Unit 1: Evolution - Natural Selection

Question 1

When did Darwin return to England?

Answer 1

In 1936

Question 2

What did Darwin do when he returned to England

Answer 2

Wrote papers describing his collections & observations

Question 3

What did Darwin bring back?

Answer 3

Brought back thousands of specimens and fossils

Question 4

What came out in 1844?

Answer 4

A draft of his theory of species formation

Question 5

What was Darwin concerned about?

Answer 5

The impact of his ideas in a religious culture

Question 6

What did Darwin instruct his wife to do?

Answer 6

Instructed his wife to publish this essay upon his death

Question 7

What was Darwin reluctant to do?

Answer 7

To publish but didn’t want ideas to die with him

Question 8

What happened in 1858?

Answer 8

Darwin received a letter that changed everything.

Question 9

Who was the letter from?

Answer 9

Alfred Russel Wallace, a young naturalist working in the East Indies

Question 10

What had Alfred Russel Wallace done?

Answer 10

Had written a short paper with a new idea.

Question 11

What had he asked Darwin?

Answer 11

To evaluate his ideas and pass it along for publication.

Question 12

What happened on November 24, 1859?

Answer 12

Darwin published “On the Origin of Species by Means of Natural Selection”

Question 13

What was Darwin’s first idea?

Answer 13

Variation exists in natural populations

Question 14

What was Darwin’s second idea?

Answer 14

Many more offspring are born each season than can possibly survive to maturity

Question 15

What was Darwin’s third idea?

Answer 15

As a result, there is a struggle for existence - competition

Question 16

What was Darwin’s fourth idea?

Answer 16

Characteristics that are beneficial in the struggle
for existence will tend to become more common in the population, changing the average characteristics of the population - adaptations

Question 17

What was Darwin’s fifth idea?

Answer 17

Over long periods of time, and given a steady input of new variation into a population, these processes lead to the emergence of new species

Question 18

What was Darwin’s first observation (Darwin’s Theory of Evolution by Natural Selection)?

Answer 18

Individuals within a species vary in many ways

Question 19

What was Darwin’s second observation (Darwin’s Theory of Evolution by Natural Selection)?

Answer 19

Some variability can be inherited

Question 20

What was Darwin’s third observation (Darwin’s Theory of Evolution by Natural Selection)?

Answer 20

Each generation produces way more offspring than can survive and passes on variations

Question 21

What was Darwin’s fourth observation (Darwin’s Theory of Evolution by Natural Selection)?

Answer 21

Populations tend to remain stable in size

Question 22

What was Darwin’s first inference (Darwin’s Theory of Evolution by Natural Selection)?

Answer 22

Members of the same species compete with each other for survival

Question 23

What was Darwin’s second inference (Darwin’s Theory of Evolution by Natural Selection)?

Answer 23

Individuals with more favourable variation are more likely to survive. SURVIVAL IS NOT RANDOM

Question 24

What was Darwin’s third inference (Darwin’s Theory of Evolution by Natural Selection)?

Answer 24

Survivors contribute proportionately more offspring to succeeding generations the favourable variation will become more common THIS IS NATURAL SELECTION

Question 25

Why did people not believe Darwin's theory?

Answer 25

Not everyone thought the earth was millions of years old

Question 26

What did fossil records have?

Answer 26

HUGE gaps (geology and palaeontology are new sciences)

Question 27

What did fossil records now show?

Answer 27

Transitional forms

Question 28

What did people not know about?

Answer 28

Genetics

Question 29

What has life on earth been dated at?

Answer 29

3.5 billion years

Question 30

Today, how many more fossils have been found?

Answer 30

Far more fossils found which show progression

Question 31

What do we understand today?

Answer 31

Genetics, mutations, and recombination - this gives the most compelling evidence

Question 32

What happened in 1866?

Answer 32

Gregor Mendel publishes work on peas (ignored until 1900s)

Question 33

What came from the idea of Natural Selection?

Answer 33

Two results or theories (to further study)

Question 34

What are these two results or theories called?

Answer 34

Descent with Modification Common Descent

Question 35

What is Descent with Modification?

Answer 35

Each living organism has descended, with changes from other species over time

Question 36

What is Common Descent?

Answer 36

Were derived from common ancestors

Question 37

What is Natural Selection?

Answer 37

A mechanism of evolution where by traits become more or less common in a population due to effects on survival and reproduction

Question 38

What are the four types of natural selection?

Answer 38

1.Directional Selection 2.Stabilizing Selection 3.Disruptive Selection 4.Sexual Selection

Question 39

What is directional selection?

Answer 39

Selection that favours an increase or decrease in the value of a trait from the current population; favours the phenotypes at one extreme over another.

Question 40

What is stabilizing selection?

Answer 40

Selection that favours intermediate phenotypes and acts against extreme variants

Question 41

What is one example of stabilizing selection?

Answer 41

Human babies have an average size Too big and they can't get through birth canal Too small and they have low survivability

Question 42

What is disruptive selection?

Answer 42

Selection that favours two or more variations of a trait that differ from the current population average

Question 43

What can disruptive selection lead to?

Answer 43

New species forming

Question 44

What is mimicry?

Answer 44

Similarity of one species to another which provides protection

Question 45

What are some mimicry similarities?

Answer 45

Appearance, behaviour, sound, scent

Question 46

What is sexual selection?

Answer 46

Differential reproductive success caused by variation in the ability to obtain mates

Question 47

What does sexual selection result in?

Answer 47

Results in sexual dimorphism, and mating courtship behaviours

Question 48

What is sexual dimorphism?

Answer 48

A phenotypic difference between males and females of the same species

Question 49

What phenotypic differences result from sexual dimorphism?

Answer 49

Morphology Ornamentation Behaviour

Question 50

What is one example of sexual selection?

Answer 50

Female Mate Choice: Females choose mates based on physical traits, such as bright colouration and behaviour

Question 51

What is another example of sexual selection?

Answer 51

Male-versus-male competition = males have physical features that assist them in establishing control of and defending their territory used in direct competition

Question 52

What are some changes in the genetic makeup of a population NOT?

Answer 52

Influenced by the traits of individuals

Question 53

What are examples of evolutionary change without selection?

Answer 53

1.Genetic Drift 2.Bottlenecks and Founder Effect

Question 54

What is Genetic Drift?

Answer 54

Changes to allele frequency as a result of chance are much more pronounced in small populations

Question 55

What happens when populations are small?

Answer 55

Chance can play a significant role in altering allele frequencies.

Question 56

What is a genetic bottleneck?

Answer 56

A dramatic, often temporary, reduction in population size, usually resulting in significant genetic drift

Question 57

What is the founder effect?

Answer 57

Genetic drift that results when a small number of individuals separate from their original population and establish a new population

Question 58

What is a human example of the founder effect?

Answer 58

Polydactyly (extra fingers and toes, a symptom of Ellis-van Creveld syndrome) are more common in Amish communities in the US

Question 59

Why is Polydactyly more common in Amish communities in the US

Answer 59

This is because they have grown from a very few founders, have not recruited newcomers, and tend to marry within the community