* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Science - Evolution and inheritance
Survey
Document related concepts
Unilineal evolution wikipedia , lookup
Hindu views on evolution wikipedia , lookup
Plant evolutionary developmental biology wikipedia , lookup
The Descent of Man, and Selection in Relation to Sex wikipedia , lookup
Acceptance of evolution by religious groups wikipedia , lookup
Creation and evolution in public education wikipedia , lookup
Saltation (biology) wikipedia , lookup
Catholic Church and evolution wikipedia , lookup
Paleontology wikipedia , lookup
Evolutionary history of life wikipedia , lookup
Transcript
Science - Evolution and inheritance - Year 6 Lesso Learning n objective 1 To recognise that living things have changed over time and that fossils provide information about living things that inhabited the Earth millions of years ago Introduction Main Activity Plenary Assessment Tell children that living things have changed over time (and are still changing). Can they think of any animals or plants that used to live on Earth but no longer exist? E.g. lots of different dinosaurs, Dodo, Great Auk, Sabretoothed cat, Quagga, etc. (see hamilton resources). These animals and plants are extinct Point out that although some became extinct 65 million years ago (dinosaurs) or thousands of years ago (sabre-toothed cats), others have only become extinct in more recent years (quagga).Read about extinction at http://www.oum.ox.ac.uk/thezone /animals/extinct/define.htm Tell children the story of the peppered moth and how it apparently adapted to the changed environment it found itself living in (see hamilton resources). It shows natural selection in that the dark moths were more likely to survive than the pale moths in areas where the soot had darkened the pale birch tree trunks, and therefore the ratio of the two types changed – both had existed before the industrial revolution. Eventually in some areas the pale moths could have died out. So species are still changing (evolution is happening). Visit www.bbc.co.uk/schools/gscebitesize/science/aga/evoluti ontheories/ theoriesfevolutionrev5.shtml Children to write a short recount. Point out that there are a number of endangered species that could easily become extinct soon. Can children name any? E.g. giant Pandas, several species of butterflies in the UK, Leatherback Turtles, Black Rhinoceros, Wild Bactrian Camels (2 humps), Sumatran Orang-utan, Iberian Lynx, Siberian tigers, etc. (There is usually something in the press about a current concern.) What reasons can the children give for why animals become extinct e.g. – their habitats are being destroyed, humans are killing them for food &/or body parts (e.g. rhino horns), predators from other places are being introduced, humans are killing them because they cause damage to crops or property, etc. Identifying scientific evidence that has been used to support or refute ideas Ask children what they can remember about fossils. Useful websites http:// www.discoveringfossils. co.uk/ whatisafossil.htm http://www.oum. ox.ac.uk/thezone /fossils/into/form.htm http://www.bbc.co.uk/nature/fossils Watch video http:// www.youtube. Com/watch?v = SEDfRy6DQns Ext: Children to make & play board game ( children to play in groups of 3 or 4 Discuss how zoos & wildlife organisations are trying to save some species by breeding them & then releasing the offspring into the wild. Sometimes 1. Explain that living things are changing over time. 2. That some plants and animals have become extinct, and that others may become extinct in the near future. 3. Fossils give us some information about animals and plants that lived millions of years ago. 4. Describe how some species are being helped to survive Science - Evolution and inheritance - Year 6 Remind chn that not all plants & animals that die become fossils; the conditions have to be just right. Fossils provide information about some living things that inhabited the planet millions of years ago. We know about more recent extinctions because species were found, known, described, drawn, photographed, etc. while examples were still alive. The remains of bones in the stomach area of a fossil or a skeleton can show what was eaten by the larger organism, the teeth might indicate the type of diet, the remains can be carbon dated, fossil faeces (coprolites) show the kinds of food eaten, etc. 2 Recognise that living things have changed over time and that fossils provide information about living things that inhabited the Earth millions of years ago species become extinct in one area of the world, but are still present elsewhere, so they can be re-introduced to an area, e.g. in UK success stories of red kite & beavers. More countries are protecting habitats & particular species by introducing new laws & actually prosecuting offenders. Ask if any of the children have ever been fossil hunting? Where did they go? Did they discover any fossils? View power point – Mary Anning Show children some fossils, photographs (she hamilton resources) or preferably actual specimens. Can children spot similarities or differences to plants and animals alive today> Show children where Lyme Regis is on a map of the UK Children to make notes Reinforce that Mary was from a poor family with little education however she become a leading authority on the subject & many well-known palaeontologists/geologists/scientists visited her in Lyme Regis, discussed fossils with her & asked for her advice. Note Discuss how unusual it was for a woman to be renowned as a scientist/palaeontologist in the 19th century, never mind the fact that she was from a poor family & had virtually no education (her spelling & grammar was not very good in the notes, letters, etc. that she left). Show the children the wellknown tongue twister written in 1908 by Terry Sullivan which is 1. Talk about Mary Anning’s contribution to palaeontology. 