topic 4

Question 1

systematics

Answer 1

theory and practice of classifying organisms based on evolutionary history

Question 2

phylogeny

Answer 2

evolutionary relationships between organisms, shown in a phylogenetic tree

Question 3

importance of phylogenetic trees

Answer 3

organize biological diversity, visualize evolution, streucture classifications, guide research, connect multiple fields of biology, enable predictions

Question 4

data used to infer phylogenies

Answer 4

morphological data (physical traits), and molecular data (only for extant species)

Question 5

sister taxa

Answer 5

two descendants that split from the same node

Question 6

basal taxon

Answer 6

early divergence from the phylogenetic tree

Question 7

rooted phylogenetic tree

Answer 7

one branch that represents the common ancestor of all taxa on the tree

Question 8

polytomy

Answer 8

a branch from which more than two groups emerge

Question 9

what does polytomy indicate

Answer 9

lack of data or rapid speciation

Question 10

clades

Answer 10

groups that include an ancestor and all its descendants

Question 11

difference between cladograms and phylograms

Answer 11

phylograms depict evolutionary patterns AND branch lengths represent evolutionary change

Question 12

homology

Answer 12

traits that are similar because of descent from a common ancestor

Question 13

analogy

Answer 13

independently developed traits as an adaptation to similar environments (convergent evolution)

Question 14

how to separate homology and analogy

Answer 14

corroborrating evidence, trait complexity (more complex are homologus)

Question 15

ingroup vs outgroup

Answer 15

ingroup = group being studied, outgroup = related, earlier diverged species

Question 16

characters (homologous traits)

Answer 16

anatomical, physiological, molecular features used to compare taxa

Question 17

character states

Answer 17

observed variations of a character, used to determine evolutionary changes

Question 18

monophyletic groups

Answer 18

when a group contains an ancestor, all its descendants, no unrelated taxa
AKA a clade

Question 19

paraphyletic group

Answer 19

a group with a common ancestor that’s missing some of its descendants

Question 20

polyphyletic group

Answer 20

includes distanty related taxa but does not include the common anscestor of all group members (picks up an extra)

Question 21

causes of polyphyletic groups

Answer 21

incorrect taxonomic classifications, absence of fossil records, multiple common ancestors

Question 22

shared derived characteristics

Answer 22

synapomorphies, traits that mark a clade (unique to that ingroup)

Question 23

shared ancestra characters

Answer 23

symplesiomorphies, traits shared by taxa of a clade and in earlier clades

Question 24

maximum parsimony

Answer 24

the tree with the fwest evolutionary changes is more likely

Question 25

maximum liklihood

Answer 25

most likely evolutionary change is probably what happened