Chapter 26

Question 1

Systematics

Answer 1

Discovering, organizing, classifying and interpreting biological diversity

Question 2

Phylogenetics

Answer 2

Investigates the evolutionary history and relationships of extant organisms. Phylogenetic inference must be based on homologous character states

Question 3

Nodes

Answer 3

Correspond to past speciation events on trees

Question 4

Convergent Evolution

Answer 4

Analogous characteristics can confound interpretations of similarities. Molecular data is usually better but not perfect for resolving evolutionary relationships

Question 5

False Tree vs. True

Answer 5

See review and slides

Question 6

Homologous

Answer 6

Derived from common ancestor (hair in example)

Question 7

Analogous

Answer 7

Evolved independently (flight). Don’t share a common ancestor.

Question 8

Challenges with determining Phylogeny (4)

Answer 8

• hard to compare vastly different organisms
• unicellular and simple organisms have few features for comparison
• many lineages lack good fossil records
• relationships are easily confounded by convergent evolution

Question 9

Phylogenetic Trees (4)

Answer 9

• Shared homologous characters are used to construct them
• Mostly molecular nowadays
• Compare homologous regions of DNA and measure changes in DNA sequences
• Measures genetic distances

Question 10

Cladistics

Answer 10

• Common ancestry is the primary criterion for classifying organisms.
• 3 Groups: Monophyletic, paraphyletic, polyphyletic

Question 11

Monophyletic

Answer 11

Ancestral species and all descendants

Question 12

Paraphyletic

Answer 12

Some but not all descendants

Question 13

Polyphyletic

Answer 13

Includes species from different ancestors