What would happen if this polar bear was
What would happen if… …this polar bear was bright pink? …this cactus didn’t have spikes? …this camel didn’t have a hump?
Adaptations Species are adapted to suit their environment Those that are not well adapted to their surroundings will die. Those that are well adapted will survive and reproduce Adaptations are passed on to the next generation This is survival of the fittest
Evolution… A gradual change in characteristics of a plant or an animal over time
The giraffe – Evolution by natural selection - Charles Darwin
Once upon a time… Giraffes once had variation in neck lengths
Giraffes compete to eat leaves from the trees and bushes
Over time the leaves start to thin out on the lower branches…
…to the point where the short-necked giraffes can no longer reach
The short-necked giraffes can no longer eat so die
The long-necked giraffes survive and reproduce to pass on their genes
The population of giraffes all have long necks. They have adapted to their environment
Your task Complete the comic strip to describe how giraffes evolved by natural selection (diagrams and descriptions) Try to use the following key words - Natural selection - Variation - Competition - Genes - Survive - Reproduce - Adaptation
Natural selection - Giraffe
Your experiment Investigate Darwin’s theory on finches. Use different types of ‘beaks’ to pick up the food. How much food does each type of beak pick up in 1 min? You can only pick up one bead at a time. • • You will be in groups of 3 Each person will have a different shape ‘beak’ Each person has to pick up as many bits of food as possible in 1 min Record the amount of food each beak picked up Repeat the experiment 3 x Take an average of the results Draw a graph to show and compare results Write conclusion about results
Beak Tweezers Tongs Spoon 1 2 3 Average
Exam question (5 marks) Natural selection is one of theories of evolution. State the person whose theory it is, and how it occurs using an example.
Exam question 1 mark: (Charles) Darwin 4 marks from the following: Giraffe population has variation in neck length Giraffes with short necks cannot reach branches Giraffes with short necks die Giraffes with long necks survive Giraffes with long necks reproduce Gene for characteristic of long neck passed on to next generation
Mimic… Copying
Mimicry Can be copying the surroundings Can be copying other animals Why would they do that?
Copying surroundings
Copying other animals
Now find the animals in the following pictures…
E. g. This is a stick insect
You now have to find him!
FIND THE FOX
WHAT IS HIDING HERE?
Which animals mimic? On your tables create a list of animals that either 1. Mimic their surroundings 2. Mimic other animals Surroundings Other animals
- Slides: 30