a fruit fly’s wing width affects how well it flies at different temperatures. flies with smaller wing widths can fly better when it is hot. flies with larger wing widths can fly better when it is cold.
the graphs below describe an isolated population of fruit flies over a time period long enough for natural selection to occur. the graphs show wing width measurements for a representative sample of the population at the start of this period and for another representative sample at the end. at the start of this time period, the fruit flies’ environment changed.
describe how the fruit fly population changed over this time period. use the theory of natural selection to construct a possible explanation for this change.
the average wing width in the population. this suggests that flies with smaller wing widths were likely to survive and reproduce than flies with larger wing widths. this may have occurred because the average temperature in the flies’ environment . after the environment changed, the weather would more frequently be too for flies with smaller wing widths to fly well.

Question

a fruit fly’s wing width affects how well it flies at different temperatures. flies with smaller wing widths can fly better when it is hot. flies with larger wing widths can fly better when it is cold.
the graphs below describe an isolated population of fruit flies over a time period long enough for natural selection to occur. the graphs show wing width measurements for a representative sample of the population at the start of this period and for another representative sample at the end. at the start of this time period, the fruit flies’ environment changed.
describe how the fruit fly population changed over this time period. use the theory of natural selection to construct a possible explanation for this change.
the average wing width  in the population. this suggests that flies with smaller wing widths were  likely to survive and reproduce than flies with larger wing widths. this may have occurred because the average temperature in the flies’ environment . after the environment changed, the weather would more frequently be too  for flies with smaller wing widths to fly well.

Accepted Answer

# Brief Explanations:
1. Analyze the graphs: The "Sample at start" has a peak at 0.9 mm and some smaller/larger widths. The "Sample at end" has peaks at 1, 1.1, 1.2 mm, with no small widths (0.7, 0.8, 0.9). So average wing width **increased**.
2. Natural selection: Flies with traits (larger wings) better suited to the new environment survive/reproduce more. Since larger wings help in cold, if smaller wings were less fit, it implies the environment got **colder** (so smaller wings, good for hot, are now at a disadvantage—weather is too "cold" for them to fly well? Wait, no: Wait, the first info: smaller wings fly better hot, larger cold. So if at the end, larger wings are more common, that means the environment became cold. So:
   - Average wing width: increased (because the sample at end has more large widths, less small).
   - Flies with smaller wings: less likely to survive/reproduce (since their trait is less fit now).
   - Temperature change: increased (got colder? Wait, no—wait, "smaller wings fly better hot, larger cold". So if the population shifts to larger wings, the environment must have become cold (so larger wings are favored). So average temperature in environment **decreased** (got colder). Then, the weather is more frequently too "cold" for smaller wings? No—wait, smaller wings are good for hot. So if the environment is now cold, the weather is too "cold" for smaller wings to fly well (since they fly better in hot). Wait, maybe I mixed up. Let's re-express:
   - Initial info: Smaller wings → better hot; Larger wings → better cold.
   - Graphs: Start sample has 0.7, 0.8, 0.9 (smaller) and 1, 1.1 (larger). End sample has 1, 1.1, 1.2 (larger), no 0.7, 0.8, 0.9. So the population shifted to larger wings.
   - So:
     - Average wing width: increased (because more large wings, fewer small).
     - Flies with smaller wings: less likely (since they are less in the end sample, so they survived/reproduced less).
     - Temperature in environment: increased? No—wait, if larger wings are better in cold, and now larger wings are more, that means the environment is cold. Wait, no—maybe the environment got hot? No, because smaller wings are better in hot. Wait, the end sample has no small wings. So if the environment got hot, smaller wings would be favored, but the end sample has larger wings. So that's a contradiction. Wait, maybe I misread the graphs. Let's check the x - axis: Start sample: 0.7, 0.8, 0.9 (small), 1, 1.1 (large). End sample: 1, 1.1, 1.2 (large), no 0.7, 0.8, 0.9. So the population went from having small and large to mostly large. So the trait of larger wings is favored. Since larger wings are better in cold, that means the environment became cold (so larger wings are favored). So:
       - Average wing width: increased (since the sample at end has higher wing widths on average).
       - Flies with smaller wings: less likely to survive/reproduce (because their trait is not favored in the new environment).
       - Average temperature in environment: decreased (got colder).
       - Weather is more frequently too "cold" for smaller wings? No—smaller wings are good for hot. So if the environment is cold, the weather is too "cold" for smaller wings to fly well (because they need hot to fly well). Wait, but the last blank: "frequently be too ____ for flies with smaller wing widths to fly well". Since smaller wings fly well in hot, if the environment is now cold, the weather is too "cold" for them. But that would mean the environment is cold, so larger wings (good in cold) are favored. So:
         - Average wing width: increased.
         - Smaller wings: less likely.
         - Temperature: decreased (got colder).
         - Weather: too "cold" for smaller wings.
       But let's check the blanks:
       1. The average wing width ____ in the population. → increased.
       2. This suggests that flies with smaller wing widths were ____ likely to survive and reproduce than flies with larger wing widths. → less.
       3. This may have occurred because the average temperature in the flies’ environment ____. → decreased (or "dropped", "got colder").
       4. After the environment changed, the weather would more frequently be too ____ for flies with smaller wing widths to fly well. → cold (because smaller wings fly well in hot; if it's cold, they can't fly well).

Wait, but maybe the temperature increased? No, because that would favor smaller wings. The graphs show the opposite. So the correct sequence is:
       - Average wing width: increased.
       - Smaller wings: less likely.
       - Temperature: decreased (or "dropped").
       - Weather: too "cold".

But let's confirm with the natural selection theory: Organisms with traits better suited to the environment survive and reproduce more. So if larger wings are now more common, that trait (larger wings) is more fit, meaning the environment is now cold (since larger wings are better in cold). So:
       - Average wing width: increased (since the population has more large - winged flies).
       - Flies with smaller wings: less likely (because their trait is not suited to the new cold environment, so they survive/reproduce less).
       - Average temperature: decreased (the environment got colder).
       - Weather: too "cold" for smaller - winged flies (since they are adapted to hot, cold weather is unfavorable for their flight).

# Answer:
1. The average wing width $\boldsymbol{\text{increased}}$ in the population.
2. This suggests that flies with smaller wing widths were $\boldsymbol{\text{less}}$ likely to survive and reproduce than flies with larger wing widths.
3. This may have occurred because the average temperature in the flies’ environment $\boldsymbol{\text{decreased}}$.
4. After the environment changed, the weather would more frequently be too $\boldsymbol{\text{cold}}$ for flies with smaller wing widths to fly well.

Sovi.AI - AI Math Tutor

QUESTION IMAGE

Question

Explanation:

Answer: