all

Question 1

define adaptation

Answer 1

a characteristic that enhances the survival or reproduction of organisms relative to alternative character states

Question 2

are all traits adaptations?

Answer 2

no

Question 3

what happens at hardy Weinberg equilibrium?

Answer 3

gene frequencies don’t change and there is no evolution

Question 4

what are the 4 evolutionary forces needed to disrupt HWE and give a few points on each

Answer 4

1. mutation- random, new variation, heritable change in genetic material
2. genetic drift- random changes In unselected allele frequency, can lower heterozygosity, can cause isolated pop to diverge
3. migration- counteracts divergence and is due to drift
4. natural selection- drive changes in gene frequencies, fitness and adaptation focused

Question 5

define natural selection

Answer 5

differential survival and/or reproduction of classes of entities that differ in one or more characteristics

Question 6

what are entities?

Answer 6

genotype, pop, species

Question 7

define fitness

Answer 7

probability of survival X average number of offspring for a class of individuals

Question 8

define gene pool

Answer 8

total aggregate of genes in a pop at any one time

Question 9

define evolution

Answer 9

any change in gene frequencies, developing from earlier forms

Question 10

for what 3 reasons do we know natural selection exists?

Answer 10

1. correlations between trait and environment
2. responses to experimental change in the environment
3. correlations between trait and fitness component

Question 11

what is an example study of correlations between trait and environment and a justification for natural selection existing?

Answer 11

Endler 1980 study of Guppies- poecilia reticulata

- predicted that colouration and pattern differs between rivers due to predation rate

Question 12

what is an example study of responses to experimental change in environment?

Answer 12

Endler 1980 guppies

• tested with 10 ponds (high predation-4, low predation-4, control-2)
• guppies moved between ponds so no isolation
• no difference in spots per fish for black, yellow, red but was for blue and iridescent as under different selection pressures
• less spots when higher predation
• smaller spots on coarse gravel but when predation switch to large spots to match background

Question 13

what is the guppy example study of correlations between trait and fitness

Answer 13

endler 1980 guppies

• is an effect in fitness
• but when no predators number of spots kept rising and did opposite to background so must be +ve to being visible such as for sexual selection
• rarer pattern more attractive to females as more carotenoids= faster more viable sperm

Question 14

what is the locatello study example study of correlations between trait and fitness

Answer 14

2006

+ve to mating with orange males as those with more carotenoids had faster, more viable sperm

Question 15

what is the Hughes study example study of correlations between trait and fitness

Answer 15

2013
more of an effect is male is rare, making him more attractive
- negative frequency dependent selection

Question 16

what does the Kottler study suggest?

Answer 16

2018

suggests involvement of sexually antagonistic coevolution for correlation between trait and fitness

Question 17

what are 6 problems with detecting selection?

Answer 17

• consequences of physics/chemistry so the trait may not be adaptive (red blood cells red as consequence of iron in haemoglobin- not adaptation)
• genetic drift can spread traits
• ancestral state (selection pressure change quickly so adaptation may not longer be relevant)
• selection might not cause change even if acting
• selection may not be working at individual level
• linkage

Question 18

what is linkage?

Answer 18

• recombination during reproduction causing a genetic mashup

- 2 or more non-allelic genes inherited together as are located closely on same chromosome

Question 19

what is gene flow?

Answer 19

the transfer of genetic variation from 1 pop to another

Question 20

what is linkage disequilibrium?

Answer 20

alleles appearing together more often than you would expect by chance

Question 21

what is a chromosomal inversion?

Answer 21

DNA gets a loop/flip so recombination can’t affect these sequence of genes so alleles are locked in and passed on through generations

Question 22

what are hitchhiking alleles ?

Answer 22

If allele next to beneficial one selection will act on entire chunk of DNA so both alleles are passed on through

• selective sweep
• one allele appears beneficial but it isn’t and its frequency changes even though itself isn’t under selection

Question 23

give 3 reasons for linkage disequilibrium

Answer 23

• beneficial alleles group together
• structural changes such as chromosomal inversion
• hitch hiking alleles

Question 24

what is an example of hitchhiking alleles?

Answer 24

Atwoods experiment on E.coli in 1951
His+ allele: cell can make histidine
His- allele no histidine
- his allele hitchhiking due to association with advantageous mutation
- ‘His’ alleles respond to selection but aren’t under selection

Question 25

what did chan et al discover and when?

Answer 25

2012- evidence for selective sweeps in mice for body size genes

Question 26

what 5 things will natural selection NOT do?

Answer 26

- not always lead to adaptation - not always produce perfection - no always progress - not produce balances harmonies world - not consider ethics

Question 27

what is directional selection?

Answer 27

shifts overall population by favouring an extreme phenotypes (most common when environmental change and migration)

Question 28

give an example of directional selection

Answer 28

drug resistance in plasmodium falciparum - over time increase in malaria resistance to antibiotics due to increased use - 2014 study Nwakanma found high peak with use of antibiotic antifolate which was introduced 2005 - now resistance kept down by using ACT which is plant material combined with antibiotics

Question 29

what is divergent selection?

Answer 29

favouring variants of opposite extremes but not the intermediates - normally when 2 different environments between populations - if in same pop is disruptive selection

Question 30

what is the great tit example of divergent selection?

Answer 30

- females black stripe fades away - males black stripe reaches between feet - stripe made from melanin which is costly to produce - thicker stripe means better quality male as can provide more parents care and offspring

Question 31

what was Senar's study and when and what type of selection?

Answer 31

2010 using recapture technique - forest tits with a bigger stripe had survival increase - city tits found after a certain point no longer beneficial to have thick stripe and lower quality males may be forced here as less nutrients - urban tits smaller stripe may make them fitter - divergent selection between urban and rural great tits

Question 32

how does stabilising selection act + 2 example?

Answer 32

against extreme phenotypes and in favour of intermediates, narrowing genetic variation - human birth rate - Rundle 2012 drosophila serrata genici variation higher among low fitness individuals compared to higher

Question 33

what is heterosis?

Answer 33

hybrid vigour which improves the function or increased characteristics in hybrid offspring

Question 34

what is fluctuating asymmetry in fish?

Answer 34

phenotypic measure of how different the two sides of the fish are

Question 35

what is the inbreeding vs outbreeding in bluegill sunfish?

Answer 35

individuals with intermediate genetic variance had higher breeding success and lower fluctuating asymmetry - more asymmetry = higher fitness - more inbred and diverse fish had lower breeding success

Question 36

what is a combination of all 3 selection types example? (4 points and evidence for each type)

Answer 36

spade foot toads (spea multiplcata) - 2 morphs studies in infancy - omnivore: longer intestine, more teeth, bottom of water - carnivore: feed on shrimp, hover in water column - mark recapture technique by Martin and pfennig 2009 - DIVERGENT: intermediates less likely to survive with smaller body size, extremes more efficient feeders - DIRECTIONAL: carnivores favoured over omnivores by this selection as greater prop recaptured - STABILISING: intermediate form not lost when co-occuring with more dominant spea bombiforns and intermediate is favoured

Question 37

variation is necessary for selection but what can selection often reduce?

Answer 37

variation

Question 38

in what 4 ways are genetic variation and polymorphism maintained?

Answer 38

1. diploidy 2. gene flow 3. mutation 4. balancing selection (heterozygous advantage, frequency dependent selection)

Question 39

how does diploidy maintain genetic variation and polymorphism?

Answer 39

- 2 sets of chromosomes - hides genetic variation in recessive alleles of eukaryotes - 2 individuals with recessive alleles must mate for expression to be seen - detrimental or beneficial alleles may be hidden without being expressed - if environment changes and has beneficial phenotype selection favours so may have advantage over pop

Question 40

what can happen when moving between pops and what is an example?

Answer 40

can increase genetic variance | spade foot toads- when adults become toads enter new environment bringing genetic background

Question 41

what are the 2 main types of mutation and what does one of these branch off into?

Answer 41

somatic and germline | germline: block or point mutations

Question 42

what are block mutations?

Answer 42

affect entire chunks of chromosome (insertion, deletion, inversion, translocation, duplication)

Question 43

what are point mutations ?

Answer 43

occurs at 1 base (insertion, deletion, inversion, substitution)

Question 44

what does it mean if a point mutation is synonymous?

Answer 44

silent with no effect

Question 45

what does it mean if a point mutation is nonsynonymous?

Answer 45

missense: changes amino acid nonsense: stop codon produced frame shift: disrupts codon pattern

Question 46

what do all types of mutations add?

Answer 46

variation

Question 47

what does balancing selection do to the allele proportions?

Answer 47

keeps it them at the same level

Question 48

what are 2 examples of heterozygote advantage?

Answer 48

1. sickle cell anaemia in Africa: 1 copy= malaria resistance, 2 or 0 copies= sickle cell anaemia 2. connexion 26: builds up and thickens skin epidermis: 1 copy= more immune due to thickness and aids cell repair, 2 copies= deafness

Question 49

what are 4 critiques to answer: is heterozygote advantage likely to be common for balancing selection?

Answer 49

1. good adaptation should be fixed at 100% in pop asap but its not 2. what seems to be heterozygote advantage mightn't be 3. heterozygote advantage imposes 'load' on pop (may decrease overall fitness) 4. heterozygote advantage unstable due to duplication

Question 50

what did Sellis in 2011 argue?

Answer 50

that heterozygote advantage does make sense as need to be fit in heterozygous form first as is how it arises through mutation

Question 51

what is the selection coefficient?

Answer 51

(how much below fitness of pop- amount mutation affects fitness) - difference between mean relative fitness of individuals of genotype and of reference of genotype

Question 52

what allele types are generally less fit?

Answer 52

homozygote recessive

Question 53

what is associative overdominance?

Answer 53

increase in fitness of heterozygotes at neutral locus as is in linkage disequilibrium at locus under selection

Question 54

what is genetic load?

Answer 54

difference between maximum (1) and mean fitness

Question 55

what does a genetic load of 0.3 mean?

