Variation in a populationVariation – all individuals within a species

have different features/ characteristics, and they do not all survive to adulthood to have

offspring

• All the individuals compete for food, shelter, etc. within their environment, or ecology, and the slight variations give some a better chance of survival

• Inheritance – because they are more successful and have similar offspring, some variations occur more often than others, and over many generations a noticeable change or adaptation can be ‘seen’ in the population

• This is evolution

Evolution - Variation

• The variations in the population are random. A species can not guess which adaptations will be useful in the future

• It is the surviving-individuals in a population passing on their traits that leads to an overall change of traits in the population.

• Over many generations, evolutionary adaptations arise.

Variation is not chosen

• * Emphasise that these variations are tiny and the changes happen over a really really long time!

• The next activity is to show how changes to the environment and variation can lead, over time, to evolutionary adaptation.

Activity for variation

Things to remember

• The class represents the population and its variation

• The children are not aware of what environmental change will happen – in the same way that individual organisms can not choose their traits to pre-empt their environmental change

The evolution game

You will slowly evolve from an animal in the sea

Your ecology has changed

• Make goggle hands to show excellent vision

• Cup ears for good hearing

• Perform jazz hands to show you can sense vibrations around you

• Everyone with excellent eye sight sit down because you would not be able to see in all the mud!

• Those that have hearing or sense of vibrations survive!

Your environment was the sea bed

• Wave a fin to swim

• Run on the spot to go on land

• Put your hands on the ground to live underground

Your ecology has changed

• All swimming survive. There is no food on land yet and the ground is too hard to live in!– You are now an animal with fins…

Your environment was coral reef

What colour animal are you?• Black• Purple• Green

Your ecology has changed

• All green animals survived because of their camouflage.

You survived!

Your environment was seaweed

• Outcomes– Though variation in our population was

exaggerated, this is how some traits stay in the population and some do not.

– Variation - all individuals within a species have different features/ characteristics, and they do not all survive to adulthood to have offspring.

– Those that do, pass on their traits which leads over many generations to evolutionary adaptation

Pair discussion

– Please visit our website for more resources and lesson plans

www.primaryevolution.com

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