01b evidence of evolution (7.4)
TRANSCRIPT
The Evidence for Evolution
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
Evidence for Evolution
• Types of evidence Darwin used to support his theory:– Biogeography– Homologous and analogous features– Vestigial features– Competition within populations
Biogeography + Darwin’s Observations
Key Observation from Galapagos Islands
Testing Darwin’s Hypotheses:Hawaiian Islands
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 islands. Dodo Bird Extinction within 175
years – Mauritius Islands (Indian Ocean)
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
Analogous Features
• Structures that perform same function in two species but are not similar in origin or anatomy
Vestigial Features
• Features that no longer serve the function they do in similar species
http://rebeccamcc.blogspot.com/
http://paxarcana.wordpress.com/2009/08/25/your-appendix-may-actually-do-something/
http://www.youtube.com/watch?v=lBkiT0zyYm0
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
Homework
• Page 303 # 1,2,4-7