Answer 55

pop is working at mean fitness 3% below total fitness

Question 56

what is the genetic load of sickle cell anaemia?

Answer 56

0.1

Question 57

what is gene duplication?

Answer 57

event in which one gene gives rise to 2 genes that can't be operationally distinguished from one another

Question 58

what can make heterozygote advantage vulnerable?

Answer 58

gene moving from one locus to another further up so every individual has the gene in heterozygote form

Question 59

where is there evidence of duplication in genes?

Answer 59

genes controlling colour vision in humans

Question 60

what is frequency dependent selection and what would it be for -ve freq dep selection ?

Answer 60

the survival and reproduction of any one morph changes (declines=NFDS) if that phenotypic form becomes more common in environment

Question 61

what are 2 examples of positive frequency dependent selection?

Answer 61

- survival/reproduction increases in form more common MULLERIAN MIMICRY - poisonous individuals copy one another, more common the trait, more survive and come fitter CYTOTYPE EXCLUSION - plants can gain new chromosomes - need another plant of same ploidy level to mate - if more in environment, fitter individual

Question 62

does PFDS or NFDS maintain polymorphism?

Answer 62

NFDS

Question 63

what are 2 examples of NFDS?

Answer 63

- advantage of the rare BATESIAN MIMICRY - cheat mimics poisonous one, better to be rare so undiscovered by predator HOST PARASITE CYCLES - parasite evolves attack mechanism, host evolves defence

Question 64

what is the lake tanganyika cichlid example of NFDS? (Hori 1993)

Answer 64

- P.microplepsis - predatory with mouths facing different sides and eat chunks of flesh from prey fish - if one side more common with cichlids prey fish will become more defensive on that side - maintain max fitness when equal prop of each morph in pop - if 1 increases the other doesn't do as well

Question 65

- what % women and men are left handed - what are 3 results of it - what was suggested about it

Answer 65

- 10% W 12% M - lower height, reduced longevity, fighting/sports advantage - Raymon 1996 suggested NFDS

Question 66

what is the environmental tolerance of tropical species like?

Answer 66

- restricted in range - stable environment - more under threat if environment changes

Question 67

what are the 2 climatic variability hypothesis?

Answer 67

1. species with greater physiological tolerance to climatic variable can extend their distributions higher latitudes 2. species with low genetic variance are unlikely to have great physiological tolerance

Question 68

what is heritability and what can increase it?

Answer 68

prop of phenotypic variation in pop due to genetic differences - increasing genetic variance increases heritability

Question 69

what was the study on environmental tolerance in drosophila? (6)

Answer 69

kellermann 2009 - 2 subsets studied (global and tropical) - measured additive genetic variance - found more varied the genome the more tolerable - tropical less varies - genetic variance increases when more adapted to desiccation or cold - not due to inbreeding depression as all species have the same wing size so traits aren't showing the same pattern

Question 70

in what 3 main ways do species get around the issue of lack of genetic variation?

Answer 70

- mutation - phenotypic plasticity - transposable elements

Question 71

in terms of mutation how may adaptations arise?

Answer 71

single base pair mutation and spread rapidly

Question 72

how did mosquito culex pipiens become resistant to insecticide?

Answer 72

gene flow | single base pair mutation -> change in amino acid -> target site changed shape -> insecticide no longer works

Question 73

a) what did Zuk study in 2006 to do with mutations on O.orchracea and T.oceanicus? (6) b) what suggests where the mutation is ? c) where was the density of silent males found to be higher? d) where did the flat wings get closer to and why?

Answer 73

a) - parasitic fly buries its eggs in cricket - crickets usually give out call to attract females - 1991: 30% male crickets parasitised - 2001: one calling, not many around - 2003: many crickets but none calling - 2004: 121/133 males had flat wing which is silent so wing morph completely changed b) female can mate with flat wing male and produce normal male so suggests on X chromosome c) Kauai island of Hawaii d) closer to speaker with call emitted as believed females will gravitate to the sound so can intercept other males going here

Question 74

what did Mukai discover in 1972 on an experiment of drosophila?

Answer 74

as mutations accumulate mean variability decreases and variance among chromosome increased

Question 75

what was Kassen and Bataillon's study and when?

Answer 75

2006 - on P.fluorescens bacteria - total 655 mutations - 28 had +ve effect - on average -ve effect so selection has to work continuously against mutations to maintain fitness

Question 76

what is phenotypic plasticity and what can it allow for?

Answer 76

same genotype produced different phenotypes due to environmental conditions - allows for flexibility and variance - may allow persistence in new environment for long enough that selection can act

Question 77

what are 2 very brief examples of phenotypic plasticity?

Answer 77

hydrangeas- different colours due to different soil ph | drosophila- inverse relationship where the hotter the temp the smaller the body size

Question 78

explain Wijngaarden's study for phenotypic plasticity

Answer 78

Bicyclus anynana- squinting brown bush butterfly 2002 - temp affects morph: brighter in summer as mating season at this time - temp increases eye spot increases - tried to change reaction norm of species through artificial selection pressure - but mechanisms controlling plasticity not changed under artificial selection - plasticity buffers genotype from selection working on it

Question 79

what may be a constraint to adaptation?

Answer 79

plasticity can buffer genotypes from section acting upon it and if environment changes the genotypes may not longer be able to cope

Question 80

give 9 points about transposable elements

Answer 80

- may mean more of fitness landscape available - likely involved in genome evolution - group of genetic structures varied in response - hop around genome - previously thought to be detrimental - some jump to preferred spots linking to adaptability, causing new phenotypes to occur - can preadapt populations by generating genetic variation or phenotypic plasticity in source pop - stress during introduction of individuals into pop alters epigenetic control of TEs so gene regulation altered - new TE inserts can create genetic and phenotypic variation which can aid adaptation

Question 81

what are transposable elements like in mammals?

Answer 81

- no evidence of increased adaptability - significant amount of genome made up of them - may allow pops to explore fitness landscape in a shorted amount of time

Question 82

a) what is a fitness landscape in general and what does selection drive? b) what is dynamic fitness landscape c) static?

Answer 82

a) map of adaptive landscape where a bigger peak= higher fitness, selection only drives populations up a peak b) as fitness landscape changes populations evolve to track the peaks c) population evolves to only 1 peak

Question 83

what are the 3 evolutionary forces of a fitness landscape?

Answer 83

- selection: head to nearest area of peak fitness - drift: less power to drive species up a peak - mutation: species taken from 1 point to another on landscape

Question 84

who proposed the original fitness landscape and when?

Answer 84

Wright 1932

Question 85

what is the T.oceanicus cricket example of a fitness landscape?

Answer 85

1. singing males on 1 peak- song is adaptive 2. success of fly reduces fitness peak which constrains that adaptive path 3. mutation offers a jump to another peak

Question 86

most traits don't work in unison- what can correlated traits do?

Answer 86

hinder pathway of evolution

Question 87

what is pleiotropy?

Answer 87

where one gene affects more than one character/phenotypic trait

Question 88

what does the direction of evolution depend on?

Answer 88

genetic correlation

Question 89

what can genetically correlated traits be and what do they take longer to do?

Answer 89

constraint | longer to reach peak of landscape

Question 90

what Is the Galapagos finch example of correlated traits from 1977?

Answer 90

- drought caused decline in smaller seeds but larger seeds survived so was increase in seed size and hardness - beak size and bird weight increased after drought to utilise larger seeds - but bill length increased even though selection acting to make it smaller, because selection was so strong for bill depth

Question 91

- if the environment changes is it more beneficial to be positively or negatively correlated? - which has a narrower range of where species can sit within environment? - what happens if working against each other? - do they have the same mean and trait levels?

Answer 91

- positively - negatively - contains fitness of individual - same mean but at same environmental gradient different trait levels

Question 92

why is it important to figure out how traits influence each other?

Answer 92

how species evolve

Question 93

what are hybrid zones and give 6 points about them

Answer 93

where genetically distinct populations meet, mate, reproduce - challenges view of species and confuses taxonomists - can be asymmetric - congregate in areas of low density - can be barriers to gene exchange - show historical patterns - covers cline between 2 distinct pop of alleles

Question 94

for what 2 reasons are hybrid zones good to study?

Answer 94

- involved in nearly all speciation events (except polyploidy selection) - range of genotypes show genetic differences and selection pressures that separate taxa

Question 95

what is the distribution of the European hedgehog like and what are the 2 main species?

Answer 95

Erinaceus europaeus Erinaceus concolor - based on mtDNA 4 subgroups found in Europe (northward migration)

Question 96

what was the post glacial recolonisation? (6)

Answer 96

- most of Europe covered in glacier so species were in southern warmer refugia - facilitate persistence of components of biodiversity over millennia and under changing climates - after ice age glacier retreated and species followed it back up Europe - populations previously isolated met so many hybrid zones created - plants followed similar pattern - locating hybrid zones can infer a lot of species history

Question 97

list the 4 consequences of hybridisation

Answer 97

- indefinite - merge - reproductive isolation - third species

Question 98

what is the indefinite consequence of hybridisation? (5)

Answer 98

- some interaction between 2 pops in hybrid zone - selection maintains steep clines at some loci - could be tension zone - could move to area of low density - only if character differences favoured by different environments

Question 99

what is the merge consequence of hybrid zones? (4)

Answer 99

- pops and alleles merge becoming 1 pop - fitness of hybrids not lower than original pop - introgression and post zygotic barriers broken down - variation and distinction between 2 pops lost

Question 100

what is the reproductive isolation consequence of hybrid zones? (3)

Answer 100

- selection acts to keep pops apart - strengthening of barriers to gene exchange - large areas of genome protected from introgression

Question 101

what is the third species consequence of hybrid zones? (2)

Answer 101

- hybrids become reproductively isolated from original pop | - new species forms

Question 102

what is a cline?

Answer 102

a change in allele frequency over a geographical transect/hybrid zone

Question 103

what can we use cline characteristics to tell us? how does the cline differ if no gene flow or lots of gene flow?

