An experiment is performed with peppered moths. The table below shows the populations of light-colored moths and dark-colored moths before and after the trees turned black.

\begin{tabular}{|c|c|c|c|c|}
\cline { 2 - 5 } \multicolumn{1}{c|}{} & \multicolumn{2}{|c|}{Starting population} & \multicolumn{2}{c|}{Ending population} \\
\hline Environment & \begin{tabular}{c}
Light-colored \\
moths
\end{tabular} & \begin{tabular}{c}
Dark-colored \\
moths
\end{tabular} & \begin{tabular}{c}
Light-colored \\
moths
\end{tabular} & \begin{tabular}{c}
Dark-colored \\
moths
\end{tabular} \\
\hline \begin{tabular}{c}
Light-colored \\
trees
\end{tabular} & 20 & 20 & 25 & 15 \\
\hline \begin{tabular}{c}
Dark-colored \\
trees
\end{tabular} & 20 & 20 & 5 & 35 \\
\hline
\end{tabular}

Which best describes the results of this experiment?

A. The dark-colored moths were more fit.
B. The light-colored moths could not survive.
C. The dark-colored moths lost their adaptation.



Answer :

To determine which option best describes the results of the experiment, let's analyze the given data step by step.

1. Starting Populations:
- On light-colored trees:
- Light-colored moths: 20
- Dark-colored moths: 20
- On dark-colored trees:
- Light-colored moths: 20
- Dark-colored moths: 20

2. Ending Populations:
- On light-colored trees:
- Light-colored moths: 25
- Dark-colored moths: 15
- On dark-colored trees:
- Light-colored moths: 5
- Dark-colored moths: 35

3. Changes in Population:
- For light-colored trees:
- Change in light-colored moths: [tex]\( 25 - 20 = 5 \)[/tex]
- Change in dark-colored moths: [tex]\( 15 - 20 = -5 \)[/tex]
- For dark-colored trees:
- Change in light-colored moths: [tex]\( 5 - 20 = -15 \)[/tex]
- Change in dark-colored moths: [tex]\( 35 - 20 = 15 \)[/tex]

4. Evaluate the fitness based on population changes:
- On light-colored trees:
- Light-colored moths: Increased by 5
- Dark-colored moths: Decreased by 5
- On dark-colored trees:
- Light-colored moths: Decreased by 15
- Dark-colored moths: Increased by 15

From these observations, we can infer the relative fitness of the moths in each environment:
- On light-colored trees, the light-colored moths were more fit since their population increased, while the dark-colored moths' population decreased.
- On dark-colored trees, the dark-colored moths were more fit since their population increased, while the light-colored moths' population decreased.

Conclusion:
The best description of the results of this experiment is:
- A. The dark-colored moths were more fit.

This choice highlights the increased fitness and survival of dark-colored moths in the transformed environment (dark-colored trees), which led to an increase in their population.