Natural selection is a theory developed by Charles Darwin Individuals whose physical and behavioral characteristics are best adapted to their environment (habitat) have better chances of reproducing and passing on their DNA to future generations. Individuals whose physical and behavioral characteristics are best adapted to their environment (habitat) have better chances of reproducing and passing on their DNA to future generations. Video

Class Starter 1.Describe the theory of natural selection in your own words. _____________________________________ _____________________________________ _____________________________________ 2.Explain how the same members of a species can develop different traits. _____________________________________ _____________________________________ _____________________________________ _____________________________________

Example of Natural Selection - 2 variations of the peppered moth light variation is best adapted to living in the country (it camouflages with the birch trees) dark variation is best adapted to living near factories (where tree trunks have turned black due to the factory smoke)

Light Peppered Moth- best adapted to living in the country

Black peppered moth- best adapted to living near factories

How did the black moth come to be? The black moth arose as a result of a genetic mutation in the gene responsible for wing colour.

How do members of the same species develop different traits? 1.Genetic Mutations – Every time your DNA replicates in order to make new cells it can make mistakes – These mistakes result in changes to your DNA and thus changes to your physical traits. – A new trait might be more successful in a specific environment, causing it to become more frequent in the population

Genetic Mutations

How do members of the same species develop different traits? 2.Sexual reproduction: – Parents pass on their traits to their offspring through their DNA. – Each offspring inherits a different combination of their mother and father’s genetic information (genes).

Different Combinations of Genes

How do members of the same species develop different traits? Certain offspring may be born with a combination of genes that is more successful than his/her parents or siblings. This will make the individual ‘more fit’ and therefore more likely to survive in their environment and pass on their DNA to future generations.