Answer 103

about the mixing of populations such as shape, co-occurance and movement of cline NO gene flow: g=0 steep stepped cline LOTS: g=1 shallower cline

Question 104

what is the equation for cline shape?

Answer 104

W (directly proportional to) square root of d2/s W=width of cline d= dispersal/gene flow s= selection

Question 105

why was it believed that romans created a high dispersal and wide cline?

Answer 105

frequency of B allele in blood group declines in E to W gradient which reflects the invasions into Europe from Mongolia after roman empire collapse

Question 106

what is heterozygote disadvantage?

Answer 106

lower intrinsic fitness than either parent | - homozygotes are acting with each other and heterozygotes are unfit and so selection against them

Question 107

explain the Hoekstra example of a sharp cline

Answer 107

2004- rock pocket mice (C.intermedius) - 2 morphs with melanin causing black coloration - sampled at different locations of each substrate type - 4 amino acid variations cause the colour differences - some interbreeding - selection acts to keep coloured alleles in their areas - gene flow/dispersal smooths out changes in phenotype frequency at boundary - selection pressures strong from predation

Question 108

what type of hybrid zone do each of these show? - hedgehogs - rock pocket mice

Answer 108

- secondary | - primary

Question 109

what are the 2 types of hybrid zones?

Answer 109

PRIMARY: natural selection alters alleles in a continuous population - environment affects different loci in different places - likely a sharp cline - alleles change depending on environment - neutral alleles maintain similar level SECONDARY: formally allopatric species expand to meet again - clines expected to be in same place - even neutral alleles will change

Question 110

what is the mytilus edulis example of primary hybrid zones?

Answer 110

blue mussels - Ap94 allele increases amino peptidase 1 activity so higher amino acid conc in cell as are cleaved off of end of proteins - cline maintained by selection against Ap94 in environment and against gene flow from oceanic populations - the environment change causes the allele change - freq of allele increases as salinity increases

Question 111

what is the house mouse example for a secondary hybrid zone?

Answer 111

mus musculus macholan 2007 - 1800 mice at 105 sites on Germany border hybrid zone - change in morphology down centre of Europe of 2 morphs M.musculus and M.domesticus - 2 loci sampled - allozyme loci: different forms of enzyme do the same job- neutral - x-linked loci: under strong selection - neutral allele only affected by selection if hitchhiking alleles or under linkage disequilibrium - neutral allele has a larger cline width

Question 112

what is the European toads example for a secondary hybrid zone?

Answer 112

- western yellow bellied toad bombina variegate - eastern fire bellied toad bombina bombina - strong barrier to gene flow so even neutral genes influenced by selection - allozymes and morphological characteristics coincided

Question 113

what do clines move in response to and what does this influence?

Answer 113

strength of dispersal | influences shape and location of cline

Question 114

how may different alleles follow different pattens?

Answer 114

- B allele could be linked to A allele so a similar pattern seen - if B selectively neutral can move on its own, dissociating from original population - backcrossing can occur

Question 115

what is back crossing

Answer 115

hybrid crossed with parent so offspring can move across hybrid zone in different way to to A allele

Question 116

what is introgression and when may it occur?

Answer 116

movement of genes from 1 species or pop into another by hybridisation and backcrossing - can occur if selectively neutral where alleles merge into population

Question 117

what is pre zygotic isolation?

Answer 117

factors keeping individuals apart before egg and sperm meet (habitat, temporal, morphological, behavioural)

Question 118

what is post zygotic isolation and what are 3 types?

Answer 118

reproductive barrier after fertilisation - hybrid inviability - hybrid infertility - hybrid breakdown

Question 119

what is the genetic basis of a barrier?

Answer 119

dobzhanksy-muller model 1934 - genes interact with everything on genome - if allele evolves in 1 pop that has never mixed with another and is introduced to it there is potential conflict between alleles, disrupting each others function - incompatibilities can arise from background mutations - over time they can build up

Question 120

what does mating preference have to be linked to to lead to reproductive isolation and speciation?

Answer 120

adaptive trait

Question 121

what is the direct system of mating preference link to adaptive trait and an example?

Answer 121

- same gene as mating preference is adaptive and affects the preference - referred to as magic traits or multiple effect traits - male Panama butterflies spend more time courting those with the same wing type

Question 122

what is the lake Victoria cichlid example fo direct system of mating preference link to adaptive trait?

Answer 122

- shallow water: blue colour - deeper water: red colour - at different depths males evolve different colours due to eye adaptations - easier to see red females in deeper water - female preference for males based on same trait

Question 123

what is the indirect system of mating preference link to adaptive trait ?

Answer 123

adaptive gene linked to one affecting mate preference so adaptive and mate choice are on 2 linked loci - selection against recombination - females only mate with males with adaptive trait - example of linkage disequilibrium

Question 124

what is the reproductive character displacement from reinforcement hypothesis and who suggested it?

Answer 124

Alfred Russell Wallace - selection for pre-zygotic isolation barrier is due to selection against mating, creating unfit hybrids - theoretically completes speciation when post zygotic barriers are incomplete - can only happen in sympatry - often more obvious in selected traits - if barrier not there individuals may mate with others from a different population - selection acts to put a barrier there to stop groups breeding when living in the same region

Question 125

what is the allopatry and sympatry between the pied flycatcher and collared flycatcher?

Answer 125

- females are brown - males of the 2 species look similar so in sympatry pied flycatcher changes his plumage to become brown like female in order to stand out from other flycatcher to be reproductively successful - indirect system - mate preference allele needs to change as well as the adaptive trait changing (theory of reinforcement)

Question 126

what did price and bouvier discover about birds in 2002? (7)

Answer 126

- collected data from literature about recorded matings - individuals less closely related and more diverged fail to produce fertile offspring and often sexes are inviable - only 62% of same species produced fully fertile offspring - standard cytochrome b clock estimated time of divergence as 2% per million years - species with infertile hybrids last shared common ancestor 7mya - 5mya for passerines , 17mya for non passerines - strong support for haldane's rule

Question 127

what is haldanes rule?

Answer 127

when a cross produces inviable or sterile offspring the heterogametic sex is more strongly affected

Question 128

why may female birds suffer more from inviability?

Answer 128

they are the heterogametic sex ZW rather than ZZ

Question 129

what did the coyne study of drosophila find?

Answer 129

- different combinations of chromosomes leads to different effects - X chromosome has major effect on sperm motility - clear difference in isolation for sympatric and allopatric taxa - sympatric more likely to have diverged from each other

Question 130

where does pre zygotic isolation evolve faster and what can speed it up?

Answer 130

sympatric pairs | reinforcement

Question 131

what are speciation genes?

Answer 131

genes which cause reproductive isolation on their own

Question 132

what is the current speciation hypothesis?

Answer 132

1. small adaptive divergence 2. divergent areas grow via linkage 3. genomes diverge so much that interbreeding very reduced 4. isolation

Question 133

in drosophila mauritiana and drosophila simulans: a) what differs between them b) how may it have evolved c) what is it similar in structure to d) what does asymmetry in sequence evolution suggest e) where is the biggest ratio of change and whats it acting for

Answer 133

a) OdsH which causes sterile males to appear in D.simulans when allele moved to them b) gene duplication c) ancestral gene unc-4 d) differential functional roles e) in non synonymous substitutions- selection acting for mutations changing function of protein

Question 134

what is likely to contribute to species differentiation where the divergence is likely due to selection?

Answer 134

duplicated genes that are in the process of evolving into new functions at the time of species separation

Question 135

give 6 points about what speciation is?

Answer 135

- speciation is a multi level process unfolding through time and space - populations subjected to demographic processes and redistributed in space - periods of physical separation will alter with periods of gene flow - different mechanisms acting at different phases of divergence process - barrier loci contributing to reduction in gene flow can accumulate gradually until diverging genomes eventually won't mix any further - introgression can favour divergence or hybridisation may generate new isolated populations

Question 136

what are 4 contributors to speciation?

Answer 136

chance, ecology, reinforcement, sexual selection

Question 137

what are 3 examples of chance mutations?

Answer 137

- spontaneous polyploidy speciation - long term drift can lead dobzhanksy muller incompatibilities - mutation order speciation - founder effect speciation

Question 138

what is mutation order speciation?

Answer 138

- different populations find different genetic solutions to the same selective problem - different alleles due to different selection pressures - ecology evolved but doesn't favour divergence - divergence is random

Question 139

what is founder effect speciation and what is it also known as?

Answer 139

peripatric speciation - small satellite population diverges from large ancestral population usually by isolation and inbreeding forms a new population

Question 140

what is the paradise kingfisher example for founder effect?

Answer 140

- each island of papa New Guinea has their own species that are morphologically different to each other - some left the ancestral pop to other islands - dependent on chance as to which birds left the mainland

Question 141

give 9 points about polyploid speciation

Answer 141

- more than 2n - important in plant species more so than sexually reproducing taxa - often associated with reproductive isolation and morphological differences - instant new species (salutational ) - usually formed by failure of division in meiosis - some fish polyploid - plains viscacha rat the only mammal - 15% angiosperms show polyploid speciation - 31.37% ferns

Question 142

what are 4 advantages of polyploid speciation?

Answer 142

- heterozygote advantage - extreme phenotypic traits - reproductive isolation - duplication on big scale

Question 143

what can polyploid hybrids have in terms of the fitness landscape?

Answer 143

more of it opened up to them and can jump between peaks on the adaptive landscape

Question 144

whats the difference in genetic variation between homoploid and polyploid hybrids?

Answer 144

polyploid have less genetic variation as are fewer of them

Question 145

what can divergent selection between environments cause?

Answer 145

barriers to gene flow

Question 146

what 3 things are ecology mechanisms related to?

Answer 146

- environmental differences (habitat structure, climate, resources) - ecological interactions (disease, competition, behavioural interference) - sexual selection

Question 147

what was found for the ecological differences for Timema cristinae

Answer 147

- 1 resembles pine needle and the other is on open flat leaves so is fatter and flatter - show reproductive isolation even though the same species - Nosil investigated which aspect of ecology influencing the most - different host pairs show more isolation than same host pairs

Question 148

what are pea aphids dependent on?

