Question

In evolutionary theory, __________ refers to the reproductive success of an individual organism relative to the average reproductive success in the population. A. natural selection B. gene flow C. adaptation D. fitness

Short answer

Answer: Fitness

Step-by-step solution

Define the terms.

Begin by defining the given terms in the context of evolutionary theory: A. Natural selection: A process in which individuals with certain inherited traits are more likely to survive and reproduce than others. B. Gene flow: The movement of genes from one population to another, often due to migration. C. Adaptation: A characteristic that helps an organism survive and reproduce in its environment. D. Fitness: A measure of an organism's reproductive success, often relative to the average reproductive success in the population.

Identify the correct term.

Now that we have the definitions laid out, we can see that the term that refers to the reproductive success of an individual organism relative to the average reproductive success in the population is "fitness" (option D).

Provide the answer.

The correct answer to the exercise is D. Fitness.

Key concepts

natural selection

In evolutionary theory, natural selection is one of the key mechanisms that drives evolution. It revolves around the idea that individuals within a population have variations in their traits. These traits may either be beneficial, neutral, or detrimental to their survival and reproductive success.

When environmental pressures favor individuals with particular traits, these individuals are more likely to survive and pass on their traits to the next generation. This leads to a gradual change in the population over time.

• Beneficial traits become more common.
• Detrimental traits may decrease in frequency.

Thus, natural selection leads to the evolution of a population better suited to its environment, reinforcing the concept of "survival of the fittest."

gene flow

Gene flow refers to the movement of genes or alleles between populations. This movement usually occurs through migration, when individuals from one population travel to a different one and mix their genetic information.

This can have several important implications for the genetic makeup of a population:

• Increases genetic diversity and reduces the chance of interbreeding.
• Helps prevent populations from becoming too genetically distinct.
• Can introduce advantageous or disadvantageous traits.

Overall, gene flow is crucial for maintaining genetic diversity and facilitating adaptation to changing environments.

adaptation

Adaptation in evolutionary terms refers to a trait or set of traits that have developed over time, allowing an organism to thrive in its particular environment. These traits improve the organism's chances of survival and reproduction in its habitat.

Adaptations can be structural, behavioral, or physiological:

• **Structural adaptations** refer to physical features such as the beaks of birds or the fur of mammals that aid in survival.
• **Behavioral adaptations** are actions organisms take to survive, like migration patterns or mating rituals.
• **Physiological adaptations** include internal functions, like the ability of some animals to retain water in desert climates.

Through the process of natural selection, these adaptations are refined over generations, allowing organisms to better exploit their environments.

fitness

Fitness, in the realm of evolutionary biology, refers to the reproductive success of an organism relative to others in the population. It is not merely about survival but about the ability to pass genes to the next generation effectively.

Fitness is influenced by factors such as the number of offspring produced, the ability of those offspring to survive, and the reproductive lifespan of the organism. The higher the fitness, the greater the organism's representation in the gene pool of future generations.

• High fitness means effectively passing genes to the next generation.
• Low fitness results in fewer offspring or less viable offspring.

An organism's fitness is ultimately determined by how well it adapts to and can reproduce in its environmental conditions.