Micro Evolution
Micro Evolution can be defined as changes within one species.
What is Micro Evolution?
How does it work?
Micro evolution works by inbreeding of the same species of animals. this is seen today example, with dogs. Dogs have descended from wolves and are able to breed between very diverse breeds. This occurs all over the world with animals that are in the same species. Some of the mechanisms for this is natural selection, genetic drift, non-random mating, gene flow and mutations. The main man involved in micro evolution is Charles Darwin who studied the Galapagos finches for five years on the HMS Beagle. |
The main mechanisms of Micro Evolution, ways to change the gene pool:
1 Natural Selection
Natural selection is the species that is best suited to it's environment, is able to adapt to it's environment, and pass their genes to the next generation.
4 Gene Flow
Gene flow can be defined as the transfer of specific genes from one population to another. It is this mechanism that introduces the variations into a new population. An example might be a mutation. If the gene flow is restricted in any way, then the populations that were once joined, will now change independently.
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2 Genetic drift
Genetic drift can be described as a random change in the gene pool, by chance.
5 Mutation
Mutation is the change in DNA of a specific organism. If a mutation is favourable then it can be passed on to future generations, this creates change in the gene pool.
Mutations cause high variability, Mutations are essential for adapting to our environment. When a population has a high variability it is more able to deal with external factors. |
3 Non- Random Mating
Non-Random mating can be defined as organisms that are specific about choosing it's mate. Examples of Non- Random mating is:
Harems- which is described as one male mating with many females. Assortative mating- which is described as choosing a mate with similar characteristics as yourself. Sexual selection- which happens when a mate is chosen by a criteria ex. Display, song, size, colour, territory, etc. |
Types of Selection
Directional Selection- Is the process by which extreme variations are favored over the average pulling the population to one side. One phenotype is favored over the other.
Diversifying Selection- Is the process by which extreme variations are favored over the intermediate forms. Causing the intermediate forms to drop while the extremes spike. Stabilizing Selection- Is the process by which the intermediate populating thrives over the extremes causing the Genetic diversity to decrease. |