Answer 148

2 morphs: some live on Alfalfa and some on clover | if you switch them over their fitness decreases

Question 149

what are monkey flowers dependent on?

Answer 149

habitat type with a coastal form and inland form but if you switch not all will survive to flowering stage

Question 150

what is the howea plants example for environmental differences? (6)

Answer 150

- lord howe island off coast of Australia - 2 forms, thatch palm and curly plam covering island live close together coming from 1 ancestral population - only 6 adult hybrids ever found on island - only 4 loci found to differ on genome more than expected by chance - isolated by different habitats such as different soil types even though are close together and have different flowering times (pre zygotic barrier) - sympatric speciation most likely caused by ecology

Question 151

what are examples of ecological interactions and 3 points about it?

Answer 151

- disease, competition, behavioural performance - normally in sympatry - can be ghost of competition past - can cause ecological character displacement

Question 152

what is the ecological interaction for interspecific competition in sticklebacks?

Answer 152

- 2 morphs: brook stickleback and ninepin stickleback - brook show characteristics of benthic living rather than pelagic when in sympatry with ninepin and develop stronger jaws and wider bodies - brook in sympatry and allopatry with nine spine exhibit different growth forms - will separate 2 species but also cause divergence of 2 population of brook sticklebacks

Question 153

what is the ecological interaction for intraspecific competition in anolis sagrei lizard?

Answer 153

- dulap involved in sexual selection to attract mates - inhabit many islands and like to sit on different perches - like to be on perches visible to females - largest and smallest favoured in the population - disruptive selection and ecological interactions

Question 154

give 4 points about reinforcement

Answer 154

- change in mating trait which in sympatry acts to make a distinction - some argue could also be a starting point: cascade reinforcement - mechanism to finish speciation process - for reinforcement to act there must be enough gene flow for hybrids to exist and be selected against

Question 155

what are 2 points about cascade reinforcement?

Answer 155

1. selection favouring prezygotic mechanisms which keeps populations from breeding together (decreased gene flow= less unfit hybrids) 2. species 1 and 2 now have area where different mating mechanisms favoured which can cause isolation within species

Question 156

spade foot toads can hybridise what are 3 alternative hypotheses other than reinforcement acting to prevent hybridisation? and what are the 2 species?

Answer 156

1. opportunities for hybridisation declined- no evidence 2. hybridisation initially common when 1 species rare- not true 3. habitat changes reduce hybridisation- no - spea bombifrons: plains spade foot toad - spea multiplicata: New Mexico spade foot toad

Question 157

how may hybridisation be prevented in spade foot toads?

Answer 157

- females of both species usually prefer a fast call rate - s.multiplicata females when in sympatry with s.bombifrons will prefer a lower call rate, changing their mating preference - this is because s.m females suffer more of a decrease in fitness from hybridisation

Question 158

what does evidence of reproductive character displacement on a study in 2014 on spadefoot toads suggest and what else was found?

Answer 158

- reduced gene flow between populations of s.m - suggests reinforcement present - helps to separate populations and reduce gene flow - could kick start speciation within s.m

Question 159

what does reinforcement act to prevent but what does it need?

Answer 159

to prevent gene flow but initially needs some

Question 160

what is the point of maximum reinforcement?

Answer 160

reinforcement can keep pops apart but after a certain point of gene flow- no longer strong enough to keep them apart

Question 161

what is sexual selection and what does it sometimes involve or work in opposition to?

Answer 161

result of differential reproductive success that arises from competition for mates and access to fertilisation - can involve (direct female benefits, good genes hypothesis) or work in opposition to natural selection (fisherman runaway, chaseaway selection)

Question 162

for what 5 reasons is distinction needed for sexual selection and natural selection?

Answer 162

- SS favours mate acquisition and fertilisation, NS favours survival and fecundity - can act in opposition on one trait - have differences in rate, strength, direction with SS stronger and faster and focused on 1 gen - SS may build linkage disequilibrium more effectively - one type may contribute to divergence whilst the other may inhibit it

Question 163

sexual selection can generate prezygotic isolation but what is needed and why?

Answer 163

ecological divergence needed for coexistence

Question 164

what are the 4 ecological interactions with SS?

Answer 164

- food resources - predation - parasitism - sensory bias

Question 165

in terms of food resources what is an example of NS and SS working in the same direction? (7)

Answer 165

North American red crossbills - 10 ecotypes coevolved with conifer species - low gene flow - overlapping ranges - unique call types that differentiate between ecotypes - assortative mating by call type in the wild - experiment: females consistently chose the efficient male feeders by observation - sexual selection is related to feeding efficacy

Question 166

in terms of food resources what is an example of NS and SS working in opposition? (7)

Answer 166

North American swamp sparrow - females prefer high performance songs (those with smaller beak) - bigger frequency bandwidth means more attractive males - trade off between trill rate and frequency bandwidth - recent colonisation of coastal areas has led to larger beaks - different food types in coastal areas so larger beaks develop which produce different songs - not cultural drift, adapting to changing food type - NS moves species to feed and survive but SS aims to increase freq bandwidth

Question 167

what is polygamy dependent on and when is it more likely?

Answer 167

environment | - if clumped more likely

Question 168

whats the difference between the cape penduline tit and the eurasian penduline tit?

Answer 168

cape: monogamous with biparental care and lives in harsh environment eurasian: sexual conflict over investment and no biparental care, each sex tries to escape having to care for nest and often 20% nests abandoned

Question 169

what is an example of how predation interacts with sexual selection and what costs are there on the sexual ornaments?

Answer 169

mortality costs guppy: poecilia reticulata - when high predation adults and babies eaten - low predation just babies eaten - even when no predator still increase in number of spots - increased predation = female preference for less spots - decreased predation = female preference for more spots - no speciation despite rapid co-adaptation of male and female reproductive strategies

Question 170

what are 3 points of how parasitism interacts with sexual selection and give an example

Answer 170

- can exploit host sexual signals - parasite load has effect on host condition (increased load means signal not produced well) - might lead to co-evolutionary cycles that help maintain honesty in sexual signalling - E.g. common yellowthroat: black mask size related to MHC class 2 allele relating to adaptive immunity, allowing females to use this to choose males with better immunity and juvenile males have decreased mask size

Question 171

in terms if the interaction between sensory environment and SS: a) what 3 signals have to navigate an environment? b) in what 3 ways does sound travel and an example of each?

Answer 171

a) visual, acoustic, olfactory b) - absorption: air, vegetation, ground - reflection: trees, buildings - diffraction: temperature gradient

Question 172

how does sound differ between dense foliage and open grassland?

Answer 172

dense foliage: - lower freq - pure tone where 1 note at a time - slower rate of syllable repetition - different frequencies in succession open grassland - higher freq - broadband where several notes at the same time

Question 173

what is the dialect of the madagascan paradise flycatcher?

Answer 173

- different song types favoured in different environments - lower and longer songs in denser foliage - female pref follows what native pop are doing

Question 174

what is the dialect of the brown headed cowbird like?

Answer 174

when females shown different playbacks of male song they would perform for longer during home dialect playback as prefer familiar songs

Question 175

why is speciation and level of SS hard to measure and what pixies can be used?

Answer 175

lack of knowledge - SS: genial size, mating system, dichromatism/dimorphism - Speciation: number of extant species in a clade

Question 176

it is unclear if SS leads to speciation- what may be a reason for yes/example?

Answer 176

birds of paradise - SS more prominent in clades with more species - more clades show asymmetry in diversity in the direction predicted by SS

Question 177

it is unclear if SS leads to speciation- what may be a reason for no/example?

Answer 177

dimorphism and dichromatism and testes size studied and found no difference between clades for high levels of 1 and low of another - no signal of SS in birds explains the variation in species richness

Question 178

even though there are huge imbalances in studies what is the overall effect size as to whether SS contributes to speciation?

Answer 178

postive- does

Question 179

why may the signature of selection fade with time?

Answer 179

likely many speciation and extinction events may have happened that we don't know about

Question 180

why dont we often know which signal to use for working out SS?

Answer 180

some components of SS may have a stronger influence on speciation rate than others (dichromatism has 10X stronger effect)

Question 181

what is 'time for speciation'?

Answer 181

time for reproductive isolation to evolve once process has started

Question 182

what is 'biological speciation interval'?

Answer 182

average time between origin of new species and when that species branches again

Question 183

for each of these what are the TFS estimates? - horses - bivalves - some drosophila - frogs

Answer 183

- 3my - 6-11my - <1my - 1.5my

Question 184

the TFS is unknown for songbirds what has been the deliberation about this?

Answer 184

- hypothesised after glacier retreat birds populated rapidly so a lot of speciation - when looking at sister taxa in 1997 found few speciation events after glacier retreat - 2004 phylogenetic analyses found the opposite with most speciation after

Question 185

what is the TFS example of the African cichlid fish?

Answer 185

- 500 species lake Victoria - lake presumed 750,000 years old - phylogenetic studies predict cichlids 200,000 years old - geological data suggests lake Victoria dried out 14,700 years ago - Verheyen 2003 estimates 98,000-132,700 years ago they moved to rivers and other lakes for refuge

Question 186

what is the area size effect?

Answer 186

the bigger the area the more chance of speciation occurring?

Question 187

what pattern don't ferns follow and so what do they do?

Answer 187

polyploidy common so speciate at random

Question 188

what do high gene flow and high dispersal area need to speciate?

Answer 188

larger minimum area

Question 189

what is the slowest and fastest form of speciation?

Answer 189

mutation or drift | polyploid speciation

Question 190

what is life history and how does it vary and give 7 points as to what it includes

Answer 190

schedule of an organisms life that varies between individuals and species and contributes to overall fitness - age and size at maturity - number and size of offspring - energy allocation to reproduction - timing of growth - dispersal patterns - number of reproductive events - lifespan and ageing

Question 191

what does selection act to maximise? why can't all traits be maximised? what is every trait?

