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What is Natural Selection? What are the mechanisms of Natural Selection? How do Beneficial Traits effect Evolution? What are some limitations of Natural.

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Presentation on theme: "What is Natural Selection? What are the mechanisms of Natural Selection? How do Beneficial Traits effect Evolution? What are some limitations of Natural."— Presentation transcript:

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2 What is Natural Selection? What are the mechanisms of Natural Selection? How do Beneficial Traits effect Evolution? What are some limitations of Natural Selection? What are three common myths about Evolution through Natural Selection?

3 Natural Selection is the mechanism of Biological Evolution. Biological Evolution is the process whereby earth’s life changes over time through changes in the genes of a population Since Early Greek Philosophers, people have tried to explain the origin of species. Charles Darwin and Russel Wallace were the first to create a credible explanation for the Origin of Species.

4 Natural Selection states that since there is a limited supply of resources needed for survival, there will exist competition for those resources. This Competition will SELECT a natural trait or adaptation in an organism. This organism will survive and pass on its trait to its offspring, allowing that offspring to have a better chance for survival.

5 Much research and loads of evidence has been found to support Evolution through Natural Selection. Our Six Kingdoms of Life and the Tree of Life stems from Natural Selection. The Fossil Record proves that life existed in ancient times. The Fossil Record though helpful in understanding Evolution, still has Major Gaps in it and only represents 1% of all species that have ever lived. There is still a lot we do not know about the Origin of Species

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7 Darwin and Russel created their theory of Evolution without the knowledge of DNA and heredity. Natural Selection involves changes in a population’s genetic makeup through successive generation. Populations, not individuals, evolve by becoming genetically different.

8 Genetic Variability starts with a mutation. Mutations are random changes in the structure or number of DNA molecules in a cell that can be inherited by offspring. Mutations can be triggered by exposure to UV rays, natural mistakes caused by replication and mutagens. Mutations are not malignant in nature. The environment chooses whether a mutation is beneficial or not.

9 The Environment chooses Mutations that will help individuals survive and produce offspring. A Beneficial Mutation is considered an Adaptation or Adaptive Trait. For Natural Selection to occur, a trait must be heritable. In order for Natural Selection to Occur that inheritable trait must lead to differential reproduction.

10 Genetic Resistance is the ability of one or more organisms in a population to tolerate a chemical designed to kill it. Antibacterial Resistance Pesticide Resistance Herbicide Resistance

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12 Natural Selection acts on the individual while Populations Evolve. In other words, when genes change and mutate and give an individual in a population a better chance for survival, Evolution will occur. When Environmental Conditions change there are three responses an organism can have: Adapt to the new conditions Migrate to a new area Become Extinct

13 Change in Environmental Conditions can lead to such an adaptation only for genetic traits already present in a population’s gene pool or for traits resulting from mutations. Reproductive Capacity is another limitation. You can have the most beneficial trait ever, but if you die before you can reproduce, then you cannot pass it on. Very long reproductive cycles Low number of offspring

14 Survival of the Fittest is not Survival of the Strongest Fittest means the ability to survive and pass on your genes to your offspring You cannot create your own traits Acquired traits cannot be passed down Evolution has no grand master plan. There is no perfect species in science.


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