Lecture 1 - Evolutionary approach

Question 1

what are the two basic questions a biologist can ask about animal biology and who came up with them?

Answer 1

• How do they do it; what is the mechanism?
• Why? (what is the benefit of doing it in terms of transmitting your genes to the next generation?)
• Tinbergen

Question 2

what does proximate mean and what 2 things help explain it?

Answer 2

• how do they do it
• causation (mechanism behind it)
• development (ontogeny)

Question 3

what does ultimate mean and what 2 things help explain it?

Answer 3

• why do they do it
• evolution (phylogeny - history of an organism )
• function (selection - why was it selected for?)

Question 4

describe level of analysis in animal behaviour?

Answer 4

‘Level of analysis’ refers to whether you’re studying ultimate or proximate causes, and which aspect of these are you studying - two hypotheses aren’t competing they are asking different questions about the same behaviour at different levels

Question 5

give examples of proximate causes in the 2 levels of analysis: causation and development

Answer 5

1) sensory- motor mechanisms e.g. - nervous systems for the detection of environmental stimuli or hormone systems for adjusting responsiveness to environmental stimuli or skeletal-muscular systems for carrying out responses
2) genetic - developmental mechanisms e.g. - effects of heredity on behaviour or development of sensory-motor systems via gene-environment interactions

Question 6

give examples of ultimate causes in the 2 levels of analysis: evolution and function

Answer 6

1) historical pathways leading to a current behavioural trait e.g. events occurring over evolution from the origin of the trait to the present
2) selective processes shaping the history of a behavioural trait e.g. past and current usefulness of the behaviour in promoting lifetime reproductive success

Question 7

red squirrels hide food sources in cashs for periods of low food availability - describe the proximate and ultimate mechanisms to explain this behaviour?

Answer 7

proximate:
cause - in autumn there is an overabundance of food stimulating them to hide food
development - instinct leads them to hide the nuts and learning helps them to find good hiding spots
Ultimate:
evolution - ancestors of red squirrels gathered nuts into a pile - winter food source
function - individuals which store nuts are more likely to survive the winter and reproduce

Question 8

describe the route of explaining a behaviour?

Answer 8

1) look at developmental systems such as the gene products, gene-environment interactions and genetic makeup of the individual
2) look at the physiological systems caused by a sensory input e.g. motor systems, sensory systems and hormone systems
3) gene transmission (fitness)
4) gene pool of next generation

Question 9

describe tinbergens experiment for testing a proximate hypothesis

Answer 9

orientation in bee wolves - female bee wolf feeds her underground nest with honey bees - she covers the nest before going hunting - she circles the nest before hunting- want to test the proximate hypothesis why does she do this? - she does this to memorise landmarks near the entrance of her nest
- tinbergen tested this by moving landmarks and the bees then couldn’t find the nest

Question 10

describe tinbergens experiment for testing a ultimate hypothesis

Answer 10

he wanted to understand WHY birds remove broken egg shells after birds have hatched? tinbergen hypothesised that the bright white inside of a shell would make the nest very visible to predators therfore removing the shells would incur a survival advantage - this was proven in experiment where the closer the broken shells were to the nest the greater the predation

Question 11

what are the 4 steps of scientific method?

Answer 11

1. Ask a question about an observed behaviour
2. Establish a hypothesis to potentially explain what has been seen
3. Set up predictions based on the hypothesis
4. Test these predictions by gathering appropriate data (field observations, experiments etc.)

Question 12

what can behavioural traits help you infer?

Answer 12

the evolutionary history (phylogeny) of families i.e. the origins of some characteristics
e.g. if 3 out of 4 subfamilies demonstrate eusociality ( a high level of social organisation) it is likely the origin of eusociality occurred after the other subfamily had evolved making that subfamily the most derived