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Lamarckism
The incorrect theory which suggests that organisms inherit acquired characteristics
Darwinism
Charles Darwin proposed the theory of evolution by natural selection in 1859
Evolution is the change in Species over a long period of time
The mechanism for evolution is natural selection
Fitness
Is measured by the proportion of fertile offspring left by a specific phenotype
...
, deliberately breed organisms that have desirable
characteristics (phenotypes)
...
The most successful
phenotypes (stronger) have a greater likelihood of reproducing in greater frequencies than other
less favoured phenotypes and allele frequency changes over time
...
The best way to recall the process of Natural Selection is by using VCSRI
Variation
o Exists in a population due to the complex combination of alleles that exist in organisms
within a population
...
o The combination of alleles gives rise to phenotypes that will have variable favourability
to certain environments
Competition
o Competition exists within and between organisms of different species for precious
resources (shelter, H20, food, mates)
...
This reduction in the variety of alleles present in the population
persists as
Allele Frequencies
Allele frequencies can change over time in a population for a variety of reasons
Example
o Changing selection pressures
o Competition
o Genetic drift
o Bottlenecks
The Hardy Weinberg equilibrium (or principle can be used to monitor changed in a population)
If you monitor the allele frequencies in a population over time you can establish if the allele
frequency is changing and how fast it is changing if the change is rapid then you can start to focus on
changing selection pressures that may be causing this
...
If there is a sudden change in allele
frequencies at the same time as a change in the environment then you have very solid data to
support the argument that a specific selection pressure is directly impacting on studied species in
the area/ecosystem