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How can the process of evolution by natural selection be modelled? :fish: …
How can the process of evolution by natural selection be modelled?
:fish: :rewind: :shark:
What is evolution by natural selection?
Struggle for survival due to selection pressures
Individual with advantageous trait help it to survive
More likely to survive in environment to reach sexual maturity
Majority of the offspring will inherit beneficial traits
This increases the frequency of this trait
Eventually, a new [adapted] species will be formed
The individuals without these beneficial traits will die out
Have no descendants (offspring)
Less individuals with disadvantageous trait
Less chance of extinction for species
Can be modelled/shown through VASRP structure
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Explain why natural selection is important for populations?
Helps organisms to make current selection pressure less of a risk
Examples
For example, gives organisms a greater access to food
Gives organisms less of a risk of being eaten by predators
Gives organisms a greater chance of survival in their environment
Explain the effects of natural selection on populations?
More likely to inherit beneficial adaptation over time
Able to be less affected by selection pressures
Helps population become better adapted to selection pressures
What are some examples of natural selection that the model could possibly be based off?
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Peppered moths
Variation
Individual's variation = different colour pigmentation gene (black or white)
Adaptation
Tree trunks were white; after industrial revolution, trees turned black
Survival/Selection
Black trees gave black moths a survival advantage
Harder to see by predators
Reproduction
Individuals with variation would survive longer
More likely reach sexual maturity
The advantageous variation more likely to be passed down to offspring
Population changes over time
The frequency of this trait will increase; helps individuals to survive
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Giant Tortoises on the Galapagos Islad
Variation
Individual's variation = different sized neck and different shaped shell
Adaptation
Humid environment = food source on the ground
Direr environment = food source higher up
Survival/Selection
Different environments cater better for different variations
Due to better access to food
Reproduction
Individuals with variation would survive longer
More likely reach sexual maturity
The advantageous variation more likely to be passed down to offspring
Population changes over time
The frequency of this beneficial traits will increase; helps individuals to survive
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Giraffes
Variation
Individual's variation = longer necks
Adaptation
Food (leaves) where high up in trees
Survival/Selection
Individuals with variation are able to reach leaves on high trees
Reproduction
Individuals with variation would survive longer
More likely reach sexual maturity
The advantageous variation more likely to be passed down to offspring
Population changes over time
The frequency of this trait will increase; helps individuals to survive
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Galapagos finches
Variation
Individual's variation = different beck shape and size
Adaptation
Different islands had different food available
Examples
Hard nuts
Fruits
Big fruits
Survival/Selection
Different islands cater for different variations
Due to better access to food
Reproduction
Individuals with variation would survive longer
More likely reach sexual maturity
The advantageous variation more likely to be passed down to offspring
Population changes over time
The frequency of this beneficial traits will increase; helps individuals to survive
What are the key features of evolution by natural selection?
There are selection pressures affecting the population
Access to resources
Food
Shelter
Territory
Mates
Environmental factors
Temperature
Weather conditions
Vulnerability to diseases
Human activities
Hunting
Pollution
Variation between organisms
hunting by predators
There are selection pressures
There is a struggle for survival
Some variations help organisms survive
The frequency a trait will increase
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Helps organisms survive and reproduce
Advantageous variations = more likely to be passed on to offspring
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Organisms with less favourable characteristics die out
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Don’t have an opportunity to reproduce
John Gould 1845
D.Cavagnaro & M.Cavagnaro (n.d)
