Lecture 17- Parsimony and Genes

Question 1

maximum parsimony

Answer 1

assumes that the tree that requires the fewest evolutionary events is the most likely; fewer branches, no disappearance or reemergence of characters

Question 2

The principle of maximum likelihood

Answer 2

given certain rules about how DNA changes over time, a tree can be found that reflects the most likely sequence of evolutionary events

Question 3

gene duplication

Answer 3

increases the number of genes and the genome, providing more opportunities for evolutionary change

Question 4

gene families

Answer 4

groups of related genes within a genome, results from repeated gene duplications

Question 5

homologous genes

Answer 5

genes inherited by two species that evolved from the same ancestor

Question 6

orthologous genes

Answer 6

result of a speciation event and occurs between genes found in different species; equivalent functions in different organisms

Question 7

paralogous genes

Answer 7

results from gene duplication and occurs between gene copies within a species; multiple copies of these genes ave diverged from one another within a species

Question 8

genome evolution

Answer 8

lineages that diverged long ago share MANY orthologous genes

Question 9

molecular clock

Answer 9

used to estimate the absolute time of evolutionary change; based on observation that some genes evolve at a constant rate; assumption is that the number o fnucloetide substitutions is proportional to the time since a. split from a common ancestor for orthologous genes or b. gene duplication for paralogous genes

Question 10

limitations of molecular clock

Answer 10

some genes evolve in irregular bursts, rate of evolution deviates occasionally, same gene may evolve at different rate sin different taxa, some clocklike genes evolve at drastically different rates

Question 11

differences in clock speed

Answer 11

neutral= constant, critical to survival harmful= slow, less critical neutral=faster

Question 12

carolus linnaeus kingdom classification

Answer 12

2, plantae or animalia

Question 13

robert whittaker classification

Answer 13

5, based on cell structure, body organization, mode and source of nutrition; monera, protista, fungi, plantae, animalia

Question 14

carl woese classification

Answer 14

3, archae, bacteria, eukarya (plantae, fungi, animalia)

Question 15

horizontal gene transfer

Answer 15

the movement of genes from one genome to another, occurs by exchange of plasmids, viral infection, fusion of organisms; conjugation, transformation, transduction, vesiduction; evolution of prokaryotes and eukaryotes