Alternate bio220 quizlet 2

Proximate Cause

how & what, relationship in genetics and behaviour

Ultimate Cause

why, behavioural evolution

Phenotypes

Z \= G + E + G x E

Phenotype Genetic Impact

gene single nucleotide mutation (foraging gene)

- Rover (A-) or Sitter (aa) alleles

Phenotype Environmental Impact

expression dependent on environment (food deprivation)

- outside 24hrs, Rovers act like Sitters

Phenotypic Plasticity

environmentally induced variation in the phenotype

- adaptive (high plasticity)
- not adaptive (low plasticity)

Reaction Norm (single genotype)

low genetic effect + high environmental effect \= high plasticity

high genetic effect + low environmental effect \= low plasticity

Sexual Selection

sexual selected traits increase the availability and quality of mates

- strength selection equals mating success

Measuring Sexual Selection

does the trait correlate to the quality and quantity of offspring

Sexual Dimorphism

gender-exclusive traits, unique in same species

- size, armaments, ornaments

Intrasexual Competition

same sex competition (males)

Intersexual Competition

mate competition (females)

Operational Sex Ratio

the ratio of male to female individuals who are available to reproduce

male or female biased

Gamete Expenditure

Males: sperm inexpensive, access to gametes limits fitness

Females: eggs expensive, access to ressources to produce gametes limits fitness

Parental Investment Theory

members that invest little in reproduction compete to mate with those who invest more

Pre-Copulation Factors

number copulations

- Fighting Behaviour
- Social Status
- Territoriality

Post-Copulation Factors

number successful copulations

- Mate Guarding
- Copulation Duration
- Sperm Removal
- Sperm Plugs
- Anti-Aphrodisiacs

Mate Choice

trait in one sex that biases mating choice in the other sex

- Visual Cues (e.g. Widowbirds choose elongated tails)
- Acoustic Cues (e.g. Tungara Frog chooses complex calls)
- Tactile Cues
- Olfactory Cues

Puzzle Choice

mates select elaborate traits

Direct Trait Selection

on individuals making choice

- select traits promoting access to ressources

Indirect Trait Selection

on offspring of individuals making choice

- select mates with high genetic quality, promote fitness

example: Bluegill Sunfish

mate with Parental Males (direct) or Satellite & Sneaker Males (indirect)

Environmental Investment

mate availability is resource dependent

Food Abundant (environmental investment)

more males mating, less competition and choice

Food Limited (environmental investment)

less males mating, more competition and choice

Cooperation

adopted behaviour in two individuals that provides shared benefits at no cost

Shared Direct Benefits

cooperation is advantageous

Hawk-Dove Game Theory (shared direct)

strategies dependent on Resources and Costs

frequency-dependent equilibrium

Reciprocity

disadvantageous not to cooperate provided repeated interactions

Predation Prisoner's Dilemma (reciprocity)

group cooperation promotes best group outcome

Altruism

behaviour that increases other individuals fitness at cost to personal fitness

Kin Selection

selection for genetic relative, increased gene fitness

- Random Individuals: non-Altruist favoured, freq. decreases

- Genetic Relatives: Altruist favoured, freq. increases

Hamilton's Rule (kin selection)

B (altruism benefit to recipient) x R (genetic relatedness)
\> C (altruism cost to actor)

Offspring

demand resources

benefit: individual fitness

costs: number future siblings

Parents

supply resources

benefit: offspring

costs: number future offspring

example: Stitchbirds

Carotenoid-Supplements Stitchbirds demonstrate increased resource provisioning and reproduction.

Parent-Parent Interaction

single parent care, other parent deserts

consider Costs (quality offspring) and Benefits (quantity offspring) of deserting

example: Kentish Plover

male care

- low benefit to deserting, increased re-mating time
- high costs to deserting, low offspring survival

'Things' Produced by Individuals

genotype promotes behaviour that produces some thing

thing as a marker for fitness (e.g. Beaver Dam Building)

'Things' Produced in Individuals

behaviour promotes activity in individuals that increases fitness (e.g. Provisioning)

Parasite Transmission

R0 \= \# disease transmission generated from single individual

dependent on growth and replication opportunities

Extended Phenotypes

facilitate the growth, reproduction, and transmission of host to increase parasite fitness

promotes natural selection for trait

- Adaptive for Parasite
- Adaptive for Host
- Coincidental By-Product

example: Malaria

Oocytes (not infectious) develop to Sporozoite (infectious)

Oocyte Stage (malaria)

decreaed bloodmeal-sucking, increased survivorship

Sporozoite Stage (malaria)

increased bloodmeal-sucking, increased transmission

Malaria Hosts

draw more mosquitoes, increased attractiveness

- healthy-hosts that smell like disease selected
- disease-hosts that smell like hosts not selected

Evolutionary Medicine

application evolutionary principles to problems in health and disease

Vulnerability to Disease

1) Trade-Offs
2) Pathogen Evolution
3) Natural Selection increases Reproductive Success of Genes
4) Disease is actually Defense
5) Mismatch with Current Environment

