VocabularyAdaptation: An Adaptation is a physical, behavioural, or physiological trait that helps an animal survive its environment.
Generation: A group of animals, plants, or people that descend from common ancestry. Mutations: A permanent change (positive or negative) in a creature or plant. This could either give the thing better survival or worse survival. |
Today's Target: Understand what natural selection is, and how animals use adaptation to pass on strong genes
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What is Natural Selection?
Natural selection is the process of which nature decides what traits and adaptations will be passed down for a creature or animal.
How does nature decide? It depends on the adaptations specific animals have for their environment. "Nature" is best described as an external force we do not have control over: birds, weather, predators, etc. |
In the video you watched yesterday, there is a part where a chameleon eats beetles, but he only eats the beetles that are dark green.
If this chameleon continues to always eat the dark green beetles (because the light green are camouflaging) the dark green beetles will die out. This means that the light green beetles have the better adaptation for survival: They can't be seen as easily. |
Generations and Mutations?
A generation is a single step below a common ancestor. Your parents would be a generation above you, and your siblings (if you have any) would be in the same generation as you.
In the image on the right, the horizontal coloured sections are generations that are grouped together. For animals and plants, it is easier to see the generational steps as all things have different life spans. Mutations are the permanent changes (usually small) that a generation may have. A mutation can be a positive or negative, it all depends on the environment.
If a mutation is a favourable adaptation, it will allow the animal to survive and pass down its adaptations to the next generation. If a mutation is an unfavourable adaptation, it will not likely survive to pass down its adaptations to the next generation. As time goes on, the animal with the best adaptations to survive will pass down its mutations, making the animal in generation 5 look very different from the animal in generation 1. |
Interactive Lab
We are going to head to this interactive lab and tinker around with generations, mutations, and natural selection to see it better in action. Click the text below.
Natural Selection Interactive Lab Dominant: A dominant gene is a trait in an animal or person that will more frequently show up in later generations. Recessive: A recessive gene is a trait in an animal or person that will less frequently show up in later generations. |
Lab Checklist
- Include Brown Fur as a dominant mutation. How frequent are brown furred bunnies?
- Start over and make brown fur a recessive mutation. What differences do you notice
- How many generations does it take to have brown furred bunnies dominant? (Use Wolves, Recessive brown fur, Summer Season)
- Using the Teeth mutation, add Tough food. How does the bunny population change? What are the effects?
- After a few generations, turn on limited food as well. What changes?
- Use the graph on the bottom to click and see the changes in population based on adaptations.
Discussion
- Why do you think more wolves appeared with more bunnies?
- How did the mutations help your bunnies survive different situations?
- Did you try to reverse any of the mutations back to the original state?
Adaptations in animals around the world are based on natural selection. Things that do not prolong the survival are not passed onto the next generation.