What are Examples of Natural Selection?

📚 Quick Study Guide

• 🧬 Natural selection is the process where organisms with traits that enable them to better adapt to their environment tend to survive and reproduce more than others.
• 🌱 Key factors driving natural selection include: variation, inheritance, high rate of population growth, and differential survival and reproduction.
• 🐦 Adaptations are traits that enhance survival and reproduction in a specific environment. Examples include camouflage, mimicry, and resistance to diseases.
• ⏱️ Natural selection acts on phenotypes (observable characteristics), which are influenced by genotypes (genetic makeup).
• 🌍 The environment plays a crucial role; changes in the environment can lead to different traits becoming advantageous.
• 🐞 Evolution is the change in the heritable characteristics of biological populations over successive generations. Natural selection is a primary mechanism of evolution.
• 📊 Mathematical representations can help understand selection. For example, fitness ($w$) measures reproductive success.

🧪 Practice Quiz

1. Which of the following is the MOST accurate definition of natural selection?
   1. A) Random changes in the genetic makeup of a population.
   2. B) The process by which organisms with certain inherited traits survive and reproduce better than others.
   3. C) The development of new species through geographic isolation.
   4. D) The intentional breeding of animals and plants by humans.
2. A population of beetles has varying colors, from light brown to dark brown. Birds prey on the lighter-colored beetles more easily. Over time, what is MOST likely to happen?
   1. A) The population will become entirely light brown.
   2. B) The population will become entirely dark brown.
   3. C) The beetle population will adapt to camouflage with the birds.
   4. D) The beetle population will develop wings to fly away from the birds.
3. Antibiotic resistance in bacteria is an example of natural selection. Why is this the case?
   1. A) Bacteria intentionally mutate to become resistant to antibiotics.
   2. B) Antibiotics cause mutations in bacteria that lead to resistance.
   3. C) Bacteria with resistance genes survive and reproduce better in the presence of antibiotics.
   4. D) Antibiotics provide bacteria with the nutrients they need to develop resistance.
4. What role does variation play in natural selection?
   1. A) It prevents natural selection from occurring.
   2. B) It provides the raw material upon which natural selection can act.
   3. C) It ensures that all individuals in a population are identical.
   4. D) It only affects the physical appearance of organisms.
5. Which of the following is an example of an adaptation?
   1. A) A sudden change in weather patterns.
   2. B) A bird migrating to a warmer climate.
   3. C) A cactus having spines instead of leaves in a desert environment.
   4. D) A person learning a new language.
6. Why is a high rate of population growth important for natural selection to occur?
   1. A) It reduces competition for resources.
   2. B) It increases the likelihood of beneficial mutations arising.
   3. C) It ensures that all individuals will survive and reproduce.
   4. D) It prevents the environment from changing.
7. Industrial melanism, where darker moths became more common during the industrial revolution, is an example of:
   1. A) Genetic drift
   2. B) Artificial selection
   3. C) Natural selection
   4. D) Mutation