Understanding how variations work in a species is essential in biology. This concept explains why certain traits survive and spread, while others, especially disadvantageous ones, often phase out over generations.
1. Understand the Concept of Variation:
- Variation refers to the inherited differences among individuals within the same species. These differences can include physical traits, like color, size, or shape, and behavioral traits, like ways of gathering food or finding shelter.
- Variations happen due to genetic differences, and they play a big role in how well an organism can survive and reproduce in its environment.
2. What Happens to Variations Over Time?:
- Some variations can give certain individuals an advantage. For example, if a rabbit has a thicker coat of fur, it might survive better in cold environments compared to other rabbits.
- Variations that help survival and reproduction are more likely to be passed down to the next generation, because these traits help organisms live longer or reproduce more effectively.
- Over many generations, these helpful variations can spread throughout the population, leading to changes in the species over time. This process is part of evolution.
3. Why Some Variations Don’t Get Passed On:
- Not all variations are helpful. Some might actually make survival or reproduction harder for an individual. For example, if a bird has a slightly deformed wing, it might struggle to fly, making it harder to find food or escape predators.
- Variations that are harmful (that is, they reduce an individual’s reproductive success) are less likely to be passed on, because individuals with those traits might not survive as well or reproduce as much.
- As a result, these disadvantageous traits don’t usually spread throughout the population. Instead, they often disappear over time.
4. Analyze the Statements in the Question:
- Let’s go through each of the statements provided and see if it accurately describes variation:
- Statement 1: “Variations are inherited differences between individuals of the same species.”
This statement is correct. Variations refer to inherited differences, so this does describe variation. - Statement 2: “Variations that decrease reproductive success are more likely to be passed on.”
This is the least likely to be true. Variations that decrease reproductive success usually aren’t passed on as often, because they reduce an individual’s ability to survive and reproduce. - Statement 3: “Variations may result in changes to an entire population after many generations.”
This statement is accurate. Helpful variations can spread across the population over time, leading to population-wide changes. - Statement 4: “Variations provide some individuals with an advantage.”
This statement is also true. Some variations can give certain individuals an advantage in their environment, helping them survive and reproduce.
- Statement 1: “Variations are inherited differences between individuals of the same species.”
5. Identify the Correct Answer:
- Based on the explanations above, Statement 2 is the least likely to describe variation.
- Answer: “Variations that decrease reproductive success are more likely to be passed on” is incorrect because harmful variations typically do not spread through the population.