4. Disease is actually Defense

quantify costs and benefits of trait to both individuals and pathogens

Fever (4)

elevated body temperature response

Direct Consequence Pathogen Replication (inc. success)
or
Adaptive Defense to Pathogen (dec. success)

example: Desert Iguana

behavioural thermal regulation, elevate body temperature in response

inc. temperature (40C) \= dec. pathogen growth rate, inc. immune response mechanisms

example: Humans

fever symptoms worsened with Anti-Fever treatment, immune response suppressed

Fever as evolved defence mechanism

5. Mismatch with Current Environment

humans adapted to environment that is not what we live in right now, environments similar to our ancestors

example: Myopia

elongated retina, phenotypically plastic

- modern environments more susceptible
- more frequent in new generations

gene responsible did not produce in past environments (GxE)

Aging

progressive decline in soma, non-adaptive

reduction in fertility and survivorship

Proximate Theory of Aging

oxidative metabolism causes cellular damage, accumulates

produces accelerated aging

Reproductive Theory of Aging

increased reproductive rates associated with decreased longevity

Evolutionary Aging Theories

trait selection strength declines with age

Reproductive Value

\= expected gene contributions to future generations at age 'x'

Late Life Deleterious Genes have high reproductive value earlier in life, more likely to pass on genes

Early Life Deleterious Genes have low reproductive value earlier in life, less likely to pass on genes

Mutation Accumulation

Late Life Deleterious Genes accumulate in genome through evolutionary time.

- more likely to express genes at early and reproductive age
- less likely to express genes at later age

Example: Huntington's Disease

late onset promotes gene transmission

Antagonistic Pleiotropy

genes with Beneficial Effects early in life are favoured, despite Negative Effects later in life

- more likely to experience benefit at early age
- less likely to experience costs at later age

example: T Allele

reduces susceptibility to Early Onset Glioma Cancer

increased susceptibility to Diabetes

Selection Lines

old-age reproducers develop increased Late Age Fecundity and Longevity, decreased Early Age Fecundity

Predation and Reproductive Time

likely decrease in longevity pushes animals to reproduce earlier to be able to transmit genes

Parasite Control: Killing Parasite

drug treatment promotes parasite resistance

genetic variation in parasite sensitivity

Parasite Resistance Fitness Advantage

more resources

less competition

Parasite Control: Killing Vector

eradicating parasite hosts

freq. resistant allele inc. in treated area, dec. in untreated area

Antibiotics

kill and block bacteria growth

Antibiotic Resistance

resistance develops at rapid rate

- increased drug administration
- variable resistance

Antibiotic Evolution

high replication rates produce new mutations

Horizontal Gene Transfer (HGT)

resistance gene transported in bacteria cells in DNA Plasmid Loops, duplicates

- Commensal or Pathogenic, environmentally dependent
- non-target antibiotic use increases freq. resistant genes

example: HIV

- insert into Host CD4 Helper T Cells, reverse transcriptase
- insert HIV DNA into Host DNA, transcribe viral DNA
- new virus spreads

example: AZT-Triphosphate

inhibits Reverse Transcriptase, prevents additional nucleotide binding

binds and inactivates HIV Enzyme

example: AZT-Triphosphate Resistance

Mutant HIV Enzyme resistant to AZT-Triphosphate.

Active Site recognizes AZT, does not bind.

Antibiotic Resistance Solutions

1. Bigger Doses (more resistance??)

2. Earlier Treatment // pre-exposure

3. Drug Combinations // combat multiple mutations

Virulence

degree of pathogenicity

additional mortality that a pathogen promotes

Conventional Wisdom (virulence)

claim: pathogens that hurt host hurt themselves

prediction:

-high virulent, recent host-pathogen relationship

- low virulent, existing host-pathogen relationship

Challenges to Conventional Wisdom (virulence)

Tuberculosis still highly virulent

Myxoma Virus virulence stabilized at moderate level

Trade-Off Hypothesis

balancing disease transmission (benefits) and disease virulence (costs)

maximize replication

Virulence Evolutional Model

R0 \= T(r) x D(r)

T(r): new infections / day
D(r): days infection lasts

Methods Transmission

1. Direct Host-Host Transmission

2. Vector Transmission

Direct Host-Host Transmission

mobile host

low replication and virulence

high frequency

Vector Transmission

host not mobile

high replication and virulence

moderate frequency

Virulence Evolution

low replication benefits \> costs

moderate replication benefits \= costs

high replication benefits < costs

Multiple Genotype Parasites

single genotype receive benefits

all genotypes share costs

- compete for resources, transmit more (virulent*)

Relative Transmission

the transmission of one parasite strain compared to other parasite strains

Flu Biology

HA Hemaggluting

NA Neuraminidase

HA Hemaggluting

principle antigen

NA Neuraminidase

pathogen spread, movement out

Zoonotic Flu

viruses occurring naturally in wild animals

no human immunities, no vaccine available

example: Bird Flu

H5N1 strand

Tokyo, bird host

weak human-human transmission

Zoonotic Flu Evolution

viral evolution to be better at transmitting in humans

Pandemic Flu

novel human viruses

minimal natural immunity, easier transmission

example: Spanish Flu

H1N1 strand

Spain WW1

soldiers mobilization and spread

Pandemic Flu Evolution

viral evolution to avoid the effects of immunity

Seasonal Flu

viruses circulate in human populations

possible human immunity, available vaccines

Flu Evolution

a. Antigenic Drift

b. Antigenic Shift

Antigenic Drift

small mutations accumulate, change Antigens

Antigenic Shift

major recombination gene segments and antigens

req. 2 viruses (animal, human) to infect cell, produce new virus