Examples

Question 1

An example of a phenotype

Answer 1

How tall a giraffe is
How fast a plant grows
If a rat is agresiva or take

Question 2

Where does genetic variation come from

Answer 2

Mutations and recombination (meiosis)

Question 3

Where does phenotype come from?

Answer 3

Genotypes variation and environmental variation

Question 4

Frequencies

Answer 4

All frequencies have to add up to 1

Question 5

There is a new mutation what will happen next?

Answer 5

It depends:
• If the new variation increases or decreases : natural selection
• If the population is big or small : genetic drift
• if the individuals in the population are mating randomly or not : non random mating

Question 6

Once there is variation in a population, what can change how common it is?
Hint: natural forces

Answer 6

• natural and sexual selection
• genetic drift
• gene flow
• non random mating (inbreeding)

Question 7

If a genetic variant decreases fitness, we expect this variant to?

Answer 7

Become less common through time

Question 8

If a genetic variant increases variant, we expect this variant to ?

Answer 8

Become more common through time

Question 9

3 conditions of natural selection:

Answer 9

• variation in population
• variation leads to higher fitness
• variation is heritable

Question 10

Sexual selection

Answer 10

Some individuals have more access to mates than others. This leads to higher fitness

Question 11

Important hint of genetic drift

Answer 11

Occurs when populations are small

Question 12

Explanation of genetic drift

Answer 12

Because the population is small some variants (by chance) don’t get passed from one generation to the next. It becomes less variable as one allele becomes more common

Question 13

Genetic drift is random

Answer 13

What allele becomes most common is random

If two populations are evolving due to genetic drift, they will become less similar

Question 14

What are chance events?

Answer 14

Anything that reduces the size of a population:
• bottleneck
• founder effect
• geographic barriers

Question 15

Example of bottleneck

Answer 15

A natural disaster

Human hunting

Question 16

An example of founder effect

Answer 16

A few individuals from a population colonize a new island and start life there

A few individuals from a population colonize a new part of the world

Question 17

An example of geographic barriers

Answer 17

The highways that split up all the populations of animals into smaller populations

Question 18

Gene flow populations

Answer 18

Each population becomes more variable

The two populations exchange Individuals become more similar

Question 19

Example of gene flow

Answer 19

Florida panther was experiencing genetic drift so humans brought Texas panthers to mate with them. It increased the variation in the Florida cats

Question 20

Explantation of non random mating

Answer 20

Inbreeding is an extreme example

It tends to decrease variation with in a population

Question 21

Examples of non random mating

Answer 21

Royal families liked to inbreed to keep the wealth in the family
There are lizards that reproduce with themselves. The species only consists of females

Question 22

What are the main two ways to determine if a gene or trait is evolving ?

Answer 22

Visually see if the frequency of the allele/ phenotype is changing through time, of it is, its evolving

Use the hardy Weinberg equilibrium

Question 23

The hardy Weinberg only applies when

Answer 23

The population is NOT evolving

Question 24

How to use the hardy Weinberg equilibrium

Answer 24

1. Get the data on REAL genotypic frequency
2. Calculate allele frequency
3. Use the equation to calculate expected genotypic frequencies
4. Compare real to expected data
5. If they are similar, it’s not evolving
   If it’s different, it’s evolving

Question 25

Each sex differs in how much energy they invest into reproduction in

Answer 25

Makes tend to not be involved in parental care which is why they spend more energy in being showy

While females tend to spend most of their energy in making and caring for their offspring which is why they’re picky

Question 26

Examples of fecundity

Answer 26

The number of babies a male can have is limited by the mates they can find

Most females in a population have about the same number of offspring

Question 27

Reproductive success examples

Answer 27

Females have less variable reproductive success and tend to be picky when choosing a mate

Males have very variable reproductive success and tend to be more showy

Question 28

Example of Intrasexual selection

hint within a population

Answer 28

When males compete with other males to get access to females
Or
When females compete with other females to get access to males

Question 29

Example of intersexual selection

Answer 29

When females pick a male to mate with or when males pick a female to mate with

Question 30

Why should an individual be picky about who they choose to mate with?

Answer 30

The mate might provide you with direct benefits, good genes, or sexy sons

Question 31

An example of direct benefits

Answer 31

A male could help raise the offspring, give resources like food or territory

Question 32

An example of good genes

Answer 32

If a mate has good genes that will help the offspring to survive by inheriting the trait

Question 33

Example of sexy sons

Answer 33

Is when a mate has a trait that the female likes and when they mate their offspring males inherit the trait and the females inherit the liking of the trait. This helps the chances of the offspring finding a mate

Question 34

An example of runaway selection

Answer 34

It can be bad

The elk became instinct because of its large antlers and they would get stuck in the trees.

Question 35

Types of natural selection

Answer 35

Directional- one extreme trait has the highest fitness
Stabilizing- being at either extreme results in lower fitness
Disruptive- being at either extreme results in high fitness, being in the middle is no good

Question 36

Three hypotheses why an individual might be picky

Answer 36

Direct benefits
Good genes
Sexy sons