The evolutionary basis of behaviour L3 part 1

Question 1

What are the Elements of the natural selection theory?

Answer 1

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.

Question 2

Given an example of natural selection

Answer 2

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.

Question 3

Explain Darwins research into Beak shapes

Answer 3

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.

Question 4

What is a chromosome?

Answer 4

Long DNA molecule

Question 5

What is a Gene?

Answer 5

Gene: (Located at the locus) Codes for a protein sequence of nucleotide bases.

Question 6

Explain Diploid

Answer 6

Animals which have 2 copies of each chromosome are known as Diploid.

Question 7

Explain Haploid

Answer 7

But Gametes (Egg, sperm) have only one copy, therefore haploid due to meiosis. They become two when other Gametes are met.

Question 8

Explain Alleles

Answer 8

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

Question 9

What is the difference between Dominant and Recessive?

Answer 9

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)

Question 10

What is Mendelian variation?

Answer 10

New combinations of alleles from parents

Question 11

What are gene mutations?

Answer 11

Occur at random- generally deleterious (less likely to survive) a few will be beneficial and selected for…
Chromosome mutation-

Question 12

What is Chromosome mutation?

Answer 12

Chromosome mutation- Crossing over - chromosome breaks during meiosis and rejoins in a different arrangement.

Question 13

What is genetic drift?

Answer 13

Genetic drift: random shifts in allele frequencies (Caused by a small gene pool).

Question 14

What would alleles that have an effect on the reproductive success cause?

Answer 14

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.

Question 15

Give two examples of allele affects on allele frequency

Answer 15

Selection to improve survival chances, for example feeding, avoiding predators.

Selection to improve reproduction chances, for example sexual selection based on Antler size.

Question 16

How is behavior under genetic control?

Answer 16

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.

Question 17

Give an example of genetic behaviour

Answer 17

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.

Question 18

What is Epigenetics?

Answer 18

Where the life experiences of one generation can affect the behaviour of the next (Heriatable).

Question 19

How are most behaviors controlled?

Answer 19

Most behaviour is controlled by a large number of genes and /or environmental factions.

Question 20

Name Dog-like features associated with domestication of foxes

Answer 20

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.

Question 21

Explain Darwinian fitness

Answer 21

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

Question 22

How do you apply fitness to individual genes

Answer 22

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

Question 23

Explain inclusive fitness

Answer 23

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

Question 24

Explain maximizing fitness

Answer 24

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.

Question 25

Explain Optimal foraging models with the examples

Answer 25

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

Question 26

Explain Evolutionary stable strategies

Answer 26

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.