The evolutionary basis of behaviour L3 part 1 Flashcards
What are the Elements of the natural selection theory?
Variation among individuals in a population is found
Most variation is heritable
Resources are found to be limited
Offspring are produced in greater numbers than can typically survive.
There is competition for resources
Better competitors or better adapted animals, produce more offspring, which makes their gene more common in the next generation.
Given an example of natural selection
Peppered moth (Biston betularia)
They have two types of natural camouflage, light or black morph.
200 years ago the light morph was more dominant than the black morph which was rare.
However due to the industrial revolution, lichen died off, therefore soot formed on trees
There trees became almost entirely black, meaning black Peppered moths could camouflage into the trees.
Since then black Peppered moths increased in numbers and white Peppered moths became rare.
And experiment was done to prove this, showing more black moths were taken from white trees, then white moths. Also on black trees more white moths were taken by predators then black moths.
Explain Darwins research into Beak shapes
Darwin’s research into finches showed that the shape of a finches beak was adapted to the different diets depending on its location on the island and diet resources surrounding it.
What is a chromosome?
Long DNA molecule
What is a Gene?
Gene: (Located at the locus) Codes for a protein sequence of nucleotide bases.
Explain Diploid
Animals which have 2 copies of each chromosome are known as Diploid.
Explain Haploid
But Gametes (Egg, sperm) have only one copy, therefore haploid due to meiosis. They become two when other Gametes are met.
Explain Alleles
Many genes occur as 2 or more alleles alternative versions of a gene (variation)
each code for a slightly different version of same protein
Each organism has an allele from mother and from father.
2 identical alleles = Homozygous
2 different alleles = Heterozygous
What is the difference between Dominant and Recessive?
Dominant = Allele which controls the characteristics whenever it is present. (BB = Homozygous and Bb = Heterozygous.)
Recessive = Allele where characteristics only show up when it is present on both chromosomes. (bb = Homozygous)
What is Mendelian variation?
New combinations of alleles from parents
What are gene mutations?
Occur at random- generally deleterious (less likely to survive) a few will be beneficial and selected for…
Chromosome mutation-
What is Chromosome mutation?
Chromosome mutation- Crossing over - chromosome breaks during meiosis and rejoins in a different arrangement.
What is genetic drift?
Genetic drift: random shifts in allele frequencies (Caused by a small gene pool).
What would alleles that have an effect on the reproductive success cause?
If the different alleles have different effects on the reproductive success of their owners, this will therefore cause changes in the allele frequencies in the population gene pools.
Give two examples of allele affects on allele frequency
Selection to improve survival chances, for example feeding, avoiding predators.
Selection to improve reproduction chances, for example sexual selection based on Antler size.
How is behavior under genetic control?
There is variation among individuals in a population
Much of this variation is heritable
Some behaviours governed by small number of genes and show mendelian inheritance.
Give an example of genetic behaviour
Hygienic behaviour means the bees remove the dead larvae from cells
Unhygienic behaviour therefore means the dead larvae are left the decompose leading to possible disease. It is seen that different populations have different behaviours.
If the two different Allele types are crossed they all end up as unhygienic (Therefore unhygienic is dominant).
Trait on 2 independent genes
One for uncapping cells u (Do uncap) or U (Don’t uncap)
One for removing larva r (Do remove) or R (Don’t remove)
Parents UURR X uurr = F1 generation UuRr (Heterozygous), this is the only possible Genotype of the offspring.
Mechanism appears to be olfactory (Sense of smell) senses.
What is Epigenetics?
Where the life experiences of one generation can affect the behaviour of the next (Heriatable).
How are most behaviors controlled?
Most behaviour is controlled by a large number of genes and /or environmental factions.
Name Dog-like features associated with domestication of foxes
Wagging tails
Floppy ears (Originally constantly rigged)
Black and white colouration
Roll over to be patted
Lick humans’ hands
Look directly into eyes of humans (usually avoid eye contact)
More object play- Juvenile traits.
Explain Darwinian fitness
Darwinian fitness: “A measure of an individual’s capacity to produce offspring”.
Fitness depends on
Ability to survive to a reproductive age
Mating success
Fecundity of mating pair
Survival of offspring to reproductive age
How do you apply fitness to individual genes
Survival of particular gene in the gene pool from one generation to the next
Natural selection is the differential survival of alternative alleles
The selfish gene Dawkins
Explain inclusive fitness
Relatives share many genes with an individual (Siblings on average share half their genes).
So helping relatives is another way of insuring your genes make it to the next generation. (Eg sterile termites, Some termites don’t reproduce or can’t but will protect relatives and help with upbringing)
An animal’s fitness depends on:
Its own reproductive success
And that of its kin
Every aspect of an individual’s behaviour will make a difference to its fitness
Difficult to measure the effect of anyone behaviour on overall fitness
Explain maximizing fitness
Animals should seek to maximise number of offspring that survive
Optimal behaviour
Seek to optimise:
Chances of their own survival and that of offspring
Maximise benefits and minimise costs of activities- Cost benefit analysis.
Resolves competing demands, eg between feeding and avoiding predators.
Explain Optimal foraging models with the examples
Maximum energy in, for minimum energy out
Example of model of oystercatchers: Should eat largest mussles however…
Some very large mussels can’t be opened at all
Some large mussels covered in barnacles
Actual best size is smaller 30-45mm
In real life more complicated, other factors
Need to take other animals into acount
Explain Evolutionary stable strategies
The optimal behaviour of individuals depends on what other animals are doing, for example competitors and predators.
An evolutionarily stable strategy is one that if adopted by most members of the population cannot be bettered by any other strategy
Can study this using Game theory. Example: Hawks and Doves fighting strategy mode.
