1. 9A: Inheritance and variation
Lesson 6: Variation within species
Natural selection

2. Learning objectives
Define species and identify differences between species
Explain how the variation between species and between individuals of the same species means some organisms compete more successfully, which can drive natural selection and changes in a population
Analyze a graphical representation of variation within species

3. What is a species?
a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding
species are adapted to their environments in specific ways
Find three differences between these species

4. Environment and variation
Species change over time to suit their environment
variations exist because of DNA and genes which are different within a species
New characteristics that are beneficial will lead to increased survival
Those that survive will have more offspring with the same beneficial characteristic

5. Examples of environmental variations

6. Genetics and variation
Mutations occur in genes
Environmental pollution, toxic waste, radiation
Random mistakes or switches in genes when dividing

7. Task Complete worksheets in the Booklet Read about
1.21, 1.22, 1.25, 1.26
Read about
environmental causes of variation (p.12-3)
genetic causes of variation (mutation/combinations) (p.14-5)