Question

A change in one or more characteristics of a population that is heritable and occurs from one generation to the next is called a. natural selection. b. sexual selection. c. population genetics. d. evolution. e. inheritance of acquired characteristics

Short answer

The correct answer is d. Evolution.

Step-by-step solution

Understand the definition

The definition provided describes a scenario where there is a change in population characteristics which is heritable (passed down generations). It is important to understand the main elements of this definition: heritability and generational change.

Match the definition with possible terms

Each term is considered to see whether it matches with the provided definition. Here: a. Natural selection: It could be a possibility, but natural selection does not necessarily imply heritability and occurring from one generation to next, hence it's not the best match. b. Sexual selection: It is a mode of natural selection but do not cover the whole aspect of heritability and change from one generation to the next. c. Population genetics: It studies frequency and interaction of alleles in a population but does not ideally represent the concept being defined. d. Evolution: This term directly relates to the heritable changes in characteristics of a population from one generation to another. e. Inheritance of acquired characteristics: It's a theory that organisms can change during their lifetimes in response to their environment and further pass these changes to their offsprings. But this doesn't fully cover the definition since it focuses on acquired changes, not general changes.

Choose the correct term

Based on the analysis in step 2, the term that best fits the provided definition is 'evolution'.

Key concepts

Natural Selection

Natural selection is a fundamental mechanism of evolution proposed by Charles Darwin. It describes the process by which certain heritable traits become more common in a population over successive generations because they confer a survival or reproductive advantage.
This process involves the differential survival and reproduction of individuals due to differences in phenotype.
- **Heritability:** Traits must be passed down from parents to offspring. - **Variation:** There must be differences within the population's traits. - **Differential Survival:** Some individuals possess traits that increase their chances of survival. - **Adaptation:** Over time these advantageous traits accumulate in the population. Thus, natural selection results in the evolution of organisms that are better adapted to their environment.

Sexual Selection

Sexual selection is a distinct type of natural selection that focuses on an organism's ability to obtain or successfully copulate with a mate.
It can lead to remarkable evolutionary changes, influencing traits related to mating success, rather than directly improving survival. - **Types of Sexual Selection:** - **Mate Choice (Intersexual Selection):** Occurs when individuals of one sex (usually females) are choosy in selecting their mates, often based on specific traits, such as vibrant coloration or elaborate displays. - **Intrasexual Selection:** Involves competition between members of the same sex (usually males) for access to mates which may result in the development of traits like larger size or aggressive behavior. As a result, sexual selection can lead to traits that might not seem beneficial for survival but are advantageous for reproduction.

Population Genetics

Population genetics is the study of how genetic composition of populations changes over time due to different evolutionary processes. It explores how alleles, or different versions of a genetic trait, spread and persist in a population. - **Key Principles:** - **Gene Pool:** The complete set of genetic information in a population. - **Genetic Drift:** Random changes in allele frequencies, which can lead to significant effects in small populations. - **Mutation:** Introduction of new genetic variants into the gene pool. - **Gene Flow:** The transfer of alleles between populations, increasing genetic diversity. - **Selection Pressures:** Can be either natural or sexual, leading to changes in allele frequencies. Through these processes, population genetics provides a robust framework to understand the complexities of evolution and the genetic basis for diversity within and between species.