Evolution by Natural Selection

Question 1

Who developed the theory of evolution by natural selection?

Answer 1

Charles Darwin in 1859

Question 2

What did Darwin make?

Answer 2

Key observations about the world around him

Question 3

What was Darwin’s first observation?

Answer 3

Noticed organisms produce more offspring than survive

Question 4

What was Darwin’s second observation?

Answer 4

There is variation in characteristics between members of the same species

Question 5

What was Darwin’s third observation?

Answer 5

Some of these characteristics can be passed on from one generation to next

Question 6

What was Darwin’s fourth observation?

Answer 6

Individuals best adapted to their environment are more likely to survive

Question 7

Why did Darwin write his theory?

Answer 7

To explain his ideas

Question 8

What was the first element of his theory?

Answer 8

Individuals within a population show variation in their phenotype

Question 9

What was the second element of his theory?

Answer 9

Selection pressures create a struggle for survival

Question 10

What are examples of selection pressures?

Answer 10

Predation, competition etc

Question 11

What was the third element of his theory?

Answer 11

Individuals with better adaptation are more likely to survive and reproduce

Question 12

What was the fourth element of his theory?

Answer 12

Adaptations passed onto offspring

Question 13

What was the fifth element of his theory?

Answer 13

Over time, the proportion of the population possessing the advantages adaptation increases

Question 14

What was the sixth element of his theory?

Answer 14

Over generations, this leads to evolution as the advantageous adaptations become more common

Question 15

Based from his theory, what do we now know about certain individuals?

Answer 15

That they show variation in phenotypes as a result of genetic variation (different alleles)

Question 16

What happens to advantageous alleles?

Answer 16

Passed onto offspring

Question 17

Who if Alfred Russell Wallace?

Answer 17

He worked at the same time as Darwin and played an important role in the development in the theory of natural selection

Question 18

What did Wallace come up with?

Answer 18

Independently came up with the idea and wrote to Darwin about it

Question 19

What did Wallace and Darwin do together?

Answer 19

Published their papers on evolution and acknowledged each others work although they disagreed on the mechanisms (the way it works)

Question 20

What did Wallace’s observations provide?

Answer 20

Evidence to support the theory

Question 21

What did Wallace realise which provided the evidence to support his theory?

Answer 21

That warning colour used to deter predators was an example of advantageous adaptation that had evolved by natural selection

Question 22

When did other scientist start to pay attention to Darwin and Wallace’s ideas?

Answer 22

When Darwin published his book ‘On the Origin Species’

Question 23

What is covered in the book and why is it memorable?

Answer 23

He gave evidence to support the theory and is why he is better remembered than Wallace

Question 24

What are the 3 pieces of evidence for evolution?

Answer 24

-Fossil Record
-DNA
-Molecular

Question 25

What are fossils?

Answer 25

Remains of organisms preserved in rocks

Question 26

What is the fossil record evidence for evolution?

Answer 26

By arranging fossils in chronological order, we can observe gradual changes in organisms

Question 27

What is the DNA evidence for evolution?

Answer 27

-Theory of evolution suggests that all organisms evolve from a common ancestor -Closely related species diverged more recently

Question 28

What happens to organisms DNA that have diverged more recently?

Answer 28

Have more similar DNA as less has passed for base sequence to change

Question 29

What is evolution caused by?

Answer 29

Gradual changes in base sequence of DNA

Question 30

What happens in eukaryotes with DNA evidence?

Answer 30

DNA is found in a nucleus but there is also DNA in mitochondria and we can look at the differences in mitochondrial DNA

Question 31

What is the molecular evidence for evolution?

Answer 31

We can compare the sequence of amino acids in proteins and compare antibodies

Question 32

What happens to organisms that have diverged more recently in relation to molecular evidence?

Answer 32

Have more similar molecules as less time has passed for changes to proteins to occur

Question 33

What is Phylogeny?

Answer 33

Is the name given to the evolutionary relationships between species

Question 34

What is a Phylogenetic Tree?

Answer 34

A diagram that represents the lines of evolutionary descent of different species, organisms, or genes from a common ancestor

Question 35

Draw and Label an example of a Phylogenetic Tree.

Answer 35

See Notes

Question 36

What is the first advantage of using Phylogenetics?

Answer 36

Classification uses knowledge of phylogeny in order to confirm the classification groups are correct of causes them to be changed

Question 37

What is the second advantage of using Phylogenetics?

Answer 37

Is a continuous tree where as classification requires discreet groups into which some organisms might not quite fit

Question 38

Why is the hierarchical nature of linean classification misleading?

Answer 38

As it implies different groups within the same rank are equivalent