A certain population of birds can have one of three beak lengths: short, medium, or long. Birds with short and long beaks can more easily eat seeds than birds with medium beaks. A scientist studies this population of birds for ten years. Most of the birds at the beginning of the study have medium-sized beaks.

Question

How might natural selection change beak length in this population of birds over time? Move the labels to the boxes on the graph.

Response area with 4 blank spaces

Blank space 1 empty
Blank space 2 empty
Blank space 3 empty
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Answer options with 4 options.

Answer 1

Based on the given information about the population of birds and how their beak lengths affect their ability to eat seeds, here's how natural selection might change beak lengths in this population over time:

1. Short Beak Length – Birds with short beaks can efficiently eat seeds, suggesting they may have a better chance of survival and reproduction.

2. Long Beak Length – Similar to short beak lengths, birds with long beaks also have an advantage when it comes to feeding on seeds.

3. Medium Beak Length – Birds with medium beaks are at a disadvantage, as they struggle more than short and long beaked birds to eat seeds effectively. This may result in a decline in the population of birds with medium beaks.

4. Natural Selection Favors Short and Long Beaks – Over time, as those birds with short and long beaks survive and reproduce more successfully than those with medium beaks, the average beak length in the population may shift towards short and long beak lengths.

So, the labels could be placed in the blank spaces as follows:

• Blank space 1: Short Beak Length
• Blank space 2: Long Beak Length
• Blank space 3: Medium Beak Length
• Blank space 4: Natural Selection Favors Short and Long Beaks

This would represent the transition expected due to natural selection affecting the beak lengths in the bird population over time.