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Assuming a population that has genetic variation and is under the influence of natural selection, place the following events in the order in which they would occur: • Genetic frequencies within the population change. • A change occurs in the population’s environment. • Phenotypic variations shift. • Individuals who are well-adapted leave more offspring than individuals who are poorly adapted. • Individuals who are poorly adapted do not survive at the same rate as individuals who are well adapted. a. 1. A change occurs in the population’s environment. 2\. Individuals who are poorly adapted do not survive at the same rate as individuals who are well adapted. 3\. Individuals who are well-adapted leave more offspring than individuals who are poorly adapted. 4\. Genetic frequencies within the population change. 5\. Phenotypic variations shift. b. 1. A change occurs in the population’s environment. 2\. Genetic frequencies within the population change. 3\. Phenotypic variations shift. 4\. Individuals who are poorly adapted do not survive at the same rate as individuals who are well adapted. 5\. Individuals who are well-adapted leave more offspring than individuals who are poorly adapted. c. 1. Phenotypic variations shift. 2\. A change occurs in the population’s environment. 3\. Genetic frequencies within the population change. 4\. Individuals who are poorly adapted do not survive at the same rate as individuals who are well adapted. 5\. Individuals who are well-adapted leave more offspring than individuals who are poorly adapted. d. 1. Individuals who are well-adapted leave more offspring than individuals who are poorly adapted. 2\. Individuals who are poorly adapted do not survive at the same rate as individuals who are well adapted. 3\. Phenotypic variations shift. 4\. Genetic frequencies within the population change. 5\. A change occurs in the population’s environment.

Step by step solution

01

- Identify Trigger Event

Begin by understanding the sequence of events. Natural selection usually starts with a change in the environment. Thus, the first event must be a change in the population’s environment.

02

- Identify Immediate Consequence

After an environmental change, individuals who are poorly adapted do not survive at the same rate as those who are well adapted. This is the immediate consequence of the environmental change.

03

- Identify Subsequent Consequence

Following the survival discrepancy, well-adapted individuals leave more offspring than poorly adapted individuals.

04

- Genetic Frequency Changes

As those better adapted reproduce more successfully, genetic frequencies within the population change over time.

05

- Phenotypic Variations Shift

Finally, as a result of the genetic frequency changes, phenotypic variations in the population shift to reflect the new genetic makeup.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

genetic variation

Genetic variation refers to the differences in the DNA sequences among individuals within a population. It is essential because it provides the raw material for evolution by natural selection. Genetic variation arises through mutations, genetic recombination during sexual reproduction, and horizontal gene transfer. Some important points include:

• Mutations introduce new genetic variations by altering DNA sequences.
• Sexual reproduction combines genes from two parents, increasing variation.
• Genetic diversity allows populations to adapt to changing environments.

Without genetic variation, a population cannot evolve, as there would be no differences for natural selection to act upon.

environmental change

Environmental changes can trigger the process of natural selection by creating new challenges or altering the resources available to a population. These changes can be natural, such as climate shifts, or influenced by human activities, like pollution. Key points to remember:

• Environmental changes often lead to changes in available resources or conditions.
• Individuals with traits that are better suited to the new conditions will have an advantage.
• Those poorly adapted will struggle to survive and reproduce.

Environmental change is usually the starting point in the sequence of natural selection processes, forcing populations to adapt or face extinction.

phenotypic variation

Phenotypic variation is the observable differences in the characteristics of individuals within a population. These variations are the result of genetic differences and can also be influenced by the environment. Key aspects include:

• Phenotypic traits can include physical attributes like size, color, and shape, as well as behavioral traits.
• Not all phenotypic variations provide an advantage; some may be neutral or disadvantageous.
• Natural selection favors phenotypic variations that enhance survival and reproduction in a given environment.

Over time, as certain traits are favored, the phenotypic makeup of the population will shift to reflect the new advantageous characteristics.

adaptation and survival

Adaptation is the process by which a population becomes better suited to its environment through the gradual accumulation of beneficial traits. Survival is a key component, as it determines which individuals will pass their genes on to the next generation. Important factors include:

• Individuals with traits that enhance survival and reproduction are more likely to pass these traits to offspring.
• Adaptations can be structural, behavioral, or physiological changes that increase fitness.
• Over generations, these adaptive traits become more common in the population.

The more well-adapted individuals leave more offspring, while poorly adapted individuals do not survive at the same rate, leading to changes in genetic frequencies over time.