Evolutionary Approach

Evolutionary Approach

1. Why study animal behaviour; long history in psychology, to understand the mind, interesting, applications e.g. biological control, animal training, understand how evolution shapes behaviour, common principles that guide behaviour, insight into human behaviour.

2. Evolution; Definition- change over time of allele frequencies in a population, other forms of change; morphology, speciation, extinction.

3. Darwin's theory; evolutionary change through natural selection. Continual competition between individuals in a population for resources and some individuals contribute more offspring to the next generation than others. Provides that offspring resemble parents (i.e. that physical and behavioural traits ate heritable), the traits of individuals that lead more offspring than average will increase frequency overtime (the contribution of an individual to the gene pool in the next generations is its evolutionary fitness). this produces evolutionary change.

4. Inheritance; Lamarckism- inheritance of acquired characteristics, Mechanism of inheritance; genes.

5. Sources of variation; genetic mutation- recombination. The central dogma; DNA makes RNA makes protein. Variation not subject to evolution.

6. Fitness; survival of the fittest (Herbert Spencer 1864), the currency of selection, consists of survival and reproduction (and enduring that your offspring reproduce) fitness variation are preserved through time; morphology and behaviour

7. Adaptation; process by which organisms improve their fitness, also refers to the trait that improves fitness, natural selection produces design, without a designer.

8. Misconceptions about evolution; evolution is just a theory; a is gravity, extremely well supported by evidence from very wide ranging sources, one species evolves into another, evidence has foresight.

9. Evidence for evolution; fossils, comparison of organism ( embryology, physiology, genetics), geographical distributions of life, modern, observed examples.

10. Contrasting ideas on why humans are social; human primarily selfish, solitary and aggressive but enter int social contact to curb their naturally selfish instincts. group living benefits individuals so that behaviours which facilitate group living are favoured.

11. Levels of selection; Wynne- Edwards; animal dispersion in related to social behaviour, Animals modify their behaviour for the good of there group (the gloved fist); population density. Individuals; George Williams; adaptation and natural selection, Imagine a selfish individual who takes more than his share of resources, outcomes a rest of the group and produces more selfish offspring, group become selfish. in practise, conditions are not likely to favour group of over individual selection, genes? Genes are the 'immortal coils', whereas bodies are impermanent. is the body and genes way of making more genes.

12. similarities between organisms; living things can be similar to each other for 2 reasons: Homology; similarity due to common ancestor. Analogy; similarity due to other factors.

    • Homology; come from a common ancestor, homologies are everywhere, not always immediately obvious.
    • Analogies; similarities, body shape, live in water, hunt fish, dorsal fins and flippers. not derived from commne ancestor but evolved separately due to convergent evolution.
    • Homology and analogy in psychology; related species with similar skills- probably homology, no divergent evolution. Unrelated series with similar skills- probably analogy, via the process of convergent evolution.

13. Explaining behaviour; different ways to explain a behaviour or cognitive ability, why do raven console victims of aggression; it alleviates distress in an ally, it strengthens bond important for survival, ravens evolved a social system based on close social bonds and competition, they learnt the behaviour from their parents, gave other ravens clear signals for affiliation, a simple S-R learnt mechanism.

14. Evolutionary theory, understanding behaviour. Tinbergen 4 why'd 1963, Niko Tinbergen 'father' of theology (obversataonal study of animal behaviour). there are 4 different meanings to the word why when applied to behaviour, 4 possible levels of explanation. Function; ultimate reasons, evolutionary fitness. Phylogenetic (when?); evolutionary history. Ontogenetic (how?); nature vs nurture, developmental. Proximate (what?); mechanics, hormones, nervous system, triggers.

15. Tinbergens 4 questions- Function (why?); what is he adaptive significance of the cognitive ability/ behaviour? what is the impact of the ability on the animals fitness? Evolution (when?); what selection pressures let to the evolution of this ability? how might this ability have evolved. Developmental (how); what experiences during an individuals life time produce this ability? how does it change with age. Mechanisms (what); what are the internal and external factors that vies rise to this ability? Environmental/ social/ psychological/ biology, neurological etc. function and mechanism go hand in hand.

16. Approaches to animal behaviour. we cannot ask animals about their cognitive abilities so need to find ways to gain insight into their minds. observation, experiment, comparisons across species or groups, living or extinct, mathematical modelling.

17. 1. Function answers; why do these cognitive abilities occur? what is the adaptive significance of an ability? determine what the behaviour is good for? compare individuals to see if those with the ability are more successful. playbacks can be useful ways to understand function. e.g. the function of vocal discrimination in elephants (McComb et al. 2001)

18. 2.Evolutionary answers; when and why did the cognitive abilities evolve. cognitive phylogenies; cognitive ability in related species, compare cognitive abilities in unrelated species. Both methods investigate the social, ecological factors (niches) that give rise to a particular cognitive adaption; through fossil records, more difficult with behaviour.

19. 3. Ontogenetic answers; How did these cognitive abilities develop in an animal life time; compare different upbringings, how plastic is this ability, nature vs nurture balance the role of development and evolution, document developmental stages. Example domesticated hypothesis, hand reared dogs vs wolves, home reared dogs vs shelter dogs.

20. 4. Mechanistic answer; what are the immediate causes of these abilities. can refer to the environment, psychological, biological, neurological. e.g. different levels of cognitive complexity, e.g. neurological mechanisms of reward; dogs trained to remain motionless moved their heads less than 1mm. showed reward and non reward commands (Berns et al. 2012). specific brain areas associated with reward were identified. FMRI may revolutionised comparative psychology as it has human psychology

21. Case study; Birdsong, why do male birds sing. Proximate; male song birds sing but females don't, genetic differences, Hormones-testosterone, Genetics (foxP2), environment cues- Daylight. Ontogenetic; white crowded sparrow dialects. Phylogenetic; how widespread is learned birdsong, 3 out of 23 again orders, when/ how did birdsong evolve?. Function; territorial defence from males, attracting females, female preferences- song complexity linked to nutrition and condition.

22. Human evolutionary psychology; what insights can it provide into human behaviour. outdates view; animals are rigidly controlled by their biology, human behaviour is determined by culture. challenged by what we know about nominal behaviour, ignores our shared evolutionary history, ignores the biological basis of many human traits and the cultural basis of some animal traits.