2. Understand that fossils found in Lyme Regis originated at the bottom of a sea. 3. Describe Mary Anning’s life. Science - Evolution and inheritance - Year 6 Almost 200 million years ago Lyme Regis was a muddy sea further south than it is now (plate tectonics could be mentioned briefly!). It was in a warmer climate there (like the Mediterranean now) and there was a lot of marine life. When the wide range of creatures died their remains sank to the bottom of the sea & many formed fossils. thought to refer to Mary Anning (hamilton resources). Children to write & draw a comic strip to describe all aspects of Mary’s life (see template). Ext: children to make detailed sketches of fossils 3 Recognise that living things produce offspring of the same kind, but normally offspring vary and are not identical to their parents. Ask children if they look like their relations? Or do they look completely different. (show Beckhams ask for similarities /difference in children) Optional smart notebook – match families Ask when do we see humans who look very similar to each other – identical twins? Show photographs (hamilton resources). Briefly discuss difference between identical twins and fraternal twins. (See Hamilton resources.) Explain that we all humans have 23 pairs of chromosomes – (one set from each parent) which are made up of thousands of genes, each of which carries the information for a certain feature. Children imagine they are going to create a new type of dog. Which two sorts of dogs will they cross? What will the offspring look like? Children to produce labelled drawing. Children can use http://www.justdogbreeds.com/dog-breeds.html to research breeds. Children to present & discuss the new breeds they have created with peers. Ext: Selective breeding in dogs (see sheets). Show children smart notebook evolution dog breeding. Point out to children that if you show a young child a picture of a dog of any breed they usually recognise it as a dog, even though they may look very different. Ask for suggestions & list the features that make a dog a dog. Some of the features are similar to a cat or a horse or a cow, so how do we (or young children) tell the difference? Discuss. Reporting and presenting findings of enquiries Identifying scientific evidence I can: 1. Recognise that living things produce offspring of the same kind, but the offspring usually vary & are not identical to their parents or to each other. Science - Evolution and inheritance - Year 6 Look at Mr Men power point on variation and inheritance. Show hamilton resources what do children think will happen if you cross a Labrador and a poodle? Explain selective breeding is used in plants as well as animals especially dogs. 4 Identify how animals and plants are adapted to suit their environment in different ways and that adaptations may lead to evolution Ask the children who Charles Darwin was? What was he famous for? He wrote a book called On the Origin of Species in 1859. In it he explained his theory of evolution by natural selection. Explain to the children that the organisms that are best suited to their environment will survive whereas those least suited to the environment will die. Those surviving organisms will go onto breed and therefore the adaptations they have will be passed to the next generation. Explain Evolution as the gradual changing of the features of living organisms through long periods of time to produce species which are in some way unlike the original ones. Natural means that it occurs in nature – it is not made, caused by or processed by humans, and selection means the act of choosing. Darwin took 20 years to prepare his theory for publication after he had sailed on HMS Beagle for 5 years visiting South America, Australia and Select children & give them various adaptions e.g. fork, chopsticks, cocktail stick etc. Tell them that due to environmental changes there is now only one food source e.g., maltesers or something similar. Ask the children to test out which one of them is best suited to the environment e.g. the best adaptations. Which of them will survive and which of them will die? Explain to the children that this is natural selection. Ext activities: Children try to survive as a young bird at http://web.archive.org/web/20150319214617/http://ww Tell the children that different people have other theories about creation. E.g. Aborigines believe that all forms of life, the Ancestors, lay sleeping under the crust of the Earth until time split & they were awakened. In the Pacific islands there were stories of the first people hatching from eggs laid by a bird-headed god or turtle. 