Biology, gcse aqa B2 6.4
- Created by: Matthew Binks
- Created on: 12-01-13 16:20
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- Biology- isolation and the evolution of new species.
- Isolation and evolution
- If the popualtion gets seperated the conditions are likely to be different, this means different characteristics will be selected to help that population survive
- Any population of a species has gentic variation.
- once the species can no longer interbreed, a new species has been formed.
- How do populations become isolated.
- Geographical isolation- they become physically isolated by a geographical feature. This might be a new mountain range, a new river or land becoming an island.
- When Australia seperated from the rest of the continents 5 million years ago, mammals started to carrry their babies in pouches.
- Geographical isolation- they become physically isolated by a geographical feature. This might be a new mountain range, a new river or land becoming an island.
- Organisms in isolation.
- If organisms are only on one island then they are called endemic to that place.
- Speciation!
- Genetic variation is caused by sexual reproduction and mutation.
- The allels that will be selected are the ones that help the species to survive.
- The alleles selected will change depending on the environment, when a species can no longer interbreed with the old species, speciation has taken place.
- Isolation and evolution
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