Natural Selection Graphs Flashcards

Questions and Answers

What is stabilizing selection?

Natural selection in which the average form of a trait is favored (correct)

Natural selection that eliminates extremes in a population

Natural selection that favors individuals with either extreme form of a trait

Natural selection that favors one extreme form of a trait

What characterizes directional selection?

Natural selection that favors the average form of a trait

Natural selection that favors one extreme form of a trait (correct)

Natural selection that eliminates the average form of a trait

Natural selection that favors either extreme form of a trait

What is disruptive selection?

Natural selection that favors the average form of a trait

Natural selection that eliminates all traits

Natural selection that favors individuals with either extreme form of a trait (correct)

Natural selection that results in a stable population

Give an example of stabilizing selection.

Birds usually laying 4 eggs to avoid starving or losing all offspring. Signup and view all the answers

Provide an example of directional selection.

When pollution made trees darker, leading to darker moths surviving better. Signup and view all the answers

What is an example of disruptive selection?

Birds with very large beaks and small beaks thrive at the expense of medium beaks. Signup and view all the answers

Study Notes

Selection Types in Natural Selection

Stabilizing Selection: Favors the average form of a trait, leading to increased frequency of this trait in the population.
Directional Selection: Favors one extreme of a trait, resulting in a shift in the population towards that extreme trait form.
Disruptive Selection: Supports individuals with either extreme form of a trait, potentially leading to a split in the population's traits.

Examples of Natural Selection

Stabilizing Selection Example: Birds typically lay four eggs. Laying too many can lead to starvation, while too few may result in loss of potential offspring due to death of others.
Directional Selection Example: In polluted environments, tree color changed to darker shades, providing better camouflage for darker moths. This led to a rise in the population of darker moths.
Disruptive Selection Example: Birds with large beaks are adapted for cracking larger seeds, while those with small beaks thrive on insects. Birds with medium-sized beaks are less efficient and thus less favored.

Graphical Representation

Stabilizing Selection Graph: Illustrates how the average trait becomes more common over time, with a peak at the average trait value.
Directional Selection Graph: Shows a shift towards one extreme trait in the distribution of a population, emphasizing the favoring of that extreme.
Disruptive Selection Graph: Depicts two peaks at the extremes of trait distribution, indicating a preference for extreme traits over intermediaries.

Description

Test your understanding of natural selection with these flashcards. Each card presents a specific type of selection, including stabilizing, directional, and disruptive selections, along with their definitions. Perfect for mastering evolutionary biology concepts!