1. The Evidence for
Evolution

2. Darwin’s Voyage – BBC 2009
• Part 1:
• http://www.youtube.com/watch?
v=ZtZb6GZgniI
• Part 2:
• http://www.youtube.com/watch?
v=xGAVnbSW6kQ&feature=related

3. Evidence for Evolution
• Types of evidence Darwin used to support his
theory:
– Biogeography
– Homologous and analogous features
– Vestigial features
– Competition within populations

4. Biogeography + Darwin’s Observations

5. Key Observation from Galapagos
Islands

6. Testing Darwin’s Hypotheses:
Hawaiian Islands

7. Testing Darwin’s Hypotheses
• When non-native
mammals and
amphibians introduced
to islands, they have
been able to thrive.
This eliminates the
possibility that they
can’t survive on remote
Dodo Bird Extinction within 175
islands.
years – Mauritius Islands
(Indian Ocean)

8. Homologous Features
• Structures with common evolutionary
features which serve different functions in
modern species
•
Video on homology: http://www.youtube.com/watch?v=XgXT9sU6y18&feature=related
http://www.xspore.com/community/drama/6876-evolution-vs-religion-4.html

9. Analogous Features
• Structures that perform same function in two
species but are not similar in origin or
anatomy

10. Vestigial Features
• Features that no longer serve the function
they do in similar species
http://paxarcana.wordpress.com/2009/08/25/your-appendix-mayactually-do-something/
http://rebeccamcc.blogspot.com
/
http://www.youtube.com/watch?
v=lBkiT0zyYm0

11. Competition Within Populations
• Thomas Malthus (Principle of Population)
showed that all population are limited in size by
the environment (food supply)
Darwin’s thoughts:
• All species produce more offspring than can
survive to reproduce
• This results in competition for resources
between members of the same species
• Environment might be favouring certain
individuals

12. Homework 
• Page 303 # 1,2,4-7