n a Star Trek episode, a population of tribbles (average weight of 56 grams) invade a Klingon starship. The Klingons enjoy eating the tribbles they can find. A Romulan spy smuggles the remaining tribbles (average weight of 21 grams) to Romulus prime. The offspring of the smuggled tribbles have an average weight of 23 grams.

What is the selection differential (S) for this event?

To calculate the selection differential (S), we need to determine the difference between the average weight of the original population and the average weight of the selected individuals (tribbles that were eaten or smuggled).

In this case, we have three populations with different average weights:
1. Original population average weight: 56 grams
2. Tribbles that were eaten average weight: Unknown
3. Tribbles that were smuggled average weight: 21 grams
4. Offspring of the smuggled tribbles average weight: 23 grams

To find the selection differential, we need to know the average weight of the tribbles that were eaten. Unfortunately, this information is not provided in the question. Without this data, it is not possible to calculate the selection differential accurately.

The selection differential measures the difference in average phenotype between the selected individuals and the original population. In this case, the selected individuals are the tribbles that were eaten and the tribbles that were smuggled. However, since we don't have the average weight of the eaten tribbles, we cannot calculate the selection differential.