Transcript Sheet 1
Introducing Charles Darwin - a famous scientist. Darwin’s idea to explain evolution was natural selection. That: • living things produce offspring which vary — they are not all the same, • there is a shortage of resources (food, light, places to live, animals to mate with etc.), • individuals that do best in this ‘competition for survival’ will tend to leave more offspring, passing on their successful features to the next generation. This is adaptation. Charles Darwin • Therefore, over time, organisms with certain characteristics will become more common, while others will become less common and may die out. • Over a long period of time, these small differences between individuals add up to large differences, and eventually new species are produced. This is evolution. Yuck! Look at this caterpillar. • How do you think it happened that he is so disgusting to eat? • What caused him to taste so bad? • Anybody got any theories? Ideas? • Darwin did! The toilet roll timeline! Using a toilet roll to show over how many evolution takes place. Each piece of paper is the same as about 100 years. Use the time line to help you understand how many years ago dinosaurs started evolving in to birds. The diversity of modern birds Parrot, flamingo, penguin, owl, duck, emu and peacock. Sheet 1: • Modern birds. • Children’s names and how many years ago they were born. • How many years ago your parents were born. Sheet 1: Gouldian finches. Gouldian finches require fire for its food. It feeds mainly on the seeds of one plant speargrass. It is only after fires (started by accident or by man) have cleared the undergrowth that the birds can reach the seeds on the ground. Sheet 1: Emperor Penguins. At the southern extremity of the world lives the Emperor Penguin, better adapted to the cold than any other animal on earth. Short feathers made up of tiny filaments that trap the air in a continuous layer all around the body enable the adults and chicks to survive some of the coldest conditions on Earth, the Antarctic ice-cap in winter. Sheet 2: • How many years ago your grandparents were born. • World War 2 (65 years ago). • First computers (65 yrs ago) • World War 1 (100 yrs ago) • Extinction of the passenger pigeon (115 years ago). Passenger pigeon extinction Sheet 2: Perhaps the best known bird extinction is the passenger pigeon, a North American species. There was a population of an estimated two billion birds in colonial days, when huge overflying flocks would darkened the sky. European colonists cut down the beech forests that provided food for the pigeons, and slaughtered the birds for food. The last wild pigeon was shot by a boy in 1900; Martha, the last captive bird, died in Cincinnati Zoo in 1914. Sheet 3: Charles Darwin’s theory of natural selection (150 years ago). Sheet 3: extinction of the Dodo. 350 years ago. The dodo is the tragic symbol of bird extermination. This large, flightless, turkey-sized pigeon lived on the tropical island of Mauritius. A fruit-eater, it had little reason to move fast or fly. It was easy prey for man the hunter. Sheet 20: Roman’s invasion. 2000 years ago. About half a toilet roll! First birds (100 million years ago). The oldest known bird fossil. Archaeopteryx had three toes armed with claws and long, strong legs. Clearly it walked and perched like a bird. Its head had the reptilian feature of jaw bones. Its spine was extended into a bony tail - just like a reptile's. On both sides of the tail bones, clearly visible, were the characteristics of birds - feathers. Fifth from last sheet: Pterosaurs (180 million years ago.) Pterosaurs, or flying dinosaurs, took the ascendancy. These massive creatures had wings of skin, stretched between one enormously elongated finger and their flanks. Last sheet: 200 million years ago. The mounted skeleton of a Velociraptor, showing the very bird-like quality of the smaller theropod dinosaurs. As birds evolved from these theropod dinosaurs, many of Their features were changed/ adapted. However, it's important to remember that the animals were not "trying" to be birds in any sense. For example, small theropods probably evolved the first feathers. These short, hairlike feathers grew on their heads, necks, and bodies and provided insulation. Wigglies (made up food!) Use your imagination: • You are in the jungle (not in your classroom standing around a table). • You eat wigglies that live in the canopy (not wool on the table). • You are hungry and you need to eat before you die (you need to grab the wigglies/worm). • Every man/woman for themselves (you have no friends in the jungle). Let the fight for survival commence! • You have 5 seconds to grab your wigglies, then you must step away from the table. • How many do you have? Hunting Caterpillars How to eat: •One person to be in charge of the stop watch. •One person at a time. •Collect one caterpillar at a time. •Put it on the tape before the next person goes. •Put them on the tape in the order you collect them. Who would be eaten first? Why did you find so many caterpillars at first? Best Beak? • Different kinds of birds eat different kinds of foods, because they are specialised. Their beaks have adapted to be the best shape for picking up the food they like best and is most available to them. In this experiment we predict which ‘beak’ will be best for each ‘food’ type. • Lay out the bird ‘food’ in 5 locations, then divide into 5 groups. Each group will have a set of ‘beaks’. At each location, predict which ‘beak’ you think will work best for that food, then tests the ‘beaks’ to see if their prediction is correct, recording on your worksheet as you go. • Based on the results of the experiment, match the beak to the food on the final worksheet. What have you found out today? Hint: use these words to help you. evolution adapt adaptation natural selection competition survival species environment habitat variation species Yuck! Look at this caterpillar. • How do you think it happened that he is so disgusting to eat? • What caused him to taste so bad? • Anybody got any theories? Ideas? Evolution • Did the caterpillar think about it? • Make the decision for itself? • Or did it just happen over time?