Evolution

Question 1

Evidence of evolution

Answer 1

• Comparative anatomy
• Taxonomy
• Geology and fossils
• Biogeography

Question 2

Vestigial organs

Answer 2

Reduced organs that exist in an organism but are not necessary/used

Question 3

Ontogeny

Answer 3

Early developmental stages of distantly related organisms are similar

Question 4

Homologous structures

Answer 4

A group of organisms is similarly constructed no matter how they live

Question 5

Taxonomy

Answer 5

Classification of organisms, life is hierarchical

Question 6

Scala Naturae

Answer 6

Nature gets increasingly more advanced

Question 7

List the categories, from minor to major

Answer 7

Species
Genus
Family
Order
Class
Subphylum
Phylum
Kingdom

Question 8

Order of evolutions

Answer 8

Fish > Amphibians > Reptiles > Mammals

Question 9

Name a whale ancestor

Answer 9

Pakicetus, 50 mil y/o
small 4 legged animals
had characteristic ear structure only found in whales

Question 10

How do we know baleen whales evolved from toothed whales?

Answer 10

Baleen whales have grooves in upper jaw
Whale foetuses have tooth buds

Question 11

Geology

Answer 11

Fossils record evolution.
Earth is old af

Question 12

Biogeography

Answer 12

Organisms in different areas, ven if they have the same climate etc, are different but may occupy the same niche

Question 13

(2 theories of) evolution

Answer 13

1. Current living organisms are all related by descent/common ancestry
2. Occurs via process of natural selection

Question 14

Who proposed continental drift?

Answer 14

Alfred Wegner

Question 15

Relevance of Pangea

Answer 15

Allowed organisms to cross now continents, distribution of common ancestor

Question 16

Characteristics of natural selection

Answer 16

• Variation
• Heritable
• Mortality
• Survival of the fittest

Question 17

Variation

Answer 17

Organisms (within the same species) differ from one another

Question 18

Heritable

Answer 18

Differences within a species are passed from generation to generation

Question 19

Mortality

Answer 19

Many more organisms are born than survives to sexual maturity/reproduces

Question 20

Survival of the fittest

Answer 20

Variation which makes one offspring more successful than another will have a greater chance of being passed onto the next generation

Question 21

Population dynamics

Answer 21

When a population grows beyond the carrying capacity/quantity of available resources the population will crash until it is able to grow exponentially again

Question 22

Evolution can’t…

Answer 22

Get worse before it gets better nor can it correct mistakes

Question 23

How did the eye evolve?

Answer 23

1. light sensitive cells
2. cup allows more light in
3. constriction of cup opening focuses light
4. lens further focusses light
5. bigger bulge in lens allows more focus

Question 24

Allometry

Answer 24

Parts of the body grow at different rates

Question 25

Why is having 2 copies of our genome relevant?

Answer 25

Allows one to be changed without necessarily effecting the organisms totally

Question 26

Og mammal?

Answer 26

Dimetrodon

Question 27

Bimodal distribution

Answer 27

When one trait is preferable/at a higher frequency than another

Question 28

Example of bimodal distribution

Answer 28

Lazuli Buntings (birds) Male phenotype is blue, female is brown. Increasing number of brown males who hang out with males who assume its a female so dont attack. But during breeding brown males sneak in and mate the females

Question 29

Who fucked about with peas?

Answer 29

Gregor Mendel (Laws of inheritance)

Question 30

Heterozygote

Answer 30

Different copies of the same factor/gene

Question 31

Homozygous

Answer 31

Identical copies of a factor/gene

Question 32

Proportion of gene combination

Answer 32

p2 + 2pq + q2 = 1

Question 33

Mutations

Answer 33

spontaneous changes in the genetic information

Question 34

Cause of mutations

Answer 34

Copying errors Environmental factors (radiation) Jumping genes

Question 35

Affect of mutations

Answer 35

DNA sequence changes Changes in chromosomal structure Change in number of chromosomes

Question 36

Importance of mutations for evolution

Answer 36

Creates variants and thus changes in frequency

Question 37

Consequences of mutations

Answer 37

Harmful (majority) Neutral Beneficial (rarely)

Question 38

Sexual reproduction

Answer 38

Is a source of variation as the combination of genes are re-combined and re-shuffled every generation

Question 39

Recombination

Answer 39

Reshuffling of genes within the chromosome

Question 40

Polygenic trait

Answer 40

A trait controlled by multiple genes

Question 41

How is a phenotypical trait controlled

Answer 41

Nature (genetics) and Nurture

Question 42

Stabilising selection

Answer 42

Selection favours mean over tail But selection = loss of variation

Question 43

Directional selection definition

Answer 43

One tail is favoured over the other, mean moves left or right

Question 44

Describe directional selection

Answer 44

Can oscillate frequently due to environmental factors but retains variation

Question 45

Red Queen Hypothesis

Answer 45

There is always pressure to evolve counter-adaptations

Question 46

Disruptive selection

Answer 46

Uses the same graph and principles as bimodal distribution. The median is not favoured and is disadvantageous. Tails favoured over mean

Question 47

Frequency-dependent selection

Answer 47

A phenotype is only favoured when it is either rare or common

Question 48

Hardy Weinberg principle

Answer 48

the genotype frequency won't change between generations if there is no selection