Which of the following describes directional selection?

Directional selection occurs when phenotypes at both extremes of the phenotypic distribution are selected against.

What is directional selection quizlet?

directional selection. Natural selection in which individuals at one end of the phenotypic range survive and reproduce more successfully than do other individuals.

Which of the following is an example of directional natural selection quizlet?

Longer tails in dragonflies and finches for a particular beak size are examples of directional selection, which decreases genetic variation. Natural selection against heavy and light field mice is an example of stabilizing selection, which reduces genetic variation.) You just studied 25 terms!

What are the three types of directional selection?

The 3 Types of Natural Selection
  • Stabilizing Selection.
  • Directional Selection.
  • Disruptive Selection.

What is an example of a disruptive selection?

Disruptive Selection Examples: Color

Light-colored oysters would blend into the rocks in the shallows, and the darkest would blend better into the shadows. The ones in the intermediate range would show up against either backdrop, offering those oysters no advantage and make them easier prey.

Which of the following does directional selection Favour?

The directional selection theory says that an extreme phenotype (characteristics or traits) is favored over other phenotypes and this causes the allele frequency (how often the variant of a gene shows up in a population) to shift over time in favor of the extreme phenotype.

What is directional selection and disruptive selection?

directional selection: a mode of natural selection in which a single phenotype is favored, causing the allele frequency to continuously shift in one direction. disruptive selection: (or diversifying selection) a mode of natural selection in which extreme values for a trait are favored over intermediate values.

What do directional selection and disruptive selection have in common?

Similarities Between Directional and Disruptive Selection

Directional and disruptive selection are two types of natural selection mechanisms. They are responsible for the selection of a particular phenotype over successive generations. Both increase the allele frequency of the favored phenotypes within the population.

What is directional selection in animals?

Directional selection is a type of natural selection in which the phenotype (the observable characteristics) of the species tends toward one extreme rather the mean phenotype or the opposite extreme phenotype.

What is correct for directional natural selection?

Directional selection is one type of natural selection in which the phenotype (the observable characteristics) of the species tends toward one extreme rather the mean phenotype or the opposite extreme phenotype. Hence, the correct answer is ‘shifts allele frequency in a steady, consistent direction

What is an example of stabilizing selection?

In humans, birth weight is an example of stabilizing selection. Babies that are born too small can lose heat too easily and may die, whereas babies being born too large can lead to complications during childbirth and the death of the mother or the baby.

What happens to the mean in directional selection?

Stabilizing selection reduces the amount of variation in a trait.

Which of the following is a situation in which directional selection may be observed?

Which of the following is a situation in which directional selection may be observed? A new allele, which promotes higher fitness in organisms that carry it, is introduced in a population (for example, by a random mutation).

How does disruptive selection occur?

Disruptive selection occurs when individuals of intermediate phenotype are less fit than those of both higher and lower phenotype, such that extremes are favored. This may occur if there are two diverse food sources or predators with diverse preferences for, say, size of prey.

What is directional selection and what are some possible causes for it?

Directional selection occurs when individuals homozygous for one allele have a fitness greater than that of individuals with other genotypes and individuals homozygous for the other allele have a fitness less than that of individuals with other genotypes.

What is selection example?

The definition of a selection is a person or thing that’s been picked or are available to pick. An example of a selection is a cat chosen from a litter of kittens. An example of a selection is a litter of kittens to choose from at the humane society.

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.

Who came up with directional selection?

Charles Darwin’s
Charles Darwin’s Origin of Species, directional selection, and the evolutionary sciences today.

What is the difference between directional and stabilizing selection?

Stabilizing selection (left column) acts against phenotypes at both extremes of the distribution, favouring the multiplication of intermediate phenotypes. Directional selection (centre column) acts against only one extreme of phenotypes, causing a shift in distribution toward the other extreme.

Which type of selection is most common?

stabilizing 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.