2. Explain the difference between identical & fraternal twins in simple terms. 3. I can suggest what happens when two different kinds of dog (or other animal) are crossed. Identify scientific evidence that has been used to support or refute ideas Presenting findings 1. Define evolution as the gradual changing of the features of species over time. 2. Explain that Charles Darwin first published Science - Evolution and inheritance - Year 6 the Galapagos. Watch u tube clip What Mr Darwin Saw by Mick Manning & Brita Granström. Darwin found lots of interesting evidence for his theory during the 5 year expedition. Visit http://darwin200.christs.cam.ac.uk/pa ges/index.php?page_id=j read diff sections together. w.nhm.ac.uk/nature-online/evolution/what-isevolution/natural-selection-game/the-evolutionexperience.html Look at the discussion drawing about blackbirds together (session resources) & use it to explain how competition can lead to evolution. The Hindu god of creation, Brahma, was believed to have used the lotus flower he had been sitting on to create the world & all living things. this concept in 1859. 3. Explain in simple terms how natural selection works. The first book of the Bible (Genesis) explains how God created the world & everything on it in 6 days & so on. (Children to complete homework on life of Charles Darwin). Scientists now have an explanation that covers millions of years Evolution 5a Identify how animals and plants are adapted to suit their environment in different ways and that adaptations may lead to evolution Explain to the children that although Darwin is accredited with the theory of evolution and natural selection another scientist Alfred Russel Wallace also worked out the theory. Watch u tube clip Alfred Russel Wallace/ The Collectors/ Natural History Museum https://www.youtube.com/watch?v= DDyiyl0DKWw&feature=youtu.be Remind the children that it was a joint paper that was published to the scientific community but it was Children to write a fact file about Alfred Russel Wallace Ext: Children to play Darwin’s finches game http://www.bbsrc.ac.uk/society/schools/keystage12/darwin.aspx. and Work together on the evolution game at http://www.sciencechannel.com/games-andinteractives/charles-darwin-game.htm before giving children the opportunity to have a go in pairs. Plenary: Display the fact files that children have produced & give children the opportunity to tell the class what they discovered. Discuss how the investigations and thinking of many scientists can be brought together to clarify scientific ideas. Scientists all over the world still work Identifying scientific evidence that has been used to support or refute ideas Explain both Wallace’s and Darwin’s contribution to the theory of natural selection. Science - Evolution and inheritance - Year 6 Darwin who published his book which the general public also read. Wallace made an enormous collection of specimens while travelling around Singapore, Malaysia & Indonesia – 110,000 insects, 7,500 shells, 8,050 bird skins & 410 mammal & reptile specimens (more than 5,000 of these were species new to science). See some of his insect collection in hamilton resources. They show mimicry of inedible butterflies by others & a range of similar but different stag beetles, weevils, chafers & others. One of the best known examples of Darwin’s observations while travelling on HMS Beagle is the variety of beaks in finches found on the various islands of Galapagos. – look at bbc bitesize – Darwin’s finches. 5b Identify how animals and plants are adapted to suit their environment in different ways and that adaptations may lead to evolution Introduce Gregor Mendel (1822-1884) See power point. An Austrian monk who experimented experiments on pea plants. He realised that features were being passed down from parents to offspring in ‘pieces’ (one corresponding ‘piece’ from each parent), which we now call genes (see Hamilton resources). together/co-operate to establish new theories today. Children to write a summary explaining Mendel’s experiments. Ext: Children to try pollination station On A kid’s guide to Gregor Mendel father of genetics. Ask the children to reflect on their learning What have they learned? Recap the punnet diagram if needed. Identifying scientific evidence that has been used to support or refute ideas . Give a simple explanation of Mendel’s pea experiments Science - Evolution and inheritance - Year 6 and his contribution to the understanding of evolution. 