Evolution SJ

Question 1

name 2 things that are evidence for evolution?

Answer 1

1) diversity

2) adaptation

Question 2

what are homologous characters?

Answer 2

traits inherited from a common ancestor but may now serve different functions

Question 3

define gene frequency

Answer 3

proportional representation of a gene in the population

Question 4

3 rules of mendelian inheritance

Answer 4

1) heredity is not blending
2) acquired characters are not inherited
3) it does not produce a change in gene frequency

Question 5

what is the hardy Weinburg equilibrium?

Answer 5

gene frequency in a population that is not evolving - no change in gene frequency

Question 6

5 conditions for hardy weinburg

Answer 6

1) infinite population size with no genetic drift
2) no mutation
3) mendelian inheritence
4) no selection
5) random mating

Question 7

what is sexual selection?

Answer 7

traits which favour males/females getting mates e.g attractiveness traits

Question 8

definition of adaptation

Answer 8

evolutionary change that fits an organism to its habitat

Question 9

3 factors necessary for selection

Answer 9

1) multiplication - struggle for existence
2) variation
3) inheritence

Question 10

what are discontinuous characters?

Answer 10

determined by one set of genes - distributions don’t overlap

Question 11

what are continuous characters?

Answer 11

determined by multiple genes

Question 12

define neodarwinism

Answer 12

natural selection + mendelian inheritence

Question 13

What is directional selection?

Answer 13

the mean value moves

Question 14

what is stabilising selection?

Answer 14

the variation is reduced and the mean value stays the same

Question 15

what is disruptive selection?

Answer 15

no intermediate - two distinct groups

Question 16

describe batsman mimicry

Answer 16

certain organisms mimic the look of others which have feature to defend against predators e.g. wasps have stings so predators learn to stay away so others without this ability mimic the look or wasps

Question 17

what is temporal environmental variation?

Answer 17

change in weather conditions causing organisms to adapt

Question 18

define fitness

Answer 18

genetic contribution to subsequent generations

Question 19

how can fitness be measured

Answer 19

as lifetime reproductive sucess

Question 20

what is intrasexual selection?

Answer 20

between a gender e.g. males stronger to fight other males

Question 21

what is inter sexual selection?

Answer 21

between the genders - males attracting females by good genes and access to resources

Question 22

what is polyandry?

Answer 22

when a female has many sexual partners

Question 23

what is monogamy?

Answer 23

one partner no sexual dimorphism

Question 24

what is polygamy?

Answer 24

when males and females have multiple sexual partners - sexual dimorphism

Question 25

what is polygyny?

Answer 25

when a male has many sexual partners

Question 26

describe altruistic behaviour?

Answer 26

behaviour which benefits other individuals at a cost to the altruistic individual

Question 27

the rate of individual selection is determined by...

Answer 27

the length of a generation

Question 28

the rate of group selection is determined by...

Answer 28

the length of a groups generation

Question 29

how did altruism evolve?

Answer 29

it is selfish at the level of the gene - altruistic individuals help other altruistic individuals so the altruistic gene continues in population

Question 30

what is hamiltons rule?

Answer 30

rb>C

Question 31

what is kin selection?

Answer 31

where helping kins breed has same genetic output as breeding itself

Question 32

what is micro evolution?

Answer 32

changes within a species

Question 33

what is speciation?

Answer 33

splitting one species into two

Question 34

explain gene flow

Answer 34

exchange of genes between populations as a result of movement and interbreeding of individuals

Question 35

what are 2 theories of speciation?

Answer 35

1) divergence - species adapt to different environments | 2) reproductive isolation - populations can't interbreed

Question 36

what is allopatric speciation?

Answer 36

isolation then divergence - environmental change causing different selection pressures

Question 37

what is sympatric speciation?

Answer 37

divergence then isolation - disruptive selection outweighs the effect of gene flow

Question 38

what is gradualism?

Answer 38

natural selection acting on a species to produce a gradual change in a species until speciation occurs

Question 39

an example of a good fossil record?

Answer 39

solenhofen limestone - lake with no oxygen so bodies didn't decompose

Question 40

what is divergent evolution?

Answer 40

when lineages split and separate but share a common ancestor

Question 41

what is convergent evolution?

Answer 41

not closely related species all exploiting similar resources

Question 42

what is adaptive radiation?

Answer 42

the evolution of character that allow exploitation of a new habitat

Question 43

what is mass extinction?

Answer 43

a period of geological time when extinction rate peaks

Question 44

what is local extinction?

Answer 44

loss of a population from a particular geographical area

Question 45

describe racial senescence

Answer 45

species undergo a lifecycle like individuals , orthogenesis- variation follows a particular direction

Question 46

3 reasons that may explain why species have gone extinct

Answer 46

1) racial senescence 2) competition from better adapted species 3) environmental change

Question 47

what are the 5 mass extinctions?

Answer 47

1) ordovician - marine invertebrates 2) devonian - marine invertebrates and fish 3) permian - marine invertebrates, trilobites , reptiles 4) triassic - marine invertebrates, freshwater fish, reptiles, insects 5) cretaceous - marine invertebrates, ammonites, marsupials, belemnites, plesiosaurs, Mosasaurs, Pterosaurs, Dinosaurs

Question 48

describe the cretaceous extinction and evidence for it

Answer 48

asteroid impact - KT boundary where fossils of dinosaurs are no longer found

Question 49

describe a selfish gene

Answer 49

anything that a gene can do to favour its own spread at the expense of others will be favoured by selection

Question 50

altruism is only favoured by evolution if...

Answer 50

it increases rate of spread of a gene

Question 51

describe dawkins green beard selection example

Answer 51

where altruistic genes are linked to an obvious phenotype so individuals act altruistically towards others with the same phenotype trait - doesn't require relatedness

Question 52

what is cooperative behaviour?

Answer 52

individuals cooperate for their own selfish reasons

Question 53

cooperation only evolves when...

Answer 53

the behaviour causes it to spread faster and increase the fitness of an individual

Question 54

what are 3 human acts causing extinction?

Answer 54

1) hunting 2) introduction of alien species 3) habitat loss by human activities e.g. logging

Question 55

what is phylogenetic niche conservatism?

Answer 55

species inherit their niches from their ancestors

Question 56

what is phylogenetic diversity?

Answer 56

the total amount of evolutionary history shared by a group of species

Question 57

which species are best to try and conserve from extinction?

Answer 57

- broad phylogenetic diversity because more closely related species share similar extinction risks - evolutionary distinct species to save them