Question

scenario #2: there are two types of beetles. beetles that are green in color and beetles that are brown in color. these beetles predominantly live in trees, feeding on leaves. these beetles are the main food source of birds, which feed on the beetles that are easier to see on the green leaves. each spring when the beetles reproduce, they have about 50 babies but only 5 of these 50 ever become old enough to reproduce.
what is the heritable variation in this population? what is the overproduction in this population?
what is the trait that is being selected for? what is the selective pressure in this example? selected against?
make a prediction: how will the population evolve overtime?

Explanation:

• Heritable variation: Color (green and brown) as it is passed down through generations.
• Overproduction: Each beetle pair has about 50 babies but only 5 reach reproductive age.
• Trait selected for: Green color as green - colored beetles are less visible on green leaves.
• Trait selected against: Brown color as brown - colored beetles are more visible and eaten by birds.
• Selective pressure: Predation by birds.
• Prediction: The proportion of green - colored beetles in the population will increase over time as they have a higher survival rate and more chances to reproduce.

Answer:

• What is the heritable variation in this population? Color (green and brown).
• What is the overproduction in this population? Each beetle pair has 50 babies but only 5 reproduce.
• What is the trait that is being selected for? Green color.
• What is the trait that is being selected against? Brown color.
• What is the selective pressure in this example? Predation by birds.
• Make a Prediction: How will the population evolve overtime? The proportion of green - colored beetles will increase.