Darwin and his evidence Biology Revision – CHAPTER 7 – Variation and Evolution Part 1 Variation Differences between individuals or species is called variation it can be caused by our development (environment) or genetics, some characteristics are controlled by both. Complete the table below by giving examples of human characteristics controlled by these different factors. Natural selection The theory of natural selection was developed by the scientist Charles ………………….. ……………………. in a population gives some individuals an advantage and others a disadvantage in surviving in their environment The organisms that that have more advantageous characteristics are more likely to ………………………. and …………………….. The offspring of these advantageous individuals will inherit these advantageous from their parents …………………… Genetics Environment Both Darwin and his evidence What evidence did Darwin collect to develop his theory of natural selection? Fossils Fossil evidence Why is the fossil record incomplete? Using the diagram describe some the changes that have happened to the horse throughout its evolution What are fossils? Draw a series of annotated diagrams to show how fossils form

Antimicrobial resistance Biology Revision – CHAPTER 7 – Variation and Evolution Part 2 Antimicrobial resistance Using diagrams explain how bacteria such as MRSA have evolved a resistance to antibiotics Genetic engineering What is genetic engineering? What are the advantages of genetically modified crops (GM Crops)? What are the disadvantages of GM crops? Selective breeding What is selective breeding? Evolutionary trees Extinction What does extinction mean? What are some possible causes of extinction? Explain how a meteorite caused the extinction of the dinosaurs From the evolutionary tree diagram above which group is most closely related to: Humans

Darwin and his evidence Biology Revision – CHAPTER 7 – Variation and Evolution Part 1 Variation Differences between individuals or species is called variation it can be caused by our development (environment) or genetics, some characteristics are controlled by both. Complete the table below by giving examples of human characteristics controlled by these different factors. Natural selection The theory of natural selection was developed by the scientist Charles ………………….. ……………………. in a population gives some individuals an advantage and others a disadvantage in surviving in their environment The organisms that that have more advantageous characteristics are more likely to ………………………. and …………………….. The offspring of these advantageous individuals will inherit these advantageous from their parents …………………… Darwin Variation Genetics Environment Both Blood group Hair length Height survive reproduce Eye Colour Language Skin colour Natural hair colour Scars and tattoos Body mass (weight) genes Darwin and his evidence What evidence did Darwin collect to develop his theory of natural selection? Fossils Fossil evidence Why is the fossil record incomplete? Using the diagram describe some the changes that have happened to the horse throughout its evolution What are fossils? The mineralised remains of organisms hard parts that have been preserved from millions of years ago. Erosion has destroyed fossils (particularly very old ones, soft bodied organisms completely decay and leave no trace. Studied unique animals and plants of the Galapagos islands and South America. Selective breeding of pigeons Fossils Draw a series of annotated diagrams to show how fossils form Over time the horse has changed by: Fewer toes Larger body Larger head + teeth Longer legs

Antimicrobial resistance Biology Revision – CHAPTER 7 – Variation and Evolution Part 2 Antimicrobial resistance Using diagrams explain how bacteria such as MRSA have evolved a resistance to antibiotics Genetic engineering What is genetic engineering? What are the advantages of genetically modified crops (GM Crops)? What are the disadvantages of GM crops? The transfer of genes from one organism to another. Grow faster – more food produced Pest resistant crops – less pesticides Genes may be transferred to other species through cross pollination Long-term impacts on health are not known Selective breeding What is selective breeding? Evolutionary trees Extinction What does extinction mean? What are some possible causes of extinction? Explain how a meteorite caused the extinction of the dinosaurs Individuals with desired characteristic are selected to breed. Best offspring are selected and are bred with other good offspring. Over many generations of selective breeding the whole population has the desired characteristics. Complete loss of all members of a species Meteorite impact Volcanism Climate change New predators New diseases New competitors Destruction of habitats Pollution From the evolutionary tree diagram above which group is most closely related to: Humans Meteorite sent dust into the atmosphere Blocked out the sun and prevented photosynthesis Plants died through lack of light Herbivores then carnivores died through lack of food (collapse of the food chain) Chimpanzees