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Evolution by Natural Selection, 5, 4, 3, 2, 1, 6, 7 - Coggle Diagram
Evolution by Natural Selection
Natural Selection
organisms that are best adapted survive
VASRP
natural selection is dependent on...
Heritable traits
advantageous
environment
defined as
differential reproduction of inheritable variants
survival of the "fittest"
organisms that are best adapted survive
best characteristics survive
process, which random evolutionary change is selected by nature
consistent, orderly, non-random way
pressure that causes organisms to change
physically
behavioural
present-day organisms developed from past organisms
eliminates non-favourable traits organisms possess
sub branches of natural selection
sexual selection
one of the several key concepts of evolution
constant influence of evolution within a population
https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/a/darwin-evolution-natural-selection
Variation
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within a population
traits are inherited
inherited from parents
50 percent from mother and 50% from father
traits can be beneficial or non-beneficial
avoiding predation
Exposure to preadators
a difference in organisms
physical
E.g. Body size or hair colour
behavioural
E.g. attracting mates
Stabilizing selection
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majority of population is "normal"
common within the population
some "outliers"
not common
directional selection
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Trait is common
caused by trait being more favourable
E.g. Large size is better than small
diversifying selection
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both traits are desirable
Predator- prey
variation is developed to avoid predation
Adaptation
Adaptations are developed
adaptations help organisms survive
certain adaptations are more advantageous over others
favourable traits increase chance of survival
Non-favourable traits decrease chance of survival
traits are favoured in certain environments and resource
Environmental pressures
change in environmet
changing resources
increased competition
predation
encourage faster development of adaptations
mutation
occurs at low rate
random genetic drift
from one generation to another
process of pure chance
not advantageous
filtered out by natural selection
may be advantageous
organisms that struggle
allow for adaptation
have little use to organisms/ population with small numbers
trait give higher chance of surviving
Selection/survival
Survival of the "fittest"
individuals best suited for their environment
more likely to survive
more likely to reproduce
organisms that make live to reproduce
traits that allow for survival
increase in future generation
increase competition
traits may suit one environment, not another
which genes individuals carry
struggle for resources
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competition for survival
fittest survive
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https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/a/darwin-evolution-natural-selection
Selection occurs because of differences
fertility rates
rate of development
mating success
other aspects of the life cycle
genetic drift
occurs in all population
frequencies of a population change over generation
founder effect
small group of population
split from main population
establish new colony
isolated from original population
doesn't represent full diversity of original populations
similar to bottleneck
different mechanism
colonization rather than catastrophe)
https://commons.wikimedia.org/wiki/File:Founder_effect.png
bottle neck effect
natural disaster
dramatic reduction of population
leave small and random assortment of survivors
E.g. earthquake, flood, fire
https://cnx.org/contents/yNlSxj0E@5/Population-Genetics
does not depend on beneficial or harmful effects
SCIENCE ESSENTIALS 10 FOR NSW S Stage 5
Reproduction
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surviving population reproduce
heritable traits
traits that can be inherited by offspring
Less favourable genes
less likely to be inherited by offsping
favourable genes
likely to be inherited by offspring
likely to continue passing the gene
https://www.khanacademy.org/science/ap-biology/natural-selection/natural-selection-ap/a/darwin-evolution-natural-selection
mutation may occur
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Organisms reproduce more than environment can sustain
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example
rock lobsters release 300,000 eggs
only 30 eggs survive to reproduce
characteristics best suited will survive, reproduce and pass their characteristics to offspring
measure of reproductive efficiency of traits
relative fitness
relative probability of inheritable traits inheriability
Population change over time
over time
generations of populations characteristic change
favourable traits become common
lead to improvement
in survival
in continuation of species
population will become adapted to its environment
less favourable traits
likely to die out
likely to be less common
https://biologydictionary.net/natural-selection/
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