similarities and differences in species’ physical characteristics + genetic makeup, with fossil evidence

Question 6

Relationship between classification and phylogeny

Answer 6

• classification and phylogeny can occur with no knowledge of each other
• classification systems now account for phylogeny - it confirms the groups are correct or shows causes for groups to be changed

Question 7

Advantages of phylogenetic classification

Answer 7

• phylogeny produces a continuous tree rather than discrete taxonomical groups, with no pressure to put organisms into a specific group that they do not quite fit
• hierarchal nature of Linnaean classification can be misleading as it implies different groups within the same rank are equivalent. e.g. in terms of length of history or in terms of levels of diversity + different degrees of biological differentiation