Skip to main content
Ch. 50 - Behavioral Ecology
Chapter 49, Problem 3

A behavior is considered adaptive if it increases an individual's fitness. How is fitness measured? Select True or False for each statement. T/F strength T/F body size T/F speed T/F number of viable offspring

Verified step by step guidance
1
Understand the concept of fitness in biological terms: Fitness refers to an individual's genetic contribution to the next generation, often measured by the number of viable offspring that survive to reproduce.
Evaluate the statements based on the definition of fitness: Fitness is not directly measured by physical attributes like strength, body size, or speed, but rather by reproductive success.
Analyze the first statement - strength: Strength might contribute indirectly to fitness if it helps in survival or reproduction, but it is not a direct measure of fitness. Therefore, the statement is False.
Analyze the second statement - body size: Similar to strength, body size might indirectly influence fitness but is not a direct measure of fitness. Thus, the statement is False.
Analyze the third and fourth statements - speed and number of viable offspring: Speed, like strength and body size, might indirectly affect fitness but is not a direct measure. The statement is False. The number of viable offspring is a direct measure of fitness, so this statement is True.

Verified Solution

Video duration:
3m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Fitness in Evolutionary Biology

Fitness in evolutionary biology refers to an organism's ability to survive and reproduce in its environment. It is often quantified by the number of viable offspring an individual produces, which contributes to the gene pool of the next generation. Higher fitness indicates a greater likelihood of passing on genes, thus influencing evolutionary processes.
Recommended video:
02:45
History of Evolutionary Theory Example 1

Measuring Fitness

Fitness can be measured through various metrics, primarily focusing on reproductive success. While traits like strength, body size, and speed may influence an individual's ability to survive and reproduce, they do not directly measure fitness. The most direct measure of fitness is the number of viable offspring produced, as it reflects successful reproduction.
Recommended video:
Guided course
03:11
Adaptation Improves Fitness

Adaptive Behaviors

Adaptive behaviors are actions or traits that enhance an organism's fitness by improving its chances of survival and reproduction. These behaviors can evolve over time through natural selection, as individuals exhibiting advantageous traits are more likely to thrive and pass those traits to their offspring, thereby shaping the species' evolutionary trajectory.
Recommended video:
Related Practice
Textbook Question

What do proximate explanations of behavior focus on? a. how displays and other types of behavior have changed through time, or evolved b. the 'adaptive significance' of a behavior c. genetic, neurological, and hormonal mechanisms of behavior d. appropriate experimental methods when studying behavior

623
views
Open Question

Many insects, birds, and other animals are attracted to artificial lights, a side effect of their innate navigational strategies. For example, many birds fly off-course toward bright urban areas during their fall and spring migrations, causing bird mortality due to window strikes and exhaustion. Pose one solution that could reduce impacts on animals and also benefit humans.

83
views
Textbook Question

What do ultimate explanations of behavior focus on?

468
views
Textbook Question

Why does altruism seem paradoxical? a. Sometimes altruistic behavior is actually selfish. b. Altruism does not actually help others. c. Alleles that cause an organism to behave altruistically should be selected against since these alleles should lower the organism's fitness. d. Animals behave altruistically to help the species, but sometimes their behavior harms the species.

644
views
Textbook Question

Is it true that all organisms forage optimally? Why or why not?

397
views
Textbook Question

The male cuttlefish in the chapter-opening photo can rapidly change their skin colors (under nerve control) to flash warning patterns to rivals. Predict the proximate and ultimate causes of this behavior.

316
views