6 Identify how animals and plants are adapted to suit their environment in different ways and that adaptations may lead to evolution One of the conclusions that Darwin came to in his theory of natural selection is that plants & animals change by chance (we now call this genetic mutation) & he also concluded that some of these changes made the animal or plant better suited to their environment. If plants & animals are well-suited to their environment they are more likely to survive long enough to pass their changes to their offspring (3rd conclusion of Darwin’s). They have adapted better to their surroundings/ habitat. Show children a picture of a cactus (hamilton resources) and a small cactus plant . Ask children how are cacti adapted to living in desert areas (i.e. very dry conditions –cold at night in deserts/ hot during day, & some deserts are cold day & night)? They have stems that can store water (they swell after a rain storm & can store a supply of water for many months) & a widespread shallow root system that can collect water from a large area (the roots are shallow so Discuss how plants produce large numbers of seeds, but that only a few of them succeed in growing into mature plants (able to produce seeds themselves – have offspring). What problems do seeds & young plants meet in the environment? List ideas on f/c, e.g. competition for water & sunshine, animals/birds eating them, trampled, landing in an unsuitable place, weather conditions, etc. On a large piece of paper draw a 3 by 3 grid & label the cells: path, tree, lawn/field, compost heap, patio, bonfire, garden bench, pond, flower bed (adapt labels for your school grounds). One child holds the ‘seeds’ (c.50 1cm2 pieces of paper or large seeds like sunflower) & throws them up in the air to see where they land (any that miss the paper have been eaten by birds or small animals). Discuss what will happen to the seeds that have landed in the various cells – the fight for survival. Some children could blow at the ‘seeds’ to imitate the wind! Establish that lots of seeds are necessary for a few to survive! Follow this up by looking at grassed areas (use quadrats to mark similar size areas) in different parts of the school grounds, e.g. under a tree, in open sunshine & compare the growth of the grass & other plants. Take photos of areas for further comparisons. Discuss possible reasons why the areas look different. Share children’s plant designs & discuss the features they have included. Will those plants survive in the chosen environment? Planning different types of scientific enquiries Recording data Presenting findings Describe how plants are adapted for different environments. 2. Explain why plants produce large numbers of seeds. Science - Evolution and inheritance - Year 6 that they collect the water in the top layers of the soil as soon as it has fallen). They have spines instead of leaves that minimises the surface area of the plant. This means that they lose less water from the leaves / transpiration. The spines have the added advantage that they also protect cacti from animals that might want to eat them! Watch the video clip at http://www.bbc.co.uk/programmes/p 00xcr7m that describes how plants are adapted to live in very cold conditions. Ask children to note adaptations that help the plants in this environment. Plants in the rainforests have a range of adaptations to help them survive, e.g. epiphytes (hamilton resources) live on the surfaces of other plants (mostly tree trunks & branches) in the canopy (top layer of vegetation) which allows them to make the most of the available sunlight. Their aerial roots take in moisture from the air – they have a layer of dead cells on their surface which absorbs the water. Leaves of rainforest plants often have a waxy surface with pointed tips (drip tips – see session resources) at the end to enable excess rainwater to run off. Many plants have buttress or stilt roots (session resources) which help Show children the PowerPoint document about plant adaptation in UK environments from http://www.saps.org.uk/primary/teaching-resources/88primary-article-one. In pairs children research and produce a labelled diagram of a plant showing its adaptations to its environment (list of suggested plants in hamilton resources), e.g. ivy has special roots on its stems to climb up tree trunks, walls or fences, hawthorn has spines & holly has spiky leaves to discourage animals from eating them, etc. Ext: Design a plant for a particular habitat – make a detailed drawing showing the special features that will help it survive & possibly make a model of their new plant. . Science - Evolution and inheritance - Year 6 anchor large plants as the root systems are quite shallow in the thin layer of soil found in the forests. 7 Identify how animals and plants are adapted to suit their environment in different ways and that adaptation may lead to evolution. Recap on how plants are adapted – previous lesson. Explain we are going to find out ways in which animals are adapted to their environment. Animals can live in very hostile environments, e.g. hot deserts & Antarctica. They have adapted to these habitats. Show children video clip approx. 22 mins u tube how animals adapt animal atlas http://www.watchknowlearn.org/Cate gory.aspx?CategoryID=2855 Look at the Discussion Drawing (session resource) together & ask what children think? Hopefully Darwin’s theory of natural selection will be used to explain how giraffes evolved to have long necks. Use this example to discuss an earlier theory of evolution put forward by Chevalier de Lamarck in 1809 (see above and session resources). 