Table of Contents
- 1 How does disruptive selection result in two distinct phenotypes?
- 2 In what type of selection are two or more distinct phenotypes advantageous while the intermediate phenotypes are on average less fit?
- 3 What are the 4 types of selection?
- 4 What are the three types of selection?
- 5 How does phenotype affect natural selection?
- 6 How do you explain natural selection?
- 7 When does natural selection favor an average phenotype?
- 8 How does directional selection work on the phenotype?
How does disruptive selection result in two distinct phenotypes?
How does disruptive selection result in 2 distinct phenotypes? If selection pressure is strong enough and tall enough, the curve will split in two and lead to 2 distinct phenotypes. Allele frequencies change as the result of a drop in population size.
In what type of selection are two or more distinct phenotypes advantageous while the intermediate phenotypes are on average less fit?
Diversifying Selection Sometimes two or more distinct phenotypes can each have their advantages and be selected for by natural selection, while the intermediate phenotypes are, on average, less fit. The result of this type of selection is increased genetic variance as the population becomes more diverse.
How does selection act on phenotype?
Natural selection acts on the phenotype (the traits or characteristics) of an individual. On the other hand, natural selection does not act on the underlying genotype (the genetic makeup) of an individual. For many traits, the homozygous genotype, AA, for example, has the same phenotype as the heterozygous Aa genotype.
How can natural selection favor different phenotypes at different times?
How can natural selection favor different phenotypes at different times? Natural selection can only select against phenotypes. If the dominant phenotype is selected for, heterozygous individuals will retain the recessive allele in the population.
What are the 4 types of selection?
There are several ways selection can affect population variation:
- stabilizing selection.
- directional selection.
- diversifying selection.
- frequency-dependent selection.
- sexual selection.
What are the three types of selection?
The 3 Types of Natural Selection
- Stabilizing Selection.
- Directional Selection.
- Disruptive Selection.
What are the 3 natural selection?
Is PP genotype or phenotype?
A simple example to illustrate genotype as distinct from phenotype is the flower colour in pea plants (see Gregor Mendel). There are three available genotypes, PP (homozygous dominant ), Pp (heterozygous), and pp (homozygous recessive).
How does phenotype affect natural selection?
When a phenotype produced by certain alleles helps organisms survive and reproduce better than their peers, natural selection can increase the frequency of the helpful alleles from one generation to the next – that is, it can cause microevolution.
How do you explain natural selection?
Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways. This variation means that some individuals have traits better suited to the environment than others.
What is the most common type of selection?
The most common of the types of natural selection is stabilizing selection. In stabilizing selection, the median phenotype is the one selected for during natural selection.
What is a good example of Intrasexual selection?
Intrasexual selection, on the other hand, occurs between members of the same sex. For example, male sea lions compete for dominance over rookeries of females. Here, intrasexual selection acts on the physiology of the sea lion, to make it large enough to compete with other males for a group of females.
When does natural selection favor an average phenotype?
If natural selection favors an average phenotype, selecting against extreme variation, the population will undergo stabilizing selection (Figure 1). In a mouse population that live in the woods, for example, natural selection is likely to favor mice that best blend in with the forest floor and are less likely for predators to spot.
How does directional selection work on the phenotype?
Directional selection: one end of a phenotypic distribution is favored → shifts the mean phenotype Diversifying selection: favors phenotypes of opposite extremes; disfavors intermediate phenotypes → expands the phenotypic distribution and can lead to 2 peaks in the frequency distribution
How does selection affect variation in a population?
There are several ways selection can affect population variation: stabilizing selection, directional selection, diversifying selection, frequency-dependent selection, and sexual selection.
Which is not a feature of natural selection?
Natural selection is differential survival or reproduction of individuals with different phenotypes High mortality or low reproduction within a population is not natural selection unless it is differential across individuals with different phenotypes [when food is in low supply everyone will suffer; there may not be selection]