Natural selection
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NATURAL SELECTION. The scientifically identified method explaining how evolution happens. My Students Are Comedians. Types of Selection Processes. What is a population? What would be some pressures that could develop upon a population? With such pressures what could happen to a population?

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NATURAL SELECTION

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Natural selection

NATURAL SELECTION

The scientifically identified method explaining how evolution happens.


My students are comedians

My Students Are Comedians


Types of selection processes

Types of Selection Processes

What is a population?

What would be some pressures that could develop upon a population?

With such pressures what could happen to a population?

What is Artificial Selection?

Natural Selection is based upon natural pressures to a population.


Stabilizing selection

Stabilizing Selection


Disruptive selection

Disruptive Selection


Directional selection

Directional Selection


Frequency dependent selection

Frequency-Dependent Selection

In positive frequency-dependent selection, the fitness of a phenotype increases as it becomes more common.

In negative frequency-dependent selection, the fitness of a phenotype increases as it becomes rarer. This is an example of balancing selection.


Example

Example

Natural selection may favor non-poisonous butterflies that have the same color pattern as poisonous butterflies. This system is called Batesian mimicry.


Sexual selection

Sexual Selection

By making themselves attractive to the opposite sex (intersexual selection, between the sexes).

By intimidating, deterring or defeating same-sex rivals (intrasexual selection, within a given sex).


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