test 2: speciation

Question 1

gene pool

Answer 1

alleles in a population

Question 2

large gene pool

Answer 2

good variability, can survive

Question 3

small gene pool

Answer 3

less variability, less likely to survive

Question 4

harvey-weinberg equilibrium assumptions (artificial baseline)

Answer 4

• large pop size
• no migration
• no mutations
• random mating
• no natural selection

Question 5

why do we have an artificial baseline for harvey-weinberg?

Answer 5

represents stability of gene pool, any change usually results in evolution

Question 6

harvey-weinberg equilibrium equation

Answer 6

p^2+2pq+q^2 = 1
p+q = 1

individual scale = natural selection
pop scale = evolution

Question 7

types of polymorphism

Answer 7

genetic and balanced

Question 8

genetic polymorphism

Answer 8

different genetic alleles, wide variation

Question 9

balanced polymorphism

Answer 9

stable frequencies of two or more forms, heterozygote advantage (ex: sickle cell anemia)

Question 10

natural selection

Answer 10

• adaptions as a result of selective pressure
• relative contribution to next generation’s gene pool
• acts on physical traits, metabolism, physiology, behavior

Question 11

3 modes of natural selection

Answer 11

directional (change fur colour), disruptive (multiple fur colours), stabilizing (one very specific shade of certain colour)

Question 12

directional

Answer 12

selection happens for extreme, during environmental change

• competition from other species (ex: peppered moth)
  graph: peak shifts

Question 13

disruptive

Answer 13

intermediates are selected against
ex: peppered moth in region with varied pollution
graph - peak splits into two

Question 14

stablilizing

Answer 14

selection against extremes, prefers intermediates
happens in stable environments
ex: human birth weight a specific range
graph - peak is compressed

Question 15

mating

Answer 15

intrasexual, intersexual,

Question 16

intrasexual

Answer 16

one sex competes for the other

• direct comp (fighting)
• males patrolling large group of females
• harem system

Question 17

intersexual

Answer 17

females choose showy male

• traits related to good genes
• can also be resource related
• show sexual dimorphism (male “choose me”, females more bland)

Question 18

circumventing the competition

Answer 18

cheaters: sneaker squids

successful enough to not die out, but not enough to drive away dominant males

Question 19

morphological species concept

Answer 19

concept is inaccurate and not reliable

(group of organisms that have same morphology = anatomy) easy to make mistakes

Question 20

biological species concept

Answer 20

group of actual or potential interbreeding natural populations, fertile offspring & reproductive isolation

• natural pop with some gene flow
• concept has problems, but better than morphological species concept

Question 21

allopatric speciation

Answer 21

populations are separated geographically, over time you get genetic drift/new mutations and selection for particular environment

Question 22

sympatric speciation

Answer 22

populations in same area

• habitat difference
• host specificity (mutations in hosts can cause a new species)
• chromosomal speciation (chromosome changes result in new species)

Question 23

pre-zygotic barriers

Answer 23

habitat isolation, temporal, mechanical, gametic, behavioural

Question 24

post-zygotic barriers

Answer 24

reduced hybrid viability, reduced hybrid fertility, F@ generation feeble/sterile

Question 25

habitat isolation

Answer 25

never meet

Question 26

temporal isolation

Answer 26

different reproductive times

Question 27

behavioural isolation

Answer 27

doing the right dances, having the right morphs

Question 28

mechanical isolation

Answer 28

pieces need to fit together

Question 29

gametic isolation

Answer 29

egg and sperm, enzymes need to cooperate

Question 30

reduce hybdrid vitality

Answer 30

offspring won’t survive to mating season

Question 31

reduced hybrid fertility

Answer 31

offspring is sterile, cannot reproduce

Question 32

hybrid breakdown

Answer 32

survives one generation, but not 2nd

Question 33

gradualism

Answer 33

species change over time, one form evolves slowly into a new form

Question 34

punctuated equilibrium

Answer 34

long periods of no change; short periods of evolution with major environmental change; once sub species buds off it changes little

Question 35

phylogenies

Answer 35

compare relationships to determine evolutionary history of species or group (who is closer, when did the brand off occur…)

Question 36

systematics

Answer 36

classification and evolutionary relationship use taxonomy

Question 37

hierarchy of classification (large to small)

Answer 37

domain
kingdom
phylum
class
order
family
genus
species

Question 38

scientific names are binomial

Answer 38

first part - genus

second part - species

Question 39

who set up phylogenetic trees?

Answer 39

linnaeus

• each level called a taxon
• done both for sake of knowledge and problem solving

Question 40

analogy

Answer 40

convergent evolution (phylogenetic trees always divergent)

Question 41

homology vs analogy

Answer 41

homology - true shared ancestry, divergent
analogy - similarity, convergent
depends on feature being examined (ex: pentdactyl limb vs development of flight)