Lecture 1- Behaviour (How and why), Evolution (How it works), Tinbergen's four questions, Research methods and How do animals make decisions. Flashcards
Approach to study animal behaviour:
What approach will we be adopting?
What is it?
Will we also be looking at the adaptationist perspective?
Behavioural ecology approach.
It is a modern approach to the study of animal behaviour from an evolutionary perspective.
Yes- this is the ways in which animals behave (adaptations).
Behaviour- How versus why:
What are the two types of questions we can ask about behaviour?
Explain an animals scientific name.
Give an example using animals.
Give another example.
In this module, what can you do with names?
How and why questions.
The scientific name is two words. The first is the genus and the second is the species.
Like an alpine marmot is called marmota marmota. The first part is the genus, the second part is the species.
Homo (genus) sapiens (species). This is humans.
You can refer to the scientific name or the common name as long as you are specific (can be with the way it looks) like saying black rats.
What is behaviour?
Essentially, what?
How can you look at behaviour?
Explain.
How animals interact with other organisms and the physical environment.
Essentially, everything you see animals doing.
Can look at behaviour at different levels. There are simple behaviours like moving a limb or you can look at how these simple things are integrated together into something like running or more specific like running away from a predator.
What do diggerbees do?
Does he defend his digging spot if needed?
What kind of questions can you ask about behaviour?
Explain the how part for diggerbees.
They dig to find females to mate with. After he will stroke her so she is not responsive to other males (courtship).
Yes.
How and why questions;
How does a male bee know where to dig?
Why do males in this species engage in this behaviour (rather than wait for females to emerge)?
How- find out using a dead female bee- essentially, you would bury her and see whether they find her through odour or sound- the answer is odour (because a dead female bee will smell like one but not sound like one).
How questions:
What are these?
Give examples.
Explain some examples further.
Proximate mechanisms.
E.g. anatomical, physiological, biochemical, neural and hormonal etc.
Anatomical- What bit of the brain is involved?
Neural- What neurons are involved in causing something to happen?
Hormonal- What hormones trigger a behaviour?
Why questions:
What are these?
Give examples.
Is this asking questions about how the behaviour evolved?
Ultimate causations- what is the function of a behaviour?
Maybe because they are competing for reproductive opportunities (mating opportunities).
Yes.
Give an example of something an animal does and how you can explain this behaviour through proximate and ultimate causations.
Behaviour- tiger rubbing its head against a tree.
Proximate causation- Feels good- Rubbing its neck could stimulate a sensory neuron connected to the pleasure centre in the brain which creates a reward feeling that makes the tiger want to keep doing it.
Ultimate causation- Marks territory- Scent is located in the neck- The tiger is leaving its scent all over the tree in order to mark its territory.
In order to answer questions about ultimate causations, what do you need to refer to?
Why?
Is this a scientific framework to account for why organisms appear to be adapted (designed) to survive and reproduce in their particular environment?
Can you also look at the developments of this theory which have occurred since then?
Are there other types of selection? Give an example.
Darwin’s theory of evolution by natural selection.
It helps us understand why animals behave in the way they do.
Yes.
Yes.
There are other types of selection such as sexual selection.
PT 2- Evolution- Natural selection:
What are the three essential ingredients for natural selection (for evolution to occur)?
Explain them all.
When darwin came up with the theory, did he know what a gene was?
1) Variation- Organisms vary in many ways.
2) Inheritance- Some of this variation can be passed onto offspring- Different versions of genes are called alleles.
3) Selection- Organisms with heritable variants leave more offspring because this variation means that some individuals have attributes which allow them to survive and reproduce more effectively.
No- he just knew organisms varied and some variation can be passed on.
What is a genotype?
What is a phenotype?
Does genotype influence the phenotype?
What can one thing cause another?
Look at slide 51 for this to be explained better (read the bottom as well).
Genotype- collection of genes that makes them up- their blueprint.
Phenotype- physical characteristics and how it behaves.
Yes.
Differences in genotype can cause differences in phenotype.
Natural selection in action:
Give an example.
Is there variation here?
There was a drought in the Galapagos island which reduced the number of small seeds available to finches- This caused many small beak finches to die (can only break into small seeds to eat, not bigger ones)- There was an increase in finches average beak size in the years following.
Yes- when selection (drought) happened, those with a variation were more successful (heritable).
What is the trait that evolution produces called?
What is an adaptation?
Why did it evolve?
Does it have a genetic basis?
Does it regularly develops in members of the same species?
Can behavioural traits also be seen as adaptations?
Adaptations.
Characteristic that has arisen through and been shaped by natural and/or sexual selection. Part of the design of the species.
It helps to solve problems of survival and reproduction in the evolutionary ancestry of the organism.
Yes.
Yes.
Yes.
Say the equation for evolution.
Do adaptations have evolved functions?
What do they increase?
What is fitness (Darwinian fitness)?
What is it simply about?
Does fitness also depend on the success of close (genetically similar) kin?
Variation + Inheritance + Selection (natural or sexual) = Adaptations (therefore evolution happened).
Yes.
Survival and/or reproductive success (i.e. fitness).
When traits evolve because they increase survival and/or reproductive success.
It is simply about successful survival and reproduction.
Yes.
What is a sophisticated definition of fitness (Darwinian fitness)?
How does evolution work?
Explain.
Is natural selection trying to achieve anything?
What can selection not do?
Does evolution happen in gradual steps?
Genetic contribution
Evolution generates lots of variation and the stuff that works best is kept and the stuff that does not gets lost (does not leave much descendants). Its aim was not there to solve a problem. It is a blind process.
No.
Selection cannot anticipate future needs, it can only act on existing variation.
Yes.
Does adaptations evolve for the good of the species?
What kind of traits does selection favour?
Could it favour traits which are bad for species?
No.
Traits which enhance the ability of individuals to survive and reproduce (i.e. leave more descendants than competitors).
Yes- e.g. being a super efficient predator- will wipe out the prey population.
Why do some species look similar (or behave in similar ways):
What can this be down to?
What is convergent evolution?
When does convergent evolution occur?
Does it lead to evolution of similar traits?
Convergent evolution or homologous traits.
It is when species that are not closely related evolve similar traits (look and behave alike) that solve similar problems.
It occurs when different species are exposed to similar selection pressures.
Yes.
Continuation from convergent evolution:
Give an example of convergent evolution in animals.
Are hippos and crocodiles closely related?
What issue did they have and what was the solution?
Example is that hippos and crocodiles both have their eyes above the water (on top of their head) but keep their bodies underwater.
No- Crocodiles are not mammals whilst hippos are.
They had the issue of how do I look around if my body is under water. The solution was to have eyes on the top of your head, they evolved these solutions separately.
Homologous traits:
What is this?
What are homologous traits similar in?
Explain.
Give an example.
Species may possess similar traits because they inherited them from a recent common ancestor, are closely related (NOT due to convergent evolution).
Homologous traits are similar in structure and/or genetic basis, but may have very different functions and appearances.
Example- Think about the four limbs of a mammal (human) and the wings of a bird.
