📚 Topic Summary
Natural selection is the process where organisms with traits that help them survive and reproduce in a particular environment leave more offspring than individuals without those traits. This leads to these advantageous traits becoming more common in a population over time. Two key components are variation (differences in traits within a population) and heritability (the ability of those traits to be passed down from parents to offspring). Without both, natural selection cannot occur. Variation provides the 'raw material' for selection, and heritability ensures that successful traits are inherited.
🧪 Part A: Vocabulary
Match the following terms with their correct definitions:
| Term |
Definition |
| 1. Variation |
a. The process where organisms with advantageous traits survive and reproduce more successfully. |
| 2. Heritability |
b. Differences in traits within a population. |
| 3. Natural Selection |
c. A change in the genetic composition of a population over time. |
| 4. Adaptation |
d. The ability of a trait to be passed from parent to offspring. |
| 5. Evolution |
e. A trait that enhances an organism's survival and reproduction in a specific environment. |
🧬 Part B: Fill in the Blanks
Complete the paragraph below using the following words: environment, offspring, traits, survival, heritable.
Natural selection occurs when individuals with certain _________ are better suited to their ___________. These individuals have a higher chance of _________ and reproduction, leading to more _________ with those same, _________ traits in the next generation.
🤔 Part C: Critical Thinking
Imagine a population of birds where beak size varies. Some birds have small beaks, and some have large beaks. If the only food source available becomes hard seeds, how might natural selection act on this population? Explain your reasoning.