life science presantation of EVOLUTION

1. Bheki Hadebe
This is the presentation by Bheki Hadebe from different authors, for more
details find the credits page on the last slide. Hope you will find this info useful.
Enjoy the lesson!!

2. Evolution and Bio-Diversity
•Survival and Extinction
•Theory of Evolution
•Natural Selection

3. Survival and Extinction
Extinct Species
•Baji Dolphin
Endangered Species
•Siberian Tiger
•West African Black Rhino
Species : A group of living organisms
consisting of smaller individuals capable of
interbreeding and exchanging genes.
MDPettitt, Siberian Tiger, July 17, 2008,
Creative Commons License

4. Survival and Extinction
◦Population – A group of organisms of
one species that interbreed and live in the
same place at the same time.
◦Example:
◦ Deer Population
LoneTown, Deer ‘White Tail Deer’, February 20, 2011,
Creative Commons License

5. Survival and Extinction
◦Removal of genes from gene pool

6. Survival and Extinction
◦Fossil Records
◦Majority of species are extinct
◦Give us insight to Earth’s history

7. Survival and Extinction
Fossil Records Continued
◦Displays how species have evolved
IvanWalsh, Fossils and Dinosaurs
from Beijing Museum, December 5,
2009, Creative Commons License

8. Evolution
Evolution Definition
◦Any change across successive
generations in the heritable
characteristics of biological
populations

9. Evolution
Charles Darwin
Ryan Murphy M.Ed. www.sciencepowerpoint@gmail.com
◦ Created his own theory of evolution
◦ All species from common ancestry
◦ Branching pattern of evolution - natural selection

10. Evolution
Darwin’s Theory of Natural
Selection
◦ Differential Survival
◦ Essential to Darwin’s theory
◦ Limited quantities of space and resources
◦ Those most fit will survive

11. Evolution
Best displayed through
comparisons of:
Fossils
Modern species
Changes are displayed in different ways

12. Evolution
Natural Selection
◦Provides a mechanism for evolution
◦Process to explain evolution

13. Natural Selection
The gradual non-random process through
which biological traits become more or less
common in a population

14. Natural Selection
How it works
◦ Traits are passed down generations
◦ Beneficial traits are passed on
◦ Negative traits disappear
◦ Important traits are traits that:
◦ Benefit reproduction and/or survival

15. Natural Selection
◦Mutations
◦Some diversity comes from mutations
◦Beneficial mutations are passed on
◦Mutations can become part of genes
◦Example: Giraffes’
long necks
JRobertMoore, Giraffe, January 13, 2007, Creative Commons License

16. Natural Selection
Geographic Isolation
◦A species is physically separated
◦Plays important role in evolution
◦Two diverse groups form

17. Natural Selection
◦ Environmental Factors
◦ New predators or prey
◦ Low food supply
◦ Finite resources

18. Credits to:
◦ Pettitt, M. D. (2008: 17). Siberian Tiger. Creatice Commons License.
◦ Lonne Town, Deer White Tail Deer. (2011: 20). Creative Commons
Licenses .
◦ Ivan Walsh. (2009, 05). Fossils and Dinosaurs. Beijing Museum.
◦ Moore, J. R. (2007: 13). Giraffe. Creative Commons License.
◦ www.sciencepowerpoint@gmail.com
◦ Ryan Murphy M.Ed. www.sciencepowerpoint@gmail.com