Genetics and Evolution
- Created by: yzannepepper
- Created on: 11-04-18 17:04
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- Genetics and Evolution
- The history of Genetics
- Gregor Mendel
- Analysed different offspring of peas
- relealized some characteristics were more dominant than others
- chromosomes observed under a microscope in late 19th century
- 1950's scientists discovered DNA and genetics
- led to development of the gene theory
- Theories of evolution
- Jean-Baptiste Lamarck
- suggested that individual animals adapted to suit the environment
- e.g. giraffes have long necks to reach up to slightly longer trees' so each generation has slightly longer necks.
- e.g. giraffes have long necks to reach up to slightly longer trees' so each generation has slightly longer necks.
- suggested that individual animals adapted to suit the environment
- suggested that individual animals adapted to suit the environment
- Charles Darwin
- all living organisms evolved from simpler life forms
- survival of the fittest
- they pass on the survival characteristics to the next generation
- Jean-Baptiste Lamarck
- Accepting Darwin's ideas
- evidence
- organisms on different islands had adapted by natural selection
- breeding experiments with pigeons
- objections
- challenged God and ethical objections
- not enough evidence
- no way to explain how inheritance happened at this time.
- evidence
- Evolution and speciation
- Alfred Russel Wallace
- if species existed in various forms, those which were poorly adapted were likely to die out
- warning colouration on animals
- Speciation
- wide range of alleles from genetic variations - that will result from sexual reproduction and mutation = genetic variation
- where the populations become so different that successful interbreeding is no longer possible
- Alfred Russel Wallace
- Evidence for evolution
- fossils
- fossils can give us a clear insight to what an animal looked like
- extract DNA and compare to modern DNA
- many animals that are extinct can prove presence
- however fossils are not always complete
- many fossils still to be found
- many organisms died that didn't fossilise
- little fossil trace of some soft-bodied organisms
- fossils
- antibiotic resistant bacteria
- MRSA (staphylococcus aureus) due to natural selection was not affected by antibiotics
- important not to overuse antibiotic resistant bacteria
- important otofinish course of medicine
- restrict agricultural use of antibiotics
- Video Clip :
- The history of Genetics
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