exam 1

Question 1

phonetic approach to evolutionary trees

Answer 1

grouping organisms based on current similarities

Question 2

cladistics approach to evolutionary trees

Answer 2

grouping organisms based on common ancestory, more common approach

Question 3

monophyletic

Answer 3

a common ancestor and all of their descendants

Question 4

paraphyletic

Answer 4

a common ancestor and some but not all of their descendants

Question 5

polyphyletic

Answer 5

groups of organisms not sharing a common ancestor

Question 6

Occam’s razor

Answer 6

parsimony; the idea that the evolutionary tree with the fewest steps is most likely correct because the odds of convergence and regression are low

Question 7

polytomy

Answer 7

not enough information is available to separate two groups or to determine where the two groups diverged

Question 8

homologies

Answer 8

shared morphological or molecular traits; fundamental similarities underlie the physical differences ex: limb structure

Question 9

plesiomorphies

Answer 9

ancestral homologies

Question 10

apomorphies

Answer 10

derived homologies

Question 11

autoapomorphies

Answer 11

apomorphies unique to a specific group

Question 12

synapomorphies

Answer 12

apomorphies shared among a small group, most commonly used to build cladistic trees

Question 13

theory of special creation

Answer 13

organisms were created individually by a creator and never change

Question 14

theory of descent with modification

Answer 14

microevolution, macroevolution, speciation, and species derived from shared ancestory

Question 15

micro evolution

Answer 15

species have minor changes throughout time, proved by selective breeding, variation creates differential success, and vestigial structures

Question 16

speciation

Answer 16

lineages split and diverge into new species,

Question 17

macro evolution

Answer 17

over long periods of time, new forms of life rise from the old; proven by fossils which prove extinction, succession, and transitional forms

Question 18

vestigial structures

Answer 18

a body part that has lost function and become useless in one species but remains functional in closely related species ex: the human coccyx

Question 19

3 stages of speciation

Answer 19

1. a single population
2. 1 population divided into interbreeding subpopulations
3. formation of distinct populations with limited interbreeding
   ex: sickle backs

Question 20

species

Answer 20

population or group of populations capable of interbreeding

Question 21

ring species

Answer 21

a population found in all stages of speciation in a geographical ring, when thought of as a clock 12 and 1 cannot interbreed but all other neighboring species can ex: black backed and herring gulls

Question 22

law of succesion

Answer 22

pattern of similarities between fossils and extant groups in the same geographical areas

Question 23

transitional forms

Answer 23

species seemingly halfway between other species demonstrating evolution, help test the hypotheses of evolution ex: tiktaaluk

Question 24

processed pseudogenes

Answer 24

nonfunctional copies of normal genes that originate when processed mRNAs are accidentally reverse transcribed and placed back in the genome lacking introns and promoters; develop mutations over time making it possible to predict the age

Question 25

evolution requires

Answer 25

fidelity: genetic material is passed unchanged & mutability: genetic material can change

Question 26

repetetive DNA

Answer 26

coding and noncoding regions of DNA are repeated

Question 27

point mutations

Answer 27

single nucleotide substitutions

Question 28

missense mutation

Answer 28

SNP that results in the change of a single amino acid

Question 29

nonsense mutation

Answer 29

changes a normal amino acid to a stop codon

Question 30

synonymous mutation

Answer 30

silent, no change in the amino acid sequence

Question 31

frameshift mutation

Answer 31

insertion or deletion of a base pair causing the reading frame to shift resulting in a completely different code

Question 32

macromutations

Answer 32

large mutations altering up to whole chromosomes

Question 33

inversions

Answer 33

2 breaks in DNA, a 180 degree rotation and reinsertion preventing crossing over

Question 34

translocations

Answer 34

exchange of segments by non homologous chromosomes

Question 35

polyploidy

Answer 35

increasing the number of chromosomes often due to failure of meiotic division

Question 36

autotetraploidy

Answer 36

4N gametes combining from a species, typically not viable

Question 37

allotetraploidy

Answer 37

hybrid between 2 species, more likely to be fertile and viable, often acting as an instant speciation event

Question 38

gene duplication events

Answer 38

occur via unequal crossing over by putting 2 alleles of the same gene on one chromosome

Question 39

paralogous

Answer 39

2 or more genes in the same genome that share a common ancestor through speciation ex: alpha and beta hemoglobin

Question 40

orthologous

Answer 40

2 or more genes in different species that share a common ancestor

Question 41

hardy weinberg requirements

Answer 41

no mutation, no selection, no migration, random mating, and an infinite population

Question 42

deep homology

Answer 42

genes shared across a wide variety of groups

Question 43

mutation

Answer 43

a weak evolutionary force, provides material for evolutionary change but must be acted upon by another force for evolution to occur

Question 44

fitness

Answer 44

variation in the ability to survive and reproduce, measured by fecundity: number of offspring

Question 45

relative fitness

Answer 45

fitness in relation to other genotypes of the same gene

Question 46

deleterious recessive allele

Answer 46

dominant allele becomes fixed, highest mean fitness when p=1

Question 47

deleterious dominant allele

Answer 47

recessive allele becomes fixed, highest mean fitness when p=0

Question 48

overdominances

Answer 48

heterozygous advantage, both alleles even out around 0.5 highest mean fitness when p=0.5, stabilizing selection

Question 49

underdominance

Answer 49

homozygous advantage, whichever allele has the higher starting frequency becomes fixed, highest mean fitness when p=1 or 0, disruptive selection

Question 50

polygenic characters

Answer 50

coming from multiple loci, more difficult to determine models for so phenotypes are used

Question 51

frequency dependant selection

Answer 51

the most common phenotype is selected against often flipping back and forth until stabilizing ex: fish with one sided mouths

Question 52

multiple niche polymorphism

Answer 52

multiple forms of a single species exist to fill different ecological niches, requiring a heterogeneous environment ex: large and small billed finches