Answer 191

- lifetime reproductive success - reproduction is costly and requires resources and time - continuum with all intermediate states possible

Question 192

what are the 5 life history strategies for a brown rat?

Answer 192

- fast development - rapid maturity - high reproductive rate - low parental investment - short life

Question 193

what are the 6 life history strategies for an elephant?

Answer 193

- slow development - delayed mortality - low reproductive rate - high parental investment - longer pregnancy and high survival of offspring

Question 194

a life history trait involves intrinsic and extrinsic factors, give a) 5 intrinsic b) 2 extrinsic

Answer 194

``` a) - energy/resource constraints - genetic constraints - phylogenetic constraints - mechanical contraints - physiological contraints b) - ecological factors (predation) - climatic constraints ```

Question 195

what is senescence?

Answer 195

age related deterioration of an organism leading to decline in reproduction and probability of survival

Question 196

what kind of life stages is selection most effective for? and list the 3 evolutionary theories as to why

Answer 196

high reproductive rate - mutation accumulation - antagonistic pleiotropy - disposable soma

Question 197

what is the mutation accumulation theory for why selection is most effective for life stages with high reproductive rate ? (5 + example)

Answer 197

- mutations that are deleterious later in life are more likely to be maintained in a population - selection will act against mutations when a high reproductive age - selection doesn't act as strongly later on in life so often more mutations - selection against 1 gene may be more efficient at the reproducing age - genes active later in life can accumulate in the pop - Huntingdon's disease results in death of brain cells and is caused by dominant allele expressed at 30-40 years

Question 198

what is the antagonistic pleiotropy theory for why selection is most effective for life stages with high reproductive rate ? 2+ example

Answer 198

- 1 gene affects more than 1 phenotypic trait - +ve for 1 trait but bad for another (trade off where it may be good now but bad later) - gene may be favoured by selection such as for the gene causing overproduction of sex hormones which is good for reproduction but causes cancer later on in life

Question 199

what is the disposable soma theory for why selection is most effective for life stages with high reproductive rate ?

Answer 199

- resources finite and energy put towards one function is unavailable for others - limits towards maintenance cause somatic damage - if more energy invested into maintenance and growth and less for reproduction the lifespan will be longer

Question 200

why is the mutation accumulation theory not mutually exclusive?

Answer 200

- heritability increases with parent life span (increased mutation, genetic variance and heritability) - age dependent increase in inbreeding (more deleterious alleles, more inbreeding depression)

Question 201

why is the antagonistic pleiotropy theory not mutually exclusive?

Answer 201

- negative correlations between early and late life fitness

Question 202

in the guppies what is the low and high predation situations on the southern side of the mountains?

Answer 202

``` interbreed with high gene flow but distinct differences in life history HIGH: crenicichla - female maturation at smaller size - more smaller offspring - male maturation at smaller size LOW: rivulus - female maturation at larger size - fewer larger offspring - male maturation at larger size ```

Question 203

in the guppies what is the different high predation situation on the northern side of the mountains?

Answer 203

less vicious Gobie and mullet fish - no difference in females - more smaller offspring - males smaller

Question 204

in the guppies what are the high and low predation factors due to?

Answer 204

HIGH: addition of predator- evolutionary changes in guppies in accordance with theory LOW: ecological factors such as predation affecting life history traits

Question 205

when determine how many babies what are the intrinsic factors/trade offs?

Answer 205

- trade off between number and size of offspring - offspring have better chance of surviving if larger and more attention from parent - parents may want more offspring but of smaller size

Question 206

when determine how many babies what are the extrinsic factors example?

Answer 206

songbirds - tropical: smaller clutches, fewer chicks, slower growth rate - temperate: larger clutches, more chicks, faster growth rate

Question 207

explain in detail Thomas Martin's findings from songbirds in 2015 ()

Answer 207

- 3 populations studied: Venezuela and Malaysia for tropical species, Arizona for temperate - peak growth slower in tropical species with same risk of predation as temperate - nesting period shorter in tropics for same growth rate - tropical species have initially slower growth rate but catch up to temperate later in life - mass same at fledging from nest - higher growth rate for wings in tropics (more resources into growing this) - tropical species fledge with longer wings as more predation outside nest so need to get away - wing size can only increase with parental provisioning - total provisioning decreases with nest predation - smaller clutches with fewer chicks to increase provisioning rate - tropical clutch size limited by need to provision for wing growth

Question 208

what did Martin 2015 discover in songbirds for the difference between bigger and smaller clutches?

Answer 208

bigger: adult mortality rates higher but don't develop long wings in nest smaller: increased provisioning in shorter nesting period due to high nest predation

Question 209

do all organisms reproduce and have sex and are there costs?

Answer 209

all reproduce but not all have sex | costs but lack of explanation for existence

Question 210

what is asexual reproduction?

Answer 210

a copying process - some single celled organisms reproduce by mitotic division into 2 daughter cells - some multicellular algae/fungi bud off single cells/spores - easy, error free, simple

Question 211

give 4 points about sexual reproduction

Answer 211

- 2 haploid gametes fuse to form diploid zygote - involves meiosis and recombination and segregation - in many unicellular organisms zygote undergoes meiosis - only half as related to offspring as asexual female

Question 212

what is the paradox of sex?

Answer 212

- inefficient - complicated - time consuming - difficult - dangerous - costly - SS may lead to evolution of costly traits - twofold cost of sex

Question 213

who noticed twofold cost and sex and what is it?

Answer 213

John Maynard smith | - production of males costly

Question 214

what are parthenogenetic females and points about them and a comparison to sexual females

Answer 214

asexual females producing only daughters - 2 fold fitness advantage as sexual females waste half their reproductive potential on sons - multiplying and growing - sexual females have 50/50 chance of daughter and only half as related to offspring as asexual

Question 215

in an ancestral female asexual population what happens when the male mutant arrives?

Answer 215

can't invade pop - males need females to reproduce but females don't need males - if no other benefits to sex then male production should never spread

Question 216

what are 2 assumptions of the twofold cost of sex? and for sex to evolve at least once what is required?

Answer 216

- every female produced equal no.of offspring - no differential survival at least one of the needs to be violated

Question 217

the twofold cost of sex assumes males contribute only genes and so what can help increase the reproductive output of males?

Answer 217

male parental care

Question 218

when can natural selection lead to differential survival?

Answer 218

if there is variation in traits sexual population have genetic variation due recombination, segregation, mutation

Question 219

what can sexual recombination create and destroy?

Answer 219

existing gene combinations whether they are good or bad

Question 220

what do fitness. consequences depend on?

Answer 220

population composition

Question 221

if 2 alleles in the initial pop are favourable what % of unfavourable maladapted offspring will be produced? what would the difference be if these recombinant pairs were more common in the initial pop?

Answer 221

50% | recombinant may have a positive effect

Question 222

what does natural selection favouring or not favouring recombination depend on?

Answer 222

the distribution of genotypes in a population

Question 223

how is it likely that sex can speed up evolution?

Answer 223

as it is unlikely that the same genotype would be created | also recombination can bring together beneficial mutations that arose independently in different organisms

Question 224

what can recombination reveal and what does this improve?

Answer 224

hidden variation | improves response to selection

Question 225

what would happen to a beneficial trait at low level after selection and how may it remain hidden?

Answer 225

can increase in pop but if no sexual variation will remain hidden

Question 226

what are the 2 main models for determining if the short term cost of sex that affects the next gen can be overcome to generate long term benefits?

Answer 226

1. genetic drift (mullers ratchet) | 2. selection in a changing environment (red queen)

Question 227

what can potentially solve problems that mutation and genetic drift create?

Answer 227

sex

Question 228

what is the genetic drift/mullers ratchet model? (7)

Answer 228

- asexual females will pass deleterious mutations to all offspring - the number of deleterious mutations in an asexual lineage can only increase her time - recombination means sexual females may not transfer the deleterious mutation - can recreate mutation free individuals from mutated individuals - optimal genotype lost by drift can be reconstructed by recombination - recombination reduces chances of mutation being passed on - pointed out by Muller 1964

Question 229

what is a piece of evidence for muller ratchet model? (5)

Answer 229

Chao 1990 - generated 20 lines of RNA virus and added drift to speed it up - cultured with single bacterium and incubated and repeated for 40 generations - froze after each generation and placed in competition with next - fitness/growth rate declined after subsequent generations - increased fitness in some hybrid crosses

Question 230

what is an overview of the red queen model/selection in a changing environment?

Answer 230

- sex evolved because recombination brings together novel genotypes with potentially higher fitness which promotes evolutionary adaptation - in unpredictable environments any single genotype may not be universally successful - asexual repeats the same genotypes - sexual creates variation in offspring fitness - different environments have different pressures which creates new gene combinations

Question 231

state the 2 assumptions of the red queen model

Answer 231

- recombination increases rate of adaptation/efficacy of sex | - some novel genotypes have high fitness

Question 232

what was Goddards 2005 experiment demonstrating efficacy of sex? (9)

Answer 232

- demonstrated sexual pops evolve faster than asexual using yeast - yeast usually reproduce asexually if sufficient nutrients but if starved reproduce by meiosis producing 4 spores - 2 genes needed for meiosis melted so reproduction sexual - tested if sex increased variation and promotes evolutionary adaptation - compared growth In harsh and benign conditions - benign: little selection pressure, limited by glucose conc, no fitness increase between the 2 strains - harsh: both strains affected, 94% growth rate increase for sexual strain and 80% for asex - recombination provides advantage in harsh but fitness didn't increase in either strain - shows efficacy of sec not mechanism

Question 233

does the twofold cost of sex apply to yeast?

