Evolution

Question 1

True or false, humans have evolved from apes

Answer 1

False

We evolved from a common ancestor which we share share with apes

Question 2

Name Charles Darwin’s mechanism for evolution

Answer 2

Natural selection

Question 3

Explain Charles Darwin’s travels

Answer 3

He spent 5 yrs on HMS beagle where he travelled the world, he went to the Galápagos Islands and studied finches

He concluded that the design of beak was linked to food available, and so only birds with the correct beak would survive, and pass on there offspring

( survival of the fittest )

Question 4

What prompted Darwin to think evolution as a slow process

Answer 4

He read a book by Lyell who suggested that fossils were evidence of animals who lived a long time ago.
Also promoted idea of uniformitarianism- the idea that in the past the earth was shaped by forces that we still see today

Question 5

What did Alfred Wallace and Charles Darwin’s do together

Answer 5

Propose the theory of evolution

Question 6

What year did Charles Darwin’s publish the origin of species
What was this

Answer 6

1859

Theory of evolution by natural selection

Question 7

What 4 things did Charles Darwin’s observe

Answer 7

1) offspring are generally similar to the parents
2) no two individuals are identical
3) organisms have the ability to produce large numbers of offspring
4) populations tend to remain fairly consistent in size

Question 8

Describe limb structure as evidence for evolution

Answer 8

Despite being adapted for different functions, all have the same underlying structure

Suggests different species have evolved from a common ancestor

Question 9

Explain embryonic development as evidence for evolution

Answer 9

Embryos of mammals pass through the same stages as fish embryos
They all look similar
Implies embryonic development has a common origin

Question 10

Describe the fossil record as evidence for evolution

Answer 10

Show organisms have changed over time
We can date fossils back
Many fossil organisms no longer exist
You can compare DNA extracted from some fossils

Question 11

What are some criticisms of the fossil record

Answer 11

It is often incomplete
Only hard parts can be fossilised
Sometimes conditions are not right for fossils to form

Question 12

Describe molecular evidence for evolution

Answer 12

Closely related species have very similar biological molecules
Genes can be compared by the sequence of the DNA
The more similar the closer related they are
The more different the further related they are

Question 13

Define variation

Answer 13

The presence of differences between individuals

Question 14

What is intraspecific variation

Answer 14

The differences between members of the SAME species

Question 15

What is interspecific variation

Answer 15

The differences between members of DIFFERENT species

Question 16

What are the two causes of variation

Answer 16

Genetic variation- combination of alleles

Environmental variation - hair cut, scars, tattoos etc

Question 17

Why is it that even identical twins could be different

Answer 17

A mutation

Question 18

What is discontinuous variation

Give example

Answer 18

Discrete categories wit no intermediates
Blood type

It is qualitative
Environmental has little or no effect

Question 19

What is continuous variation

Answer 19

No defined categories
Example is height
Quantitative
Can be influence by genes and environment

Question 20

Why is it good to have genetic variation in a population

Answer 20

Without genetic diversity organisms can not adapt to changes in the environment such as-
Change in climate
New disease
New pest

Means that whole crops and cattle can be destroyed

Question 21

Define adaptations

Answer 21

A variation that enhances the survival and long term reproductive success of a an individual

Question 22

What will a well adapted individual be able to do

Answer 22

Defend itself demo predators
Fight off disease
Survive change in environment

Question 23

What are the three types of adaptations

Answer 23

Behavioural
Physiological
Anatomical

Question 24

Define behavioural adaptations

Eg

Answer 24

The way an organism acts
They can be inherited or learnt
-playing dead, blinking

Question 25

Define physiological adaptations

Eg

Answer 25

Processes that take place inside the organism

-holding water

Question 26

Define anatomical adaptations

Eg

Answer 26

Any physical feature that enhances the survival of the organism
-shell for protection, waxy cuticle

Question 27

What is natural selection

Answer 27

There is genetic variation ina population due to mutations
Large numbers of offspring are produced
There will be selection pressure , those who have selective advantage are more likely to survive
They then pass on this mutation to their offspring
This happens over many generations and this increases the presence of this advantageous allele

Question 28

What are the four types of selection pressures

Answer 28

1. availability of food
2. Predators
3. Diseases
4. Physical and chemical factors ( extremes of light or temperature)