Recall: a species is a group of living organisms with similar features Members of the same species can breed together Example: All dogs are members of the same species by they don’t all look the same Recall: a species is a group of living organisms with similar features Members of the same species can breed together Example: All dogs are members of the same species by they don’t all look the same

List 5 characteristics of dogs that are similar. List 5 characteristics that are different.

Differences between members of the same species are called variation Can I get 10 volunteers... 2 from each table How many different ways could you classify these 10 people? Differences between members of the same species are called variation Can I get 10 volunteers... 2 from each table How many different ways could you classify these 10 people?

What Causes Variation Variation is cause by either environmental factors or inherited factors This type of variation is passed on in genes from parent to offspring This type of variation is influenced by living conditions and surroundings

What are some of the inherited characteristics of humans? – Eye colour, hair colour, height, blood type Any other inherited characteristics? What are some of the inherited characteristics of humans? – Eye colour, hair colour, height, blood type Any other inherited characteristics?

Environmental variation is cause by differences in living conditions and surroundings What do you think causes environmental variation? – Food supply, temperature, water supply, humidity, disease How would these affect variation? – Influence the way you look, speak, and how you do things Environmental variation is cause by differences in living conditions and surroundings What do you think causes environmental variation? – Food supply, temperature, water supply, humidity, disease How would these affect variation? – Influence the way you look, speak, and how you do things

Some inherited characteristics can be affected by environmental factors

Which are inherited, environmental or both? InheritedEnvironmentalBoth Blood Group Wears glasses Tongue Rolling Freckles Speaks Italian Dyed Pink Hair Neutral Eye Colour Height Welsh Accent

Continuous vs. Discontinuous Variation

Examples of Variation in Humans Discontinuous: Blood Type, hair colour Continuous: Height, eye colour Discontinuous: Blood Type, hair colour Continuous: Height, eye colour

What about plants? Plants and organisms from other kingdoms are also affected by inherited and environmental factors

Plenary: True or False 1.Members of the same species all look the same FALSE! Members of the same species have similar features but do not look the same

2. Only living things that are members of the same species can breed together to produce fertile offspring TRUE! Some species can be interbred – but their offspring are infertile

3. Variation only occurs in animals FALSE! Variation occurs in all living things, including plants and bacteria

4. Variation caused by environmental factors can be passed from parent to offspring FALSE! Only inherited characteristics are passed from parent to offspring

5. Identical twins are more alike than most but even they are not exactly the same TRUE! Identical twins inherit the same features but they have different fingerprints

6. The ability to roll your tongue is an inherited characteristic. TRUE! Have you inherited this type of variation?