Lecture 2

Question 1

Humans do not evolve….. what does

Answer 1

Populations

Question 2

What can amplify or diminish only heritable traits

Answer 2

Natural selection

Question 3

An individuals acquired traits can or cannot be passed onto its offspring?

Answer 3

Cannot

Question 4

Will traits that maximize an individuals survival become more come? Why?

Answer 4

It can be detrimental to an individual but can be selected for if relatives carry the genes for the behaviour

Question 5

Are humans the pinnacle of evolution? Why?

Answer 5

No, evolution hasn’t directed the production of species to some endpoint, evolution will continue

Question 6

Did humans evolve from closely related primates?

Answer 6

Living things evolved from a common ancestor but not from eachother

Question 7

Does the theory of evolution explain the beginning of life on earth?

Answer 7

Evolution by natural selection explains changes in life on earth but the idea of how life actually started is still in the hypothesis stages

Question 8

How did complex structures evolve

Answer 8

By incremental change ( in increments, not all at once)

Question 9

How come there are gaps in the fossil record?

Answer 9

Some transitional fossils are not preserved

Question 10

Why does natural selection involve tradeoffs

Answer 10

An adaptation for one life process may conflict with another

Question 11

How is malaria and sickle celled anemia an example for a ‘tradeoff’

Answer 11

Heterozygous individuals have an advantage because they are resistant to the malaria parasite because they have two different copies ( so only little symptoms show)

Question 12

What is stabilizing selection?

Answer 12

When natural selection favours intermediate phenotypes

Question 13

What is directional selection?

Answer 13

Natural selection favours one extreme of the distribution

Question 14

What is disruptive selection?

Answer 14

When natural selection favours both extreme ends of the distribution

Question 15

What are the 3 kinds of natural selection

Answer 15

1. Stabilizing
2. Directional
3. Disruptive

Question 16

What does natural selection do to a population?

Answer 16

Diversifies it

Question 17

Which two types of natural selection could lead to the development of new species?

Answer 17

Directional and disruptive

Question 18

What is sexual dimorphism?

Answer 18

When there is differences between the male and female in the same species

Question 19

What are the positives and negatives of sexual dimorphism?

Answer 19

Can have a high fitness in the sense of reproduction (because it’ll attract a mate)
Low fitness eg. uses energy

Question 20

What is sexual selection

Answer 20

Makes with sexually selected traits

Question 21

What are 4 positives of sexual selection?

Answer 21

1. Chosen more often than females
2. Produce offspring
3. Traits are passed onto the next generation
4. Higher frequency of the gene in these traits

Question 22

What is genetic drift?

Answer 22

Sudden changes in genetic makeup in a population

Question 23

What are some examples of things that can cause genetic drift?

Answer 23

Earthquakes, flood and fires

Question 24

What is the bottleneck effect?

Answer 24

When a large number of individuals are killed and only a small population is left. By chance the new population may not resemble the old one

Question 25

The bottle neck effect causes...?

Answer 25

Genetic drift

Question 26

What is the founder effect?

Answer 26

Displaced population can have a different genetic makeup

Question 27

What are two types of geological events that can cause evolutionary change

Answer 27

1. Continental drift | 2. Mass extinction

Question 28

How many mass extinctions have there been?

Answer 28

5 major extinctions

Question 29

What is gene flow?

Answer 29

When individuals move in and out of populations

Question 30

What 2 things does gene flow do to populations?

Answer 30

Reduce differences and increases variability

Question 31

What leads to adaptive evolution?

Answer 31

Natural selection

Question 32

What is a hybrid?

Answer 32

An offspring of parents of two different species

Question 33

What is the biological species concept?

Answer 33

A group of populations whose members can interbreed in nature and produce fertile offspring

Question 34

What is speciation?

Answer 34

Evolutionary process in which one species splits into two species

Question 35

Selection on one population leaded to accumulated differences that prevent what?

Answer 35

Successful interbreeding

Question 36

Barriers to successful interbreeding can lead to...?

Answer 36

Speciation

Question 37

What are two main types of reproductive barriers?

Answer 37

Pre zygotic and Post zygotic

Question 38

What are 5 types of pre zygotic barriers and what do each mean

Answer 38

1. Habitat isolation- rarely meet 2. Temporal isolation- different breeding times 3. Behavioural isolation- don't recognize each other 4. Mechanical isolation 5. Gametic isolation- gametes are incompatible

Question 39

What are 3 post zygotic barriers? Explain each

Answer 39

1. Reduced hybrid viability- don't survive/ fully develop 2. Reduced hybrid fertility- don't produce functional gametes 3. Hybrid breakdown- weak or infertile

Question 40

What is allopatric speciation

Answer 40

Geography prevents interbreeding | Ex. land masses, bodies of water

Question 41

What is adaptive radiation?

Answer 41

Evolution of many diverse species from a common ancestor

Question 42

When does adaptive radiation especially occur?

Answer 42

When a few organisms colonize new unexploited habitat

Question 43

When speciation is gradual but not recorded in fossil record, why is this?

Answer 43

Sedimentation is slower than diversification

Question 44

What are the 7 major events in the history of life?

Answer 44

1. Origin of earth 2. Prokaryotes 3. Atmospheric oxygen 4. Single celled eukaryotes 5. Multicellular eukaryotes 6. Animals 7. Colonization of land

Question 45

What was the earlier evidence of life?

Answer 45

Stromatolites: Similar to present day photosynthetic prokaryotes

Question 46

Who first tries to find evidence for abiotic synthesis of organic molecules?

Answer 46

Miller

Question 47

What are photocells?

Answer 47

Created by adding lipids to water