Answer 233

no as no male female distinction

Question 234

what is the host/parasite example for novel genotypes having high fitness? (4)

Answer 234

- parasites under strong selection to infect - hosts under strong selection to resist infection - continuous shifting of selection as infection and resistance is directed to common genotypes (NFDS) - biotic interactions lead to constant changes in direction of selection

Question 235

what is the lively study on snails example? (4)

Answer 235

- evidence for novel genotypes having high fitness - studied small pops of snails of both sexual and asexual females - +ve correlation between no. of males and level of trematode infection - don't support view that sex is maintained by variable environment but does support that sex is favoured by selection from host parasite interactions

Question 236

what is the morran and lively study on C.elegans? (4)

Answer 236

- evidence for red queen hypothesis where selection from co-evolving pathogens allows the persistence of outcrossing despite costs - experimental coevolution of c.elegans with bacterial pathogen s.marcescens - high levels outcrossing suggests selection of sex - co-evolution could drive asexual populations to extinction or can select for bi-parental care

Question 237

what are 4 brief examples of where investment in traits is costly?

Answer 237

- western grieves: rise out of water and splash which has energetic costs - guppies: bright tails mean more likely to be predated as more visual - red deer: antlers grow new each year which has energetic costs and risk of injury - caw: graduated tail with aerodynamic costs

Question 238

sexual selection can explain traits that go against natural selection and what is an example of this? (8)

Answer 238

body size variation of Galapagos iguanas - snout vent length used as measured of body size to work out selection pressures on this - Santa Fe and genovesa populations - males grew bigger in both - body size not under NS as adult survival doesn't increase with size: survival advantage with body size only until a certain point - larger ones can't obtain sufficient resources to maintain body weight in harsh conditions - males exceeded optimal size for survival but females below - males and females have different body sizes but eat the same resources - male selection pressure is to grow larger if can produce more offspring

Question 239

what is isogamy?

Answer 239

same size gametes- ancestral sexual state

Question 240

what was the first step in the differentiation of sexes ?

Answer 240

origin of mating types as can only mate with those not your mating type

Question 241

what 2 things can evolution of mating types lead to and which is necessary for sexual selection?

Answer 241

1. ever increasing number of types (ciliates have 48 different types) 2. reduction to just 2 types (needed for SS and led to anisogamy)

Question 242

what is anisogamy?

Answer 242

individuals producing different gametes

Question 243

there are many hypotheses proposed for the evolution of anisogamy but which is the one with the most support?

Answer 243

Geoff parkers which is based on disruptive selection

Question 244

what is Geoff parkers theory for the evolution of anisogamy? (4)

Answer 244

- begin with primitive isogamous sexual species with no distinct mating or gamete types - can either produce 1 large or lots of small games if fixed budget - smaller and larger games have reproductive advantage and selection for these is disruptive, giving rise to unequal game sizes - anisogamy results from disruptive selection

Question 245

- what is zygote size? - when does zygote viability increase? - what's the difference between small and larger gametes?

Answer 245

- sum of games that fuse to form it - increases with size - small: produce more and more chance of encountering and fusing with other gametes large: higher resulting fitness of zygote

Question 246

how do males essentially parasitise parental investment of females?

Answer 246

- to increase their reproductive output - male mating success increase linearly with no. of mates - females don't benefit as much from more mates - male mating success more variable than females (Batemans principle)

Question 247

what did Trivers state in 1972?

Answer 247

variance leads to competition between males and choosiness among females

Question 248

what is the male variance in mating success for rough skinned newts? (5)

Answer 248

- clear difference in reproductive success of males and females - most males have few mates and end up with few offspring - reproductive skew with the small number of males having the most matings - females more normal distribution of mates and offspring - males benefit more than females from having multiple partners and gain more offspring for more mates

Question 249

what is the male variance in mating success for broad nosed pipefish?

Answer 249

- sex role reversal - males provide majority of offspring care - females show reproductive skew - females benefit more from increasing number of different mates

Question 250

which investing sex competes for which and which is the most choosy?

Answer 250

sex investing least (often males) competes for sex investing most and the one most is more choosy

Question 251

in what 2 ways has anisogamy resulted in conflict of interest between the sexes?

Answer 251

- competition between males (intersexual) | - female choice of preferred male (inter)

Question 252

state what 2 theories there are for how sexually selected traits initially evolve and what each is

Answer 252

- good genes theory: traits reflect quality of male, trait evolved first followed by preference, high quality males produce high quality traits - sensory exploitation: trait evolves because of female preference, females have pre-existing sensory bias for an ornament and chance mutation in a male produced ornament to match bias

Question 253

what is the auklet example for good genes theory ? (4)

Answer 253

- variation in the genetic quality of males in pop - high quality males produce high quality males with brighter plumage - if females choose. brighter male will produce more fit offspring - ornament and preference will spread through pop

Question 254

what is the auklet example for sensory exploitation? (5)

Answer 254

- introduced least auklet which is the closest related sister species - similar ecology and displays same sexual displays but without crest - stuffed least auklet used to compare attractiveness by putting a crest on the model - significant effect found: more sexual displays performed to models with crests and most displays to longer rather than shorter crest - shows preference evolved before trait so trait originated through sensory exploitation

Question 255

what is the sexually selected trait in the auklet?

Answer 255

feathered ornaments- sexually selected signals with more courtship displays to males with crest and longer crested males more likely to win fight

Question 256

what are direct benefits to choosing?

Answer 256

material benefits that increase for reproductive success of chooser

Question 257

what are indirect benefits to choosing?

Answer 257

good genes that will produce high quality offspring for chooser

Question 258

what is fertility?

Answer 258

ability to produce offspring

Question 259

what is fecundity?

Answer 259

potential number of offspring that could be produced

Question 260

give 3 direct benefits of mate choice?

Answer 260

- fertile or fecund mates - good parenting ability - resources such as food and nest sites

Question 261

what is the female choice of fertile males in lemon tetras? (7)

Answer 261

- both sexes have multiple partners in breeding season - external fertilisation - no parental care - spawns roughly 23 times per day with 7 eggs in each spawn - male fertility declined drastically with successive spawnings - females prefer males that haven't spawned recently - 11/12 tests test females spent more time near non-spawning pair

Question 262

what is male choice of fecund females in pipefish? (4)

Answer 262

- glue eggs to ventral surface of males who care for eggs - females larger and more competitive and develop a skin fold - males prefer females with large bodies and large ventral folds - females with large bodies and large folds produce more eggs

Question 263

what is female choice of male parenting ability in mottled sculpin? ()

Answer 263

- females lay eggs in territories of males - males provide parental care by wafting o2 rich water over them - all male spawning same quality and size - females prefer large males - large males hatch more eggs as can waft more o2 to the eggs

Question 264

explain each example for female choice of resources: - female scorpionflies - male grevys zebra

Answer 264

- swap copulations for nuptial gifts | - males defend waterholes at which females come to drink so mate with the females that come there

Question 265

what is the fallow deer example for female choice of resources? (8)

Answer 265

- rut peaks with acorn fall - females feed on acorns and males protect trees - number of does under tree relates to number of acorns - food was added to the base of some trees and disturbed - control: disturbed but no food added - greater number of females under experimental trees - females fed preferentially in territories with high quality resources - evidence for mate choice resulting in direct benefits but lekking males provide no direct benefits as females only get his genes

Question 266

list 4 models for how sexual selection for indirect benefits is maintained

Answer 266

- fisherman runaway model - chase away model - good genes model - compatibility model

Question 267

what is the fisherman runaway selection model and who came up with it and when?

Answer 267

females that produce males with attractive traits gain indirect benefits as they'll produce attractive sons that will in turn be preferred by choosy females (RA Fisher 1915)

Question 268

what is the bird tail length example for fisherman runaway selection? (4)

Answer 268

1. female arbitrarily chooses long tailed male 2. male offspring have long tail and unexpressed preference for long tail 3. female offspring have preference for long tail and unexpressed long tail 4. tail keeps getting longer until some natural selection cost such as predation limits the trait

Question 269

under fisherman selection what can we predict?

Answer 269

that male traits and female preference should be genetically linked

Question 270

what is the stalk eyed flies example for fisherman runaway selection?

Answer 270

- evidence of linked trait and preference - dramatic sexual dimorphism in eye span, largely as a result of female choice for short eye span - females from long eyespan choose males with long eye spans

Question 271

what is chase away sexual selection, who suggested it and the 2 assumptions of it?

Answer 271

exaggerated male traits evolve through antagonistic coevolution between the sexes (Holland and rice 1998) 1. males producing larger than average ornament which stimulates females through sensory exploitation 2. traits are disadvantageous to female so evolve a resistance to trait 3. male then evolve a more exaggerated trait and females are then attracted to the male again so the trait escalates assumptions: - males seduce females into suboptimal matings - females evolve resistance to such males

Question 272

what is the drosophila example of chaseaway sexual selection?

Answer 272

sperm chemicals inhibit other males sperm and causes female to produce more eggs - harmful to females and can reduce their lifespan - if coevolve male evolves more toxic sperm and females develop resistance

Question 273

what is the good genes model?

Answer 273

- males that could survive despite handicaps must be of high quality - females will mate with high quality males gaining genes that would enable high survival for offspring - under good genes selection wed predict that male traits should reflect the viability of offspring

Question 274

what is the peacock example of good genes model?

Answer 274

- evidence of association between male trait and offspring viability - peahens prefer males with larger eyespots - better offspring that grew faster and survived longer produced when females mated with males with larger eyespots

Question 275

why is it not the case with the good genes model that the population only has males with good genes?

Answer 275

would expect poor genes to be selected out but if only good genes variation would decrease and selection would come to a halt

Question 276

what is the compatibility model?(5)

Answer 276

- individuals choose partners with complementary MHCs (major histocompatibility complex) to them - predicts organisms will prefer partners with dissimilar MHCs - signals are scents/odours - humans both sexes prefer odour of partner with dissimilar MHC - scents that reminded them of relatives found the MHCs closer

Question 277

what is the difference between if an MHCX individual mates with another MHCX rather than MHCZ?

