What percentage of sheep had a body height of 1.2 meters or more 30 years ago? How does it differ from the present data? Does this data support your argument regarding the type of selection occurring?
Answer (1)
Without the actual data, a numerical answer cannot be provided. The approach involves calculating the difference between past and present percentages of sheep with a body height of 1.2 meters or more. The sign and magnitude of this difference can suggest the type of selection occurring (directional, stabilizing, or disruptive). Data is needed to provide a concrete answer.
Explanation
Problem Analysis The problem requires us to determine the percentage of sheep with a body height of 1.2 meters or more 30 years ago, compare it to the present data, and assess whether the data supports an argument about the type of selection occurring. Unfortunately, the actual data regarding sheep body heights 30 years ago and present day is missing. Without this data, a numerical answer cannot be provided. However, I can outline a general approach assuming we had the data.
Calculating the Difference Assuming we have the percentage of sheep with a body height of 1.2 meters or more 30 years ago ( P 30 ) and the present percentage ( P p rese n t ), we would calculate the difference D = P p rese n t − P 30 . If 0"> D > 0 , it means the percentage has increased. If D < 0 , it means the percentage has decreased. If D = 0 , there is no change.
Inferring the Type of Selection Based on the sign and magnitude of D , we can infer the type of selection. For example:
Directional Selection: If 0"> D > 0 and significantly large, it suggests directional selection favoring taller sheep.
Stabilizing Selection: If D is close to 0, it suggests stabilizing selection, where the average height is favored.
Disruptive Selection: This is harder to infer without more detailed data, but if we see a bimodal distribution (which we don't have), it might suggest disruptive selection.
Hypothetical Example and Conclusion Without the actual data, I cannot provide a specific percentage or definitively say what type of selection is occurring. A hypothetical example: If 30 years ago, 10% of sheep were 1.2 meters or taller, and now 20% are, then D = 20 − 10 = 10% . This increase might suggest directional selection favoring taller sheep.
Examples
In livestock breeding, understanding how traits like body height change over time can help farmers make informed decisions about which animals to breed. If they want taller sheep, they might select for taller individuals. If they want to maintain a certain height, they might select against extremes. This analysis helps understand the effectiveness of these strategies.
