Heritable genetic variation in a population is an essential prerequisite for which of the following long term biological processes?

Introduction / Context:
Evolution involves changes in the genetic makeup of populations across many generations. For natural selection and other evolutionary mechanisms to act, there must be differences among individuals that can be passed from parents to offspring. This question checks whether you can correctly connect the idea of heritable variation with the biological process that depends on it most directly.

Given Data / Assumptions:

• Heritable variation refers to genetic differences that can be passed to offspring.
• Options include evolution, asexual reproduction, mitosis, meiosis, and short term regulation.
• We are focusing on long term changes in populations, not immediate changes in individuals.
• Basic understanding of Darwinian evolution and inheritance is assumed.

Concept / Approach:
Evolution by natural selection requires three key conditions: variation among individuals, heritability of that variation, and differential reproductive success. If all individuals were genetically identical and no variation could be inherited, then even if some individuals survived better due to chance, there would be no consistent change in the population's gene pool over time. Asexual reproduction, mitosis, and meiosis can occur in the absence of significant heritable variation; they are cellular processes, not population level changes. Short term physiological regulation, like adjusting heart rate or blood sugar, occurs within an individual and does not require heritable variation across a population.

Step-by-Step Solution:
Step 1: Identify what heritable variation means: differences in DNA sequences that can be transmitted from parents to offspring. Step 2: Recall that evolution is a change in the genetic composition of a population over generations. Step 3: Understand that natural selection can only favour or eliminate traits if those traits are heritable. Step 4: Recognise that asexual reproduction, mitosis, and meiosis are mechanisms of reproduction and cell division that can occur even if all individuals were genetically identical. Step 5: Note that short term physiological adjustments, such as sweating in response to heat, are not inherited traits but individual responses. Step 6: Conclude that the process that specifically requires heritable variation is the evolution of populations over generations.

Verification / Alternative check:
Evolutionary biology texts describe natural selection as acting on phenotypic variation that has a genetic basis. They emphasise that if variation is purely environmental and not heritable, it will not lead to evolutionary change because offspring will not resemble the selected parents in the relevant traits. Conversely, even if meiosis introduces variation through crossing over and independent assortment, the definition of evolution focuses on cumulative changes in populations, confirming that evolution is the process that requires heritable variation.

Why Other Options Are Wrong:
Asexual reproduction in a single individual: This can simply produce genetically identical offspring (clones) with no need for pre existing variation in the population. Mitosis in somatic (body) cells: Mitosis copies genetic material for growth and repair within an individual and does not depend on population level variation. Meiosis as a cell division process: Meiosis helps generate variation but does not itself require it; it can occur in genetically uniform populations as a mechanism. Short term physiological regulation in an individual: These responses are not inherited changes in DNA and do not involve population level genetic variation.

Common Pitfalls:
Students sometimes confuse the source of variation (like meiosis and mutation) with the process that uses that variation (evolution). Another pitfall is to think that any process involving cells or reproduction must require heritable variation. To avoid this, remember that evolution is defined at the population and generational level, whereas mitosis, meiosis, and asexual reproduction are cellular or individual level events.

Final Answer:
Heritable variation is required for the evolution of populations over generations.