8 Identify how animals and plants are Ask children which adaptations of both plants & animals they have found the most amazing? Ask children to research animal adaptations which help them Survive their environments e.g. camels, penguins See differentiated recording sheets. Listen to the camel adaptation rap at https://www.youtube.com/wat ch?v=YpGg-m8wyY4. Notes: Features that help camels survive in sandy deserts, e.g. a double row of long eyelashes, nostrils which can close, store of fat in hump, long strong legs, thick leathery pads on flat, wide feet & on knees. They also have thick fur to keep them warm during cold, desert nights. Penguin features webbed feet for powerful swimming & their bodies are streamlined to reduce drag in water. Their wings, shaped like flippers, help them ‘fly’ underwater at speeds up to 15 mph. Penguins have tightly packed, overlapping feathers which provide waterproofing & warmth. Their thick skin with a layer of blubber (fat) underneath keeps them warm & their black back feathers absorb warmth from the Sun. Point out that humans have evolved to walk on two legs instead of four, unlike other closely related creatures. Ask Planning different types of enquiries to answer questions Presenting findings Give examples of how animals have adapted (evolved) to suit their environment. Discuss vestigial structures Identifying scientific evidence that Science - Evolution and inheritance - Year 6 adapted to suit their environment in different ways and that adaptations may lead to evolution Look at a picture of a giraffe having a drink (hamilton resources). It has to use that position because of its long legs – despite having a long neck! However it is dangerous because giraffes are quite vulnerable when in this position if they are suddenly attacked by a predator. So although its height is an advantage for finding food & provides a good view of its surroundings, it is a disadvantage for drinking water. Penguins have evolved to keep warm in very cold conditions, but they can get overheated if the Sun is shining so they have also had to evolve patches which have few or no feathers, e.g. around the foot of their beak & their eyes, to allow heat to escape from their bodies. They lift up their wings to lose heat too by increasing their surface area & allowing air to circulate under their wings where again there are not many feathers. They also pant like a dog sometimes. Animals & plants are still evolving, adapting to changes in their environment. The climate in the world is changing, so animals have to adapt to warmer, colder, drier or wetter weather conditions in different parts the children to discuss and record what advantages and disadvantages that gives us? E.g. Free hands to carry food, hold tools, carry babies, etc. enabling early humans to appear larger & more intimidating & helping early humans to move over wide, open landscapes quickly & efficiently; disadvantages: back pain & other skeletal problems, less ability to climb steep slopes (like goats) or trees, more easily seen by predators. Ask children to think about how might humans involve in the future? What might cause the adaptations? E.g. much warmer global temperatures, rising sea levels. What features would children like to have, e.g. ability to fly or to hold their breath under water for long periods of time. See differentiated recording sheets. Dew claw - on the inside of a dog's paw serves? The claw is the dog's thumb. Because a dog runs on the balls of its feet and four digits, the claw no longer serves a purpose, though sometimes they do seem to help grip things with their dew claws. Dew claws have to be regularly clipped because they don’t touch the ground when the dog is walking or running & so don’t get worn down. Appendix - used to store microbes that helped to digest plant matter, but it is no longer needed in the human. Some scientists think that perhaps gut bacteria hide there during a bout of diarrhoea as a small thin appendix is more likely to become inflamed, so natural selection may be favouring large appendixes. We also still have a tail hidden inside our bodies – the bones are there still – called the coccyx at the end of the spine. However some muscles are still attached to these bones, so it is has been used to support ideas Presenting findings Understand that adaptations can have disadvantages as well as advantages. Explain my ideas about future human evolution. Science - Evolution and inheritance - Year 6 of the world or move to live in a different place where the environment still suits them. In recent years some birds that used to only breed on the continent have started breeding in the UK, e.g. Barnacle Geese and Egyptian Geese. A species of whale: a dwarf sperm whale was spotted off the UK coast for the first time in 2011. Humans are affecting the habitats of many creatures too, e.g. there are fewer hedges than there used to be because farmers prefer large fields in which to use their large farm machinery such as combine harvesters; the use of pesticides on farms has introduced chemicals that birds of prey cannot deal with in their diet. Humans have on average become taller & fatter than our recent ancestors & we are also living longer. unlikely that we will lose our coccyx. Tonsils -