Natural Selection and Speciation

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In a population of organisms what happens to produce what?
random mutations produce new alleles
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so therefore what does this cause?
new variation
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therefore what do individuals in populations have?
different genotypes and show genetic variation
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What happens if there is a change in environment?
some genotypes may make organisms more likely to survive long enough to reproduce
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What would they pass on?
particular alleles on to their offspring
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What happens to the other organisms?
the ones less adapted will die from predation, competition for food and disease
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Those that reproduce will have offspring that?
some of which will inherit the favourable alleles in their genotypes
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What will happen over time?
proportion of individuals with favourable genotypes will increase in the population.
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What happens to a group of individuals?
a population somehow get separated and reproductively isolated from the rest of the population so they cannot breed with them.
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What does each population accumulate?
different random mutations so the different genes pools may contain different alleles.
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Why might the variations be reduced?
some alleles may be lost by genetic drift and genetic diversity may be reduced by inbreeding
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What is each population exposed to?
different selection pressures in their habitats
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What are individuals survive?
genotypes that enable them to survive to breed will pass their alleles on to the next generation
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What does it change?
frequencies of a particular allele
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What happens over time?
results in individuals in each population becoming specifically adapted to their new environments
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What happens when individuals have changed so much?
they can no longer interbreed successfully, changes in breeding behaviour, timing of breeding etc
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Other cards in this set

Card 2

Front

so therefore what does this cause?

Back

new variation

Card 3

Front

therefore what do individuals in populations have?

Back

Preview of the front of card 3

Card 4

Front

What happens if there is a change in environment?

Back

Preview of the front of card 4

Card 5

Front

What would they pass on?

Back

Preview of the front of card 5
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