How do these two species of Finch vary? Variation Red-browed finch House finch Why do they vary? How do these two species of Finch vary?

DON’T TOUCH ANYTHING ON THE TABLES All you need is a pen or pencil

WALT understand how adaptation can lead to evolution.

How are these species of Finch adapted? Variation Red-browed finch House finch How are these species of Finch adapted?

Charles Darwin Modern ideas of evolution started with Charles Darwin. In 1831 Darwin set out as a ship’s naturalist on HMS Beagle, it was a 5 year voyage to South America and the South Sea Islands.

Voyage of the Beagle Darwin recorded observations of plants and animals that he saw on the voyage. In the Galapagos islands Darwin observed that each of the islands had similar types of finches, iguanas and tortoises, but that each was different to make the most of local conditions.

What are different types of beaks suited to? Your task is to plan an investigation to find out which birds’ beak would be best at helping a bird to survive on a diet of a particular seed. You have 7 minutes of discussion with your group, then 5-10 mins to write up what you’re going to do. Time: 10 minutes Expectation: Everyone to complete first 3 finches.

Writing up an investigation Aim Apparatus Method Fair test Prediction Results Diagram Conclusion

Imagine The birds have been separated by a storm onto two different islands. There has been a drought and most food types have died out, so the food that is available on each island is now different.

Finch Distribution

How does this model help us to understand why different species exist in different environments?

Darwin’s Theory Darwin only observed one type of finch on the mainland- similar to the Galapagos Small Ground Finch. He proposed that all finches evolved from the one species that lived on the mainland.

What factors would have to exist for a species to be able to change? Genetic variation due to mutation. Competition; for food, mates, territory, to avoid predation. ‘Survival of the fittest’ the organism that is best adapted to its environment will survive. Reproduction- passing on the advantageous alleles to the offspring. Leading to change in the species over time- evolution.

https://youtu.be/BcpB_986wyk

In whichever way you’d like, explain the process of evolution.

What if . . . The seeds on Espanola started to increase in size? What would you expect to happen immediately to the population of Small Ground Finches? What would you expect to see happen to the population over the next 20 years? What would happen if the size of the seeds decreased again in the future?

Exam question (5 marks) Two different species of butterfly: Amauris Hypolimnas Both species can be eaten by most birds. Amauris has a foul taste which birds do not like, so birds have learned not to prey on it. Hypolimnas does not have a foul taste but most birds do not prey on it. Describe, in terms of natural selection, how Hypolimnas may have developed its wing markings

Mark Scheme: Mutation caused changes in marks in Hypolimnas. Competition; less predation of butterflies with these markings. These butterflies survived to reproduce; other butterflies were eaten. Advantageous allele/gene was passed on to offspring. Over time population of Hypolimnas start to look more like Amauris; evolution Remember: make your answer specific to example given.