MYATT Flashcards
Define animal behaviour
Explains the mechanisms and the function of a behaviour and the evolution of biological diversity
Define behavioural ecology
How the physical environment impacts on an animal’s behaviour and its evolution
Define sociobilogy
How an animal’s social environment affects their behaviour and evolution
What is behaviour
What an animal does - Raven and Johnson, 1989
The coordinated response of whole living organisms to internal and/or external stimuli - Dugtakin 2014
What are the 4 key questions when looking at animal behaviour
- Mechanistic - how and what
- Survival value - reproduction, fitness level, role in survival
- Developmental - how is behaviour developed, learned or innate?
- Evolutionary/ phylogenetic - how has this behaviour enabled evolution and been able to pass on genes
Darwin’s theory of natural selection
- Variation: individuals differ in morphology, physiology and behaviour
- Competition: scarce resources
- Success/ fitness consequences: those with advantageous characteristics will survive and pass on to offspring
- Inheritance: some variation is heritable, offspring normally represent their parents more than other individuals
- Adaptation: over time and generations a species becomes more adapted to its environment
Innate behaviour
- genetically programmed response to an external stimulus
- subject to change through mutation, recombination and natural selection
- heritable: passed on in genes
- intrinsic: happens even if raised in isolation
-stereotypic: behaves and does same thing in same way every time - inflexible
- consummate - occurs at max capacity first time expressed
Fixed-action patters (FAP) - sequence of unlearned behavioural acts
- causes a chain reaction e.g. bee wiggle
- unique stimulus
- unchanging
- once initiated, carrie out to completion
- behavioural cascades can occur
- supernormal stimulus: exaggerated signal to produce a more vigorous response
Learned behaviour
- persistent change in behaviour that occurs as a result of experience
- can be individual and social but occurs within the lifetime of an individual
- non-heritbale
- extrinsic (will not happen if raised alone)
- permutable - can change over lifetime
- adaptable - can adapt to different environments
- progressive - you can get better
Types of learned behaviour
Habituation: getting used to a stimulus, can ignore it
Observational learning: learning by watching
Conditional learning: learning via reward or punishment
Learn through play: trying out different things by self or others
Insight learning: relies on fact that you can learn from previous experience so you can adapt and change behaviour
Imprinting
- programmed learning: innate behaviours are released in response to a learnt stimulus
- critical sensitive period
- establishes a preference or avoidance - follow mother or avoid siblings
- stress increases strength of imprinting
What is social leaning
Transfer of information from individual to individual though social learning within and between generations
- individual learning disappears when that individual dies
- cultural transmission faster than natural selection changing frequency of genes that code for a behaviour
Evolution of learning
- assume cost to learning
- ability to learn is a trait with an underlying genetic basis
- ability to learn favoured in environments that changed relatively often as otherwise will become innate
- no change: fixed genetic rule
- constant change: fixed genetic rule
Evolution of group living
- all behaviours have selfish aspect
- altruism and cooperation - helping another individual at a fitness cost to yourself
- fitness (success) = ability to survive and reproduce
can be achieved by - having own offspring (direct fitness)
- helping relatives to raise their offspring (indirect fitness)
- kin selection: backbone of many cooperative and altruistic behaviours
Hamilton’s rule (1964)
- solved paradox of altruism
rB>C
r= coefficient of relatedness (more likely to help sibling than cousin)
B= benefit gained by recipient
C= cost to individual performing act
r is the % of genes shared by common descent between 2 individuals
parents and child r=0.5
full siblings r=0.5
grandparents, uncles/ aunts, cousins r=0.25
Pathways to groups
- increasing direct fitness - leads to more fluid groups of non-related individuals
- increasing indirect fitness - offspring remain to help parents raise next generations due to ecological constraints
- delayed individual breeding success - pay-to-stay; help raise non-kin, gain experience and resources, wait until ecological conditions are right
Advantages and disadvantages of group living
Advantages:
- breeding
- foraging
- energetic savings
- anti-predation
- anti-parasite defence
- transmission of information
Disadvantages:
- exploitation
- predation
- disease transmission
- risk to young
- competition
- in-breeding
What is sexual selection
Intrasexual selection: members of one sex compete with each other for access too the other sex e.g. male to male fight
Intersexual selection: individuals of one sex choose which members of the other sex to mate with e.g. female choice
Stems from fact that females produce few, large gametes whereas males produce many, small gametes; males can fertilise eggs faster than they are produced
Bateman’s principle
Reproductive variance is greater in males than females
Females invest more energy into their gametes, have fewer in number thus can be choosier
Males are fundamentally promiscuous, females selective
Males can develop traits that enable them to be more successful
The goal of sexual selection is to explain the existence of such traits, the mechanism by which they are favoured and their variation among species
What are secondary sexual characteristics
- features not directly part of reproductive system that develop during sexual maturity
- often results in sexual dimorphism
- aim is to give an individual a selective advantage
- direct e.g. weapons and size
- indirect e.g. ornaments (peacock)
What is sperm competition
Defensive tactics
- mate-guarding: consortship in primates
- mating/ copulatory plugs: gelatinous secretion that hardens in the female genital tract
- toxic seminal substances: accessory gland proteins, anti-aphrodisiac (she wont want to mate with anyone else) and induce ovulation
Offensive
- physical removal of sperm
What is cuckoldry
- males who unwittingly invest parental effort into offspring that are not their own
Different morphs in fish
Parental - stay with a female and help look after eggs
Sneaker - fly through after females have laid eggs, fertilise eggs themselves then leave
Satellite - sneaker male has become too big, make themselves look female so they can get close to fertilise eggs
Morphs developed as way to compete with other males
All result in success and so persist via sexual selection
What is female choice
- invest more in initial gamete production, but even more if there is internal gestation but also beyond
- females have more to lose therefore need to make their choices carefully
What are the different evolutionary models
Direct benefits
- additional resource benefits
- access to food
- shelter/ protection
- parental care
- nuptial gifts
Good genes
- good genes code for more favourable traits
- males would prefer to cheat - give impression they have good genes
- sexual selection pressure on females will lead them to use honest indicators (traits that cant be cheated)
Runaway sexual selection
- evolution of exaggerated male ornamentation
- peacock tail: paradox of natural selection
positive feedback loop; when a female mates with colourful mate -> colourful offspring that prefer colourful mates
Sensory exploitation
- preference for a male trait emerges because it elicits a neurobiological response in females that initially is not related to mating preference e.g. red in primates
What is polyandry
- female ensures reproductive success
- one female, many males
- rare in mammals and birds, frequent in insects and reptiles
- e.g. marmosets; dominant female suppress ovulation in subordinates, normally give brith to twins every 6 months
