Microevolution

Created: Friday, 22 July 2011 09:14 | Published: Friday, 22 July 2011 09:14 | Written by Super User | Print | Email

How does the microevolution occur?

Microevolution is a change in gene frequency within a population over time. This change depends on mutation, natural selection, artificial selection, gene flow and genetic drift. It is totally different from macroevolution and a reductionist as well as holistic account.

Definition:
• A change in gene frequency within a population is known as microevolution

Difference between Microevolution & Macroevolution

Microevolution:
•    adaptations and changes within a species
•    plainly observable throughout nature

Macroevolution:
•    Addition of new traits or a transition to a new species.
•    never been observed in science

We can observe the changes of microevolution quickly. The frequency of the gene for pesticide resistance in crop can increase. Natural selection influences this change because of the introduction of new genes by genetic drift.

Examples of Microevolution:

House Sparrow of USA:
House sparrows evolved different characteristics in different locations in USA. Northern USA sparrow’s are with larger-body and can survive in lower temperatures than the southern USA sparrows. This is because of natural selection. As the north region has colder weather the can survive easily than the south region species.

micro_evo-3

Based on natural selection bacterial strain's have huge and small populations. In both populations new combinations and mutations are evolved. If these population are exposed to any drug, resistance gene versions can be favored by natural selection. Over the time period of many bacterial generations, it adapts to our defenses, evolving right out from under our attempts to rid ourselves of them.

Detecting Microevolutionary Change

micro_evo-4
The beetle species living on a particular mountaintop share a common gene pool. 80% of the genes in the population are with green color and 20% of the genes are with brown color.

A change in gene frequency can be observed over a period of time with a decrease in green color to 60% and a increase in brown color with 40%.

Mechanisms of Microevolution

Migration, mutation, genetic drift, and natural selection can directly affect the micro evolution. The gene frequency of the population will also be modified.

micro_evo-5
Mutation: Brown genes occurred as a result of the mutation happened to green genes.

micro_evo-6
Migration (or gene flow): Immigration of brown genes and green genes from different population.

micro_evo-7
Genetic drift: After the reproduction of beetles, the off springs will have more brown genes than the green genes.

micro_evo-8
Natural selection: Predators eat the easily visible green gene beetles which will end up with the rise in population of brown gene beetles.

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Reference Links:

Title: Microevolution

How does the microevolution occur? (H1)

Definition: (SH6)

· A change in gene frequency within a population is known as microevolution

Difference between Microevolution & Macroevolution (H2)

Microevolution:

· adaptations and changes within a species

· plainly observable throughout nature

Macroevolution: (SH6)

· Addition of new traits or a transition to a new species.

· never been observed in science

We can observe the changes of microevolution quickly. The frequency of the gene for pesticide resistance in crop can increase. Natural selection influences this change because of the introduction of new genes by genetic drift.

Examples of Microevolution: (H3)

House Sparrow of USA: (SH6)

House sparrows evolved different characteristics in different locations in USA. Northern USA sparrow’s are with larger-body and can survive in lower temperatures than the southern USA sparrows. This is because of natural selection. As the north region has colder weather the can survive easily than the south region species.

House Sparrow

Based on natural selection bacterial strain's have huge and small populations. In both populations new combinations and mutations are evolved. If these population are exposed to any drug, resistance gene versions can be favored by natural selection. Over the time period of many bacterial generations, it adapts to our defenses, evolving right out from under our attempts to rid ourselves of them.

Bacterial Population

Detecting Microevolutionary Change(H4)

The beetle species living on a particular mountaintop share a common gene pool. 80% of the genes in the population are with green color and 20% of the genes are with brown color.

Micro Evolutionary Change

A change in gene frequency can be observed over a period of time with a decrease in green color to 60% and a increase in brown color with 40%.

Mechanisms of Microevolution (H5)

Migration, mutation, genetic drift, and natural selection can directly affect the micro evolution. The gene frequency of the population will also be modified.

Mutation: Brown genes occurred as a result of the mutation happened to green genes.

Mutation

Migration (or gene flow): Immigration of brown genes and green genes from different population.

Migration – Gene Flow

Genetic drift: After the reproduction of beetles, the off springs will have more brown genes than the green genes.

Genetic Drift

Natural selection: Predators eat the easily visible green gene beetles which will end up with the rise in population of brown gene beetles.

Natural Selection

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Topic Description:

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Keywords: Microevolution, evolution, single population, gene pool, gene frequency, Mutation, brown genes, parent generation, predation, Micro evolutionary pattern, allele frequency, sparrows, beetles, offspring, genetic drift, gene flow, Evolution Articles, Biology Tutoring, Biology Help, Biology Articles.

Reference Links:

ü http://en.wikipedia.org/wiki/Microevolution

ü http://evolution.berkeley.edu/evolibrary/article/evo_36

ü http://www.newworldencyclopedia.org/entry/Microevolution

ü http://atheism.about.com/od/evolutionexplained/a/micro_macro.htm

ü http://www.allaboutbirds.org/guide/House_Sparrow/lifehistory

Related Topics:

ü What is Evolution?

ü Evolution and Heredity

ü Evolution and Lamarck

ü Evolution and Darwin

ü Modern synthesis of Evolution