EVIDENCE FOR
EVOLUTION
Topic 5 - 2015
Year 10 Biology
TOPIC 5 – EVIDENCE FOR EVOLUTION
Things to cover:
1. Biogeography
2. Fossil record
3. Comparing molecules
4. Comparing anatomy
Work to do:
1. Worksheet – Long, long ago
2. Worksheet – Fossils
3. Worksheet – Patterns, order & organisation
Ideas to know:
 Biogeography
 Fossil record
 Types of fossil
 Fossil formation
 Archeopteryx lithographica
 DNA hybridisation
 Comparing proteins
 Comparing anatomy
 Homologous structures
 Analogous structures
REVIEW TOPIC 4
Are these statements about natural selection true or false?
•
Natural selection is another name for evolution.
__________
•
Natural selection is a theory proposed by Charles Darwin.
__________
•
Only the biggest individuals of a species survive and pass
on their characteristics.
•
__________
Natural selection favours individuals that are best adapted to
their environment.
__________
•
Evolution occurs as a result of natural selection.
__________
•
Variation within a species is very important if natural
selection and evolution are to take place.
__________
Complete these sentences about evolution:
1. Fossils show that all species have _____________ from simple life forms over the space of 3
_____________ years.
2. Each population that arose showed _____________ due to gene mutations.
3. Natural _____________ allowed individuals with _____________ most suited to their
environment to survive and breed.
4. Useful genes were passed to the next generations so new ______________ gradually
evolved.
5. Many species became extinct due to _____________ in the environment or the appearance
of new competitors, _____________, or diseases.
BIOGEOGRAPHY
•
Refers to ____________________ ____________________ of ____________________
•
Evolution would suggest that ____________________ would exist between
____________________ and those ____________________ in that ____________________
in the ____________________.
•
If organisms arose by ‘special creation’, we would expect that similar habitats in different
parts of the world would contain similar plant and animals.
•
But they don’t….
•
We find that ____________________ ____________________ live in similar habitats in
different parts of the world.
•
In Australia, our deserts contain spinnifex ____________________ and
________________________________. American deserts contain ____________________.
The FOSSIL RECORD
•
Refers to the record kept of the ____________________ of
____________________ in the ____________________
•
Fossils don’t have to be ____________________!
•
They can also be:
− ____________________
− ____________________
− ____________________
− ____________________
− ____________________
− ____________________ , etc
•
Steps:
1. Organism ____________________
2. ____________________ by dirt, mud, silt or lava before ____________________ can
occur
3. The material that lies above the fossil ____________________, forming
____________________
4. This ____________________ the fossil.
Even if the organism itself ____________________ at a later stage, the __________________
will remain in the rock.
•
Fossilisation is rare!
− It has to be __________________ __________________ it ____________________.
− It has to be buried in an area that ____________________ ____________________.
ie. no silt, no fossil
− Whole organism may not be fossilised due to an attack by ____________________
before being buried.
− Different types of fossil form under ____________________ ____________________
and environments.
− Fossilized remains only form in the ____________________ of
____________________, which need food, oxygen, water and warmth.
The FOSSIL RECORD
•
Finding a fossil is also rare!
− You need to know ____________________ to ____________________! And even
then, its hard!
− May only find ____________________; not enough to get the whole picture of that
organism.
− May only find ____________________ ____________________.
Good scientists never rely on one piece of evidence to draw a good
____________________.
− May only find ____________________ ____________________.
Many species are ____________________ ____________________ – meaning that
males and females differ.
•
If a new species evolves from an ____________________ ____________________, the fossil
record should contain organisms that are ____________________ with some
____________________ of ____________________ the modern and ancestral forms.
•
•
One fossil type found is
____________________ ____________________.
REPTILE FEATURES
BIRD FEATURES
COMPARING MOLECULES
•
Scientists can ____________________ a variety of molecules
in order to determine whether two species are
____________________ or ____________________ related.
•
eg:
− ____________________
− ___________________________________
____________________ & ____________________
•
DNA HYBRIDISATION
− All organisms contain DNA in their cells.
− Double stranded DNA can be ____________________
so that it ____________________ into
____________________ ____________________.
− A single strand from one organism can be placed
next to a single strand from another organism and
____________________ ____________________.
− The two single strands will bond to each other (hybridise) where complementary
bases are found.
− If the strands are similar, a high amount of pairing will take place.
•
− eg.
+
 _________________________________________
− eg.
+
 __________________________________________
COMPARING PROTEINS
− All organisms share a number of proteins.
− ____________________ is an ____________________ needed for
____________________.
− If we compare the ____________________ ____________________
____________________ of Cytochrome C in different organisms, we find that closely
related organisms have very similar Cytochrome C.
COMPARING MOLECULES
Organism
No. of changes in amino acid sub
units relative to humans
Human
Rhesus monkey
Whale
Chicken
Tuna fish
– The _________________ that two species _________________ from a
_________________ _________________, the more time there has been for
_________________ to occur in the amino acid sequence.
– This shows that _________________ and _________________ are more closely
related than _________________ and _________________.
COMPARING ANATOMY
•
Scientists look for similarities in ____________________ ____________________ and
____________________ in order to investigate common ancestry.
•
These similarities are called ____________________.
•
Species that share ____________________ ____________________ share similarities
because they have a ____________________ ____________________.
•
eg:
− The ____________________ of all ____________________ is very similar in the
number and structure of the bones present.
•
____________________ ____________________ also exist.
•
These are ____________________ in ____________________ that have evolved due to
____________________ ____________________ ____________________
____________________.
•
eg:
−
SQ10 - CHAPTER 3
Question
Response
1. What name was given to the landmass to which Australia
belonged 250 million years ago?
2. a) How many supercontinents were formed?
b) How many years ago?
c) What were their names?
3. List the 5 pieces of evidence to support the theory that supercontinents once existed:
i.
ii.
iii.
iv.
v.
4. What is a fossil?
5. What could be considered to be a
fossil?
6. Briefly describe the 4 steps
involved in the formation of a
fossil. (4marks)
1.
2.
3.
4.
7. What is the name given to a scientist who studies fossils?
8. What is absolute dating?
9. What chemical is used for absolute dating?
10. What is relative dating?
11. What is the Scientific name for
the bird skeleton found in Bavaria?

12. Name the features of this skeleton that were similar to
modern birds.



13. Name the features of this skeleton that were similar to
reptiles.
14. What conclusion did scientists
draw from the discovery of this
fossil?
15. Why are so few organisms
preserved as fossils?
(2marks)


16. Why is the fossil record
incomplete?
(2marks)




Question
Response
17. List the 4 principles that form the 1.
basis for Darwin’s theory of
2.
natural selection.
3.
4.
18. What term is given to the formation of a new species?
19. List the 4 different types of
evidence used to support
Darwin’s theory of evolution.




20. What is convergent evolution?
21. Compare analogous and
homologous structures.
(2 marks)
Analogous
Homologous




22. a) Describe the process of DNA
hybridisation?
b) How is it used to identify
related organisms?
23. Compare artificial and natural
selection.
(2 marks)
Artificial selection
Natural selection
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