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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.
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Evolution and Bio-Diversity
•Survival and Extinction•Theory of Evolution•Natural Selection
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
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
Survival and Extinction◦Removal of genes from gene pool
Survival and Extinction
◦Fossil Records
◦Majority of species are extinct◦Give us insight to Earth’s history
Survival and Extinction
Fossil Records Continued ◦Displays how species have evolved
IvanWalsh, Fossils and Dinosaurs from Beijing Museum, December 5, 2009, Creative Commons License
EvolutionEvolution Definition
◦Any change across successive generations in the heritable characteristics of biological populations
Evolution Charles Darwin
Ryan Murphy M.Ed. [email protected] ◦Created his own theory of evolution ◦All species from common ancestry◦Branching pattern of evolution - natural selection
EvolutionDarwin’s Theory of
Natural Selection◦Differential Survival ◦Essential to Darwin’s theory◦Limited quantities of space and resources◦Those most fit will survive
Evolution Best displayed through
comparisons of: Fossils
Modern species
Changes are displayed in different ways
EvolutionNatural Selection
◦Provides a mechanism for evolution◦Process to explain evolution
Natural Selection
The gradual non-random process through which biological traits become more or less common in a population
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
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
Natural Selection Geographic Isolation
◦A species is physically separated◦Plays important role in evolution◦Two diverse groups form
Natural Selection◦Environmental Factors◦New predators or prey◦Low food supply◦Finite resources
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. ◦[email protected] ◦ Ryan Murphy M.Ed. [email protected]
