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Directional evolution is where one allele is selected in a population over another allele. Imagine a certain breed of dog that live in cold weather, they will have genes for thick fur (allele A), they are still caring allele for thin fur (allele a), but its recessive and animals with thin fur often dont make it. So if you looked at a distrubition in a population of these animals you would see a preponderance for A alleles and very low level of a alleles. Now imagine that over time their habitat changed and they no longer need the thick fur, in fact its detrimental to the animal to have thick fur. You would see a allele distribution shift from most animals having genes A to genes a. Even if a is recessive to A, if all the animals with thick fur die out then only those with thin fur can survive.
Wiki User
∙ 11y ago
Wiki User
∙ 10y agowell I'm not sure if this is right but in my book it say: the environment controls the direction taken by natural selection. When the environment changes different traits may become advantageous.
i found this in my bio book in chapter 11.6 but you should also check out 11.5 to
hope this helps
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What are the three patterns of of natural selection?
directional selection,stabilizing selection, anddisruptiveselection
What type of selection is this?
directional selection
How is natural selection and evolution linked?
Natural selection is one of the 'guiding' principles of evolution.
Describe how natural selection is related to organic evolution?
Organic evolution is the process by which the genetic makeup of a species changes over time. There are several mechanisms by which this can happen: natural selection, genetic drift (chance), migration and mutation. So natural selection is one possible way in which evolution can take place. Most biologists agree that natural selection is the most important mechanism of evolution. This mechanism was first discovered by Charles Darwin and, independently. by Alfred Wallace.
The type of selection in which individuals at one end of a curve have the highest fitness is called?
Disruptive selection
How are evolution and natural selection related?
Natural selection is one of the mechanisms that shapes adaptation and enables evolution.
What are the three patterns of of natural selection?
directional selection,stabilizing selection, anddisruptiveselection
What type of selection is this?
directional selection
What selection favors organisms with phenotypes that are at one extreme rlative to the average phenotype?
Tends to result in a population whose individuals have extreme traits is what? ----> it is directional selection
In a population of horses an extreme phenotype is favored and the distribution of genes in that population shifts toward that phenotype What is the process called?
directional selection
What is natural selection most closely related to?
Natural selection is most closely related to Darwin's theory of evolution.
What is the primary directing force in evolution?
Answer 1The most important directional "force" in evolution is natural selection, or differential reproductive success.Under natural selection I include sexual selection. Note that other people may list these two forms of selection under separate headers. Sexual selection is when organisms display preferences for mates with specific attributes, such as a colourful plumage, or broad hips and large mammaries.
What are the three types of evolution?
1. Directional selection 2. Disruptive selection 3. Stabilizing selection If you need to know more about them then just research. Trust me, it's easier to look it up than it is to ask the question.
Is evolution directional?
No, evolution is not directional as the definition is; the change in allele frequency over time in a population of organisms. Google barnacle to see that evolution has no particular direction, but the adaption of the organism to the immediate environment.
When individuals at only one end of a bell shaped curve of phenotype frequencies have high fitness the results is?
Directional Selection.
What kind of natural Selection would eliminate one extreme?
Directional selection
What do stabilizing selection directional selection have in common?
They both decrease genetic variation .
