Topic 3

Question 1

Charles Darwin’s Theory of evolution by natural selection.

Answer 1

1. More offspring produced each generation, then can be supported by the environment.
2. Heritable variations in traits among individuals in populations.
3. Some traits will give an individual a better chance of surviving and reproducing and other individuals without those traits. (higher fitness.)
4. advantageous trades become more common in the population over subsequent generations.

Darwin travelled on a ship beagle, —>noticed species on different islands were similar, but had traits that helped them to survive on their specific islands, —>studying the connection between the environment and evolution, helped Darwin develop his theory. —> evolutionarily ecologists also study healthy environment, influences evolution

Evolution is a change in a population over time or a change in gene frequencies overtime

Question 2

Genome vs gene

Answer 2

Genome: All of the genetic material an individual has

It is divide it up into chromosomes

Gene: specific pattern of the genome for example, it could be a code for a particular protein behaviour or traits . Different variations of genes or called alleles.

Question 3

Mendel

Answer 3

Offspring resemble parents, because the parents pass on the traits.

Question 4

Genotype vs phenotype

Answer 4

Genotype: is the genetic make up of an organism (the genes they have)

Phenotype: the characteristic that they have as a result of the interaction between their genotype and the environment (genotype x environmen).

• Genotype can determine phenotype
  A good question to think about is how much the trait is influenced by the environment or their genetics .

This type of question is good for conservation. We can be able to help change the environment or make sure a gene is not erased from the population.

Question 5

Genetic variation

Answer 5

How much genetic variation there is in a population

Take Individual GenoTypes, and try to summarize them.

Populations could share many alleles.

Question 6

Phenotypic variation

Answer 6

How much phenotypic variation There is in a population.

What portion does the population have of a specific allele?

This is important because it’s what natural selection acts on therefore consequences of survival based on what an organism looks like.

Question 7

Chuckwallahs (Sauromalus ater)

Answer 7

Large herbivorous desert lizards of SW U.S and Mexico

• case (1976) explored how elevation influences body size via natural selection in 12 populations

Question 8

Phenotypic variation in desert lizards activity questions

Answer 8

What does the graph tell you about the relationship between winter rainfall and elevation??
— positive correlation —> increase elevation = increase precipitation

What does the graph tell you about the relationship between variation in winter rainfall and elevation?
— negative correlation —> increase elevation = decrease Variation or increase elevation = decrease rainfall
— constant environmental that’s is different, then other environment
— large, the impacts, the type of animals and plants able to survive

What is fact might this have on food availability? (Chuckwallahs eat plants)
— higher elevation = more consistent predictable and available food source
— higher elevation = more plants available at higher elevations
— food availability is a way to measure biodiversity

How might this affect the body size (phenotype) shaped through natural selection?
— higher elevations = larger body size

How could you phrase this as a hypothesis/prediction?

— so wondering how does elevation affect the body plan? How does food play a part in this?

— [if there’s grader and more predictable food at higher elevations] <— hypothesis, [then body size phenotype will increase with elevation] <— prediction

Is this due to food availability in a given year or to genetic differences that have evolved among populations, how would you test this?
Briefly, describe an experiment you could do to pass this question.

— for environment you change the food type they have and keep them at the same elevation, and if their body plan changes that means it’s environmentally influenced, but if it is not, the downside is that you are not counting, for if elevation is impacting.

— genetic testing with wild animals isn’t always good because not a lot of information is always known about that species

— you could put them in the same conditions, and this is known as a common garden experiment

What pattern would you expect to see if the trait is only determined by genetics?

— the lizards were all have the same size they would’ve had in their original environment —> you see a difference (Variation) in juveniles raised.

|
you would see some differences in size, but not as extreme as the original environment would cause
|
V
— the lizards would all grow to the same size/body length —> no variation in body size.

Question 9

Common garden experiment

Answer 9

This is where you, take individuals from different environments and raise them in the same environment.

This will allow you to determine its characteristics, or phenotypic traits are a result of environmental, influences or genetic influences.

Ex: heights of yarrow plants grown in a common garden experiment, shows that there is still variation indicating the height is genetically influenced. However, the images do not show us a picture of the heights of the yarrow plants in their original environment, this means we don’t know the extent of variation in their height, and if it is completely genetic, or a combination of genetics and environmental influences.