Answer 277

MHCX: would be MHCX offspring so homozygous offspring which has limited disease fighting capability MHCZ: heterozygous offspring with greater disease resistance

Question 278

what did the evolutionary ecologist bill Hamilton state? and also what did he recognise?

Answer 278

one that an organism/himself doesn't stand united in striving to adaptation, the genome doesn't share the same evolutionary optimum as individuals - recognised selection could occur at different levels, between and within individuals

Question 279

what kind go units does a multicellular organism have?

Answer 279

a hierarchy of replicating units - the units satisfy conditions for natural selection and adaptive evolution (variation, reproduction, heredity)

Question 280

give points about the genes on the Y chromosome

Answer 280

- only present in half of male sperm but not in female offspring produced - egg carrels x chromosome so are the homogametic sex - for Y chromosome optima sex allocation is 100% males - selection at chromosome level has a bias sex allocation to males

Question 281

what can genes that drive towards their own optima do?

Answer 281

spread in a pop even if negative effects on carriers fitness

Question 282

- how many types of mitochondria are there - is the cell level or mitochondria level higher - what do the mitochondria do after replication

Answer 282

- 2 types - cell is higher - distributed by segregation at cell division into daughter cells

Question 283

what are the 3 possibilities of two level selection with genomic conflict?

Answer 283

1. if both mitochondria types replicate at the same rate and evenly distributed then there is no natural selection at lower mitochondrial level 2. if the mt types replicate at different rates then the ratio changes from 1 generation to the next and natural selection acts (no conflict if A type benefits more but if a benefits more is conflict) 3. if mt types replicate at same rate but distributed unequally to daughter cells then there is biased segregation favours A at lower level and ratio changes between generations (conflict if mt type favoured at segregation selected against at cell level)

Question 284

what are mitochondrial petite mutations in yeast?(9)

Answer 284

- in bakers yeast small petite colonies can develop on a culture medium - colonies have defective mitochondria, severe metabolic problems and poor growth - yeast cells have many mitochondria with genomes - petite mutations are often large deletions that allow for a faster mutation of mt genome which outcompetes other mt pithing cell - clear case of genomic conflict as mutation is selected for at mt level but against at cell level - successful mutation in short term as mt fixation only at a few cell generations - asexual is the norm for yeast and genomic conflict arises less easily in this system - cells with petite mitochondrial mutation will be selected against as mutation lowers fitness of yeast cells - most suppressive petite mutations show biased segregation when crossed with normal strains

Question 285

what does sex combine and what can it allow for a greater scope of?

Answer 285

- sex combines genomes from different lineages through recombination - allows for greater scope for genomic conflict so more likely a mutation causing genomic conflict will spread

Question 286

what is a petite suppressive mutant example that is transmitted at a higher rate than the rest of the genome?

Answer 286

selfish genetic elements

Question 287

give 4 points about selfish genes

Answer 287

- selfish genetic elements are transmitted at higher rate than rest of genome - detrimental/not advantageous to organism - some genes break rules of mendelian inheritance and overrepresented in offspring (segregation distortion) - they bias bias segregation and drive meiosis away from equality producing <50% gametes with particular allele (meiotic drive)

Question 288

what is sex ratio meiotic drive?

Answer 288

occurs when sex chromosome manipulates sperm production to ensure all functional sperm carry selfish genetic element

Question 289

give 4 points on the sex ratio meiotic drive in drosophila

Answer 289

- drosophila naturally have X chromosome meiotic driver: SR which kills Y bearing sperm of male carriers so only produce x bearing sperm - female biased broods have transmission advantage so SR passed on to all subsequent offspring if mate with carrier male - results in heavily female biased population and eventual pop extinction - SR males only produce half as many sperm so poor sperm competitors

Question 290

what was N.wedell study on D.pseudoobscura?

Answer 290

- study if polyandry can protect against SR in drosophila - hypothesised that polyandry female multiple mating may protect from SR by increasing sperm competition and undermining transmission of frequency driving chromosomes - polyandrous pops had higher prop of males - 5/12 monogamous lines extinct - monogamous line showed higher frequencies of SR than the 3 polyandrous lines - female multiple mating can reduce freq of sex linked meiotic driver

Question 291

what level can selection theoretically act at? but what does it infer?

Answer 291

levels higher than individual organism such as populations and species - but infers group selection which is unpopular with ecologists as groups succumb to selfish individuals

Question 292

did the jurassic forest have pollinators?

Answer 292

no as no pollinators

Question 293

what is the coevolution of insects and flowering plants?

Answer 293

- insects and angiosperms make up large prop of terrestrial species - most arose around early cretaceous

Question 294

what is coevolution? what can it involve? and what 3 things can lead to it ?

Answer 294

- reciprocal genetic change in interacting species owing to natural selection imposed by each other - involves interactions between groups of individuals or genetic elements within species - antagonism, competition, mutualism

Question 295

what is an example of antagonism?

Answer 295

red queen dynamics

Question 296

what is an aspect of evolutionary biology that has a large impact on our daily lives?

Answer 296

parasitism and disease

Question 297

what is the equation for parasite evolution and what does each part stand for?

