Week 1

Question 1

Fisher

Answer 1

The modern synthesis

several genes can contribute to a single trait

Question 2

Positive selection

Answer 2

NS that increases the frequency of a favourable allele

Question 3

Negative selection

Answer 3

NS that decreases the frequency of a deleterious allele

Question 4

balancing selection

Answer 4

acts to maintain two or more alleles in a population

Question 5

stabilising selection

Answer 5

maintains the status quo and acts against extremes

Question 6

directional selection

Answer 6

leads to a change in a trait over time

Question 7

artificial selection

Answer 7

form of directional selection

successful genotypes are selected by breeder, not through competition

Question 8

Disruptive selection

Answer 8

operates in favour of extremes and against intermediate forms

Question 9

intrasexual selection

Answer 9

members of one sex compete with one another for access to the other sex (fighting)

Question 10

intersexual selection

Answer 10

females choose thier mates

males compete for the attention of females with bright colours and advertisement displays

Question 11

biological species concept

Answer 11

species are group of actually or potentially interbreeding populations that are reproductively isolated from other such gorups

Question 12

Morphospecies concept

Answer 12

members of same species usually look alike, have similar DNA sequences that are distinct from other species

Question 13

cryptic species

Answer 13

organisms that had been traditionally considered as belonging to one species because they look similar, but turn out to belong to two species because of a distinction at the DNA sequence level

Question 14

ring species

Answer 14

species with populations that are reproductively but not genetically isolated
gene exchange occurs indirectly through intermediate populations

Question 15

ecological species concept

Answer 15

there is a one-to-one correspondence between a species and its niche; impossible for two species to coexist in same location if their niches are too similar because competition will lead to extinction of one of them

Question 16

phylogenetic species concept

Answer 16

members of a species all share a common ancestry and fate; members of a species have one common ancestor; useful in asexual species; limited use

Question 17

Pre zygotic isolating factors

Answer 17

behaviourally isolated 
gametic isolation 
mechanical incompatibility 
temporal isolation 
geographic or ecological isolation

Question 18

post zygotic isolating factors

Answer 18

genetic incompatibilities

Question 19

two ways by which populations become allopatric

Answer 19

dispersal and vicariance

Question 20

dispersal

Answer 20

some individuals colonise a distant place far from the main source population

Question 21

vicariance

Answer 21

geographical barrier arises within a single population, separating it into two or more isolated populations
vicariance-derived speciation is easier to study as easier to date

Question 22

peripatric speciation

Answer 22

few individuals from a mainland population disperse to a new location remote from original population and evolve separately
change accumulates faster in the isolated populations than in original population (genetic drift more pronounced)

Question 23

Adaptive radiation

Answer 23

bout of unusually rapid evolutionary diversification in which NS accelerates the rate of both speciation and adaptation; Occurs when there are many ecological opportunities available for exploitation

Question 24

co-speciation

Answer 24

speciation that occurs in response to speciation in another species
host-parasite speciation

Question 25

sympatric populations

Answer 25

for speciation to occur sympatrically, NS must act strongly to counteract the homogenising effect of gene flow no geographical separation

Question 26

BSC does not apply to

Answer 26

asexual or extinct organisms

Question 27

speciation

Answer 27

occurs when two populations that are genetically diverging become reproductively isolated from each other cannot produce viable, fertile offspring together

Question 28

allopatric population

Answer 28

populations geographically separated from each other

Question 29

peripatric speciation is a type of

Answer 29

dispersal

Question 30

order of M

Answer 30

``` molar milli molar micro molar nano molar femto molar ```

Question 31

n=

Answer 31

CV

Question 32

m=

Answer 32

n x Mw

Question 33

Darwin's two observations

Answer 33

members of a population often vary in their inherited traits all species can reproduce more offspring than their environment can support (struggle for survival)

Question 34

what is changing over time in NS

Answer 34

the inherited traits of a POPULATION

Question 35

Darwin's two inferences

Answer 35

those with higher survival rate contribute more offspring to next generation accumulation of favourable traits in the population over many generations

Question 36

heritable variations in traits

Answer 36

is randomly produced through mutation and sexual reproduction