Natural Selection Graphs Flashcards

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!