Answer 297

``` R0= bN/ v + d + r R0: parasite fitness/ no. of new infections bN: rate of new infections b: prob. infecting host N: no. of hosts available v + d + r: rate at which hosts lost v: death by parasite/virulence d: incidental death r: recovery ```

Question 298

what are 2 predictions of the parasite evolution equation?

Answer 298

- correlations between virulence and transmission will increase virulence - vertically transmitted parasites will be less virulent

Question 299

what are 2 examples of what is vertically transmitted?

Answer 299

- mitochondria | - aphids and their symbiotic bacteria (can provide them with nutrients)

Question 300

herbivory is an example of antagonism how is it costly to the plant and what are 3 examples of evolved defences?

Answer 300

- have to regenerate lost parts or will have lost leaf area - thorns/spines - toxins - visual cues such as mimicry

Question 301

what do anti predator defences facilitate?

Answer 301

adaptive radiation by enabling escape from constraints

Question 302

where are the Passion flowers found, how many species and what speeds up and how?

Answer 302

tropics 40 multiple interactions- speeds up rate of speciation

Question 303

what is the escape and radiate defence in amphibians?

Answer 303

chemical defence : temperate regions allow for increased speciation rates - anti-predator defences facilitate adaptive radiation by enabling escape from constraints

Question 304

what are 4 passiflora adaptations and 2 heliconius butterfly adaptations

Answer 304

PASSIFLORA: - vines have toxins/cyanogenic compounds in leaves - egg mimicry - secrete nectar from leaves to attract ants and wasps which feed on caterpillars - leaf shape variation to escape detection HELICONIUS: - caterpillars can detoxify and disable these and use them for their own defence against predators - can learn leaf shapes

Question 305

how was it shown that heliconius can perceive and use leaf shape

Answer 305

- artificial leaves with normal biflora leaf shape and another leaf shape - if trained with biflora would prefer to fly to that leaf shape but if trained on the other would prefer that one

Question 306

for what 3 reasons do plants have egg mimicry?

Answer 306

- female heliconius are picky about where eggs laid - caterpillars of most species are healthiest when fed young shoots which are of limited supply - competition between individuals and species for host plants

Question 307

what 2 things can sometimes happen with competition?

Answer 307

- one species can outcompete another and drive them to extinction - can result in adaptation, reducing competition, helping species co-exist

Question 308

give 3 points about resource partitioning and niche specialisation

Answer 308

- initially 2 species overlap along dimension of niches with a common resource they compete for - over time competing individuals experience less success - natural selection drives species to specialisation and partitioning of resource

Question 309

what kind of competition can you see in heliconius butterflies, why and what are 3 points on the study?

Answer 309

interspecific due to region of sympatry overlap - how species fed on plant when separate and reared together - if species kept together development time is longer - when alone or together display different feeding behaviours

Question 310

what is a plant vs pollinator example of mutualism ?

Answer 310

heliconius - feed on pollen which is unusual as well as nectar so are nutritionally richer so live longer - prefer flowers that are present for the duration of their lifespan

Question 311

what is the psiguria example of mutualism?

Answer 311

- small flowers so flower over a long period | - heliconius can learn where flower is and return to it daily over several months

Question 312

does mutualism mean no conflict? and what is the coffee and citrus plant example?

Answer 312

does not - have caffeine in nectar - alters behaviour of bees to improve their learning and memory and increases re-visitation rate of pollinators - bees will react higher concentrations of caffeine as is slightly toxic to them - flowers keep caffeine levels at right level so bees don't reject the caffeine

Question 313

what are nectar robbers?

Answer 313

bees which can manipulate a flower and drink their nectar directly without pollinating

Question 314

give 3 points about mullerian mimicry

Answer 314

- heliconius species have evolved bright colour patterns to advertise their toxicity to predates - predator will learn the warning colours sooner so individual less likely to be eaten - if several species have same pattern they all benefit by sharing cost of educating predators

Question 315

what has mimetic coevolution been assisted by?

Answer 315

tool kit of major effect genes

Question 316

what has genetic mapping shown in terms of colour pattern variation?

Answer 316

that the same 3 genes produce most of the colour pattern variation even in distantly related species

Question 317

can different traits in the same species co-evolve?

Answer 317

yes in different directions

Question 318

what are 2 major important factors about coevolution?

Answer 318

- abiotic influences produce adaptation - biotic interactions probably more important for diversity such as speciation (competition and co-speciation) and maintenance of diversity (antagonism leading to NFDS)

Question 319

what is fitness an interaction between? and what can selection favour?

Answer 319

genotype and environment with the biotic environment constantly evolving - selection can favour evolvability (evolution of sex and recombination)

Question 320

what are the 3 main ways to study coevolution?

Answer 320

1. models- parasitism 2. observations (phylogenetic coevolution/co-speciation and evolutionary rates, e.g psigura flowers) 3. experiments (e.g. competition between caterpillars, learning of leaf shape)

Question 321

what are 3 examples coevolution below the species level?

Answer 321

- sexually antagonistic co-evolution (SAC) : chase away sexual selection and an arms race between the sexes - co-evolution between genes in the genome (mutualistic being coevolved gene networks which can be seen when hybrid is less fit/inviable) - antagonistic (genome conflict )

Question 322

how is sexually antagonistic co-evolution genomic conflict?

Answer 322

- most differences between the sexes/sexual dimorphism are produced by difference in expression of autosomal genes (sex biased gene expression) - genes that show sex biased expression can have different evolutionary rates likely due to sexually antagonistic coevolution/runaway SS

Question 323

what does group living lead to and what is unlikely?

Answer 323

social interactions | unlikely an interaction mutually beneficial

Question 324

what is the interaction in each case: - actor and recipient benefit - actor does but recipient harmed - actor -ve, recipient +ve - actor -ve, recipient -ve

Answer 324

- cooperative - selfish - altruistic - spiteful

Question 325

what does altruism go against and how can it evolve? theoretically what should happen?

Answer 325

against expected selfish behaviour - if recipient of altruistic act benefits will leave more offspring - the actor/giver is not going to leave more offspring - theoretically should be fewer altruists in next generation and if altruistic behaviours heritable they should ultimately die out

Question 326

what did Williams state and when about group selection?

Answer 326

1966 adaptation benefiting a group rathe than individual don't exist- either is not an adaptation or can be explained by benefit to individual

Question 327

should individual or group selection outdo the other and explain this

Answer 327

individual is the lower level so should out do group - individual organisms more numerous and turnover quicker than populations they're in - potential for replacement of less fit by more fit individuals is greater than that of populations

Question 328

what is kin selection?

Answer 328

altruistic behaviours can evolve by kin selection | - allele can increase in pop if recipient related to individual performing altruistic behaviour

Question 329

what is the alarm calling in belding ground squirrel example for kin selection?

Answer 329

- forage in large groups - females call to alert relatives of danger - only females remain on natal territory so are highly related to other squirrels in population

Question 330

what is the bird helpers at the nest example for kin selection?

Answer 330

- helpers tend to be related to parents and are often offspring from previous broods - parents with more helpers have more chicks - helpers failed at their own breeding attempts - usually males, as operational sex ratios skewed to males s they have more resources to use for helping - males can stay and help for up to 6 years

Question 331

who selected kin selection and why and what is the rule?

Answer 331

Hamilton - to explain problem of altruism, incorporating the idea of inclusive fitness rB - C >0 rB > C r= degree of relatedness/how many identical genes by dense you have B= benefit to recipient C= cost to actor

Question 332

a) what what Hamiltons equation for inclusive fitness? b) what does amount of indirect fitness depend on? c) what happens when you increase the amount of indirect fitness?

Answer 332

a) inclusive fitness = direct fitness/personal fitness gains + indirect fitness (additional fitness from relatives) b) how related individuals are to each other c) increases inclusive fitness

Question 333

in hamiltons rule what happens when C increases and when B or r increases?

Answer 333

C: direct fitness increases | B or r: indirect fitness increases

Question 334

what is the probability of a daughter who has a brother, sharing alleles through... - mum - dad - mum and dad

Answer 334

- 0.5 X 0.5 = 0.25 (mother X brother) - same as above - 0.5

Question 335

what is the probability of sharing alleles with a nephew through... - mum - dad - joint

Answer 335

- 0.5 X 0.5 X 0.5 =0.125 (mum X brother X dad) - same as above - 0.125 + 0.125 = 0.25

Question 336

what are 3 characteristics of eusociality as the ultimate in reproductive altruism and an example?

Answer 336

1. overlap in generations between parents and offspring 2. cooperative brood care 3. specialises castes of non reproductive individuals e. g.: insects such as termites, Hymenoptera: ants, wasps, bees, also naked mole rats

Question 337

what is the haplodiploid in Hymenoptera?

Answer 337

- males haploid - females diploid - haplodiploidy changes r - sisters share 100% fathers genes and 50% mothers genes so: (0.5 + 1)/2 = 0.75 - females more closely related to each other (0.75) than to brothers (r=0.25) and their own offspring (r=0.5)

Question 338

how can females increase inclusive fitness?

Answer 338

by being sterile workers, helping to produce reproductive sisters

Question 339

is haplodiploidy the explanation of eusociality in Hymenoptera?

Answer 339

1. 0.5 relatedness assumes only 1 male fertilises a queen but not true in honeybees where the queen has multiple mates but may reduce r 2. in some species colonies are founded by more than 1 queen 3. many eusocial non-hymenoptera are diploid such as termites 4. many Hymenoptera aren't eusocial - haplodiploidy may facilitate eusociality evolution but more important factor may be need of help rearing young

Question 340

eusociality may have 3 independent origins what are these associated with and give examples of eusociality in groups

Answer 340

nest building and need to supply larvae with food | - spheroid wasp, honeybees, ants, paper wasps

Question 341

what kind of species does eusociality only occur in?

Answer 341

those with complex nests and extensive larval care

Question 342

why did eusociality likely evolve?

Answer 342

due to ecological selection pressures rather than underlying genetic system

Question 343

what is kin selected discrimination in cannabalistic spade foot toad tadpoles

Answer 343

- tadpoles develop into typical morphs eating mostly decaying plant matter - when conditions change develop into carnivores that eat other tadpoles - if given choice to eat sibling cannibal morphs will eat non siblings which is consistent wit the kin selection theory

Question 344

what is sperm heteromorphism?

Answer 344

in some species males produce different distinct morphologies of sperm with 1 morph fertile and the other sterile

Question 345

is the infertile morph being altruistic to the fertile morph in drosophila pseudoobuscura?

Answer 345

- female reproductive tract spermicidal - non fertile parasperm protects brother fertile eusperm from female spermicide which is harmful - the effect is increase with ratio of parasperm to eusperm - proves sperm to be altruistic

Question 346

what is the intraspecific conflict in mouse sperm

Answer 346

- have hooks to latch onto female reproductive tract and to each other - if sperm competition sperm avoid joining with sperm conspecifics and only join to sperm from the same male rather than a brother - evidence of sperm cooperation where sperm can discriminate based on genetic relatedness

Question 347

what is the kamikaze sperm hypothesis?

Answer 347

sperm type that sacrificed its own chances of fertilisation to neutralise the sperm of competing ejaculates - block, incapacitate and kill rival sperm

Question 348

active kin directed behaviour requires kin recognition how is this achieved?

Answer 348

- smell (mammals and insects) - song (some birds) - learned familiarity (raised together) - visual similarity (chimps, humans)

Question 349

is kin recognition required for kin selection to operate?

Answer 349

no- kin selection will operate as long as altruists are biased towards kin so selection will favour this behaviour

Question 350

how many species does the open tree of life aim to represent?

Answer 350

2.3 million species

Question 351

what did J.B.S Haldane notice ?

Answer 351

inordinate fondness for beetles

Question 352

how much does species richness vary across clades of tree of life?

Answer 352

a great deal animals most species rich kingdom arthropods most species rich animals - pattern of diversity unevenness common throughout tree of life

Question 353

what is phylogenetic tree imbalance?

Answer 353

relative numbers of descendent tips on branches that originate at focal node - if unequal numbers each side of node is imbalance

Question 354

what are 3 points on the equal rate Markov model?

Answer 354

- species arise from other species | - probability of speciation and extinction per unit time is constant across lineages

Question 355

what can trees be unbalanced by?

Answer 355

chance | - more likely than balanced and more common than expected under null model

Question 356

is there variation in clade age for species richness variation?

Answer 356

clade age and species richness are uncorrelated across 1,397 clades of multicellular eukaryotes - no relationship

Question 357

what is net diversification rate?

Answer 357

net rate of lineage splitting | = lineage birth rate/speciation - lineage death rate/extinction

Question 358

when measuring using a lineage through time plot LTT- when is clade growth exponential and what does this look like if logged

Answer 358

if speciation rate constant and extinction zero | - straight line if logged

Question 359

in Hawaiian silverswords roughly how many species are produced per lineage per million years

Answer 359

0.6

Question 360

what is the relationship like in kingdoms and other levels between diversification and species richness

Answer 360

strong

Question 361

how many clades account for what % of vertebrate diversity?

Answer 361

5 clades- 85%

Question 362

what is a strong predator of species richness at any taxonomic level across tree of life?

Answer 362

net diversification rate

Question 363

what are 3 factors that may influence diversification rate

Answer 363

species traits and environmental factors

Question 364

in terms of diversification rates how can speciation and extinction be separated

Answer 364

- if probability of extinction and speciation constant through time then as we approach the present number of extinctions will decline - extinction can be calculated by comparing the recent slope with the past slope

Question 365

give points about the trait dependent diversification in nightshades

Answer 365

- large family of flowering plants - important commercial crops (potato, tomato, pepper, capsicum medicine, petunias, tobacco) - 2700 species - 98% hermaphrodites - 57% self compatible - 41% self incompatible

Question 366

what is self incompatibility and what does a loss of it allow?

Answer 366

ability of hermaphrodites to enforce outcrossing and avoids inbreeding depression - loss enables self fertilisation

Question 367

- in what kind of lineages are speciation and extinction rates higher - in which is net diversification higher - in which is net diversification negative

Answer 367

- Self compatible - SI - SC

Question 368

diversification rates differ among SI and SC lineages how is this distribution maintained?

Answer 368

balancing short term advantages of SC with long term advantages of SI

Question 369

for what 2 main reasons is heterozygote advantage not common?

Answer 369

1. imposes load on the pop (difference between max and mean fitness) 2. unstable due to duplication/mutation where disadvantageous allele may be duplicated and fixed at different location so passed onto next generation after recombination (such as globin family of genes)

Question 370

why is it harder for hitchhiking alleles to occur in mammals?

Answer 370

sexually reproducing so recombination more frequent

Question 371

what is jones et al 2013 example for hitchhiking alleles in mammals

Answer 371

humans for lactose digestive allele

Question 372

what is balancing selection?

Answer 372

when selection acts to maintain different morphs in a population