Question

.Suppose a farmer is interested in developing a breeding program on his chicken farm. The farmer would like to artificially select for egg weight, egg shape, shell color, and shell thickness. In a large population of his chickens, the farmer has measured these four continuous egg traits of interest and calculated their variances, which are shown in the table.

Variance

Weight

Shape

Shell Color

Shell thickness

Phenotypic

503

246

37

526

Additive Genetic

12

33

19

15

Environmental

250

96

17.5

220

Dominance genetic

16

120

4

23

Which trait would best respond to artificial selection by the farmer?

egg weight

egg shape

shell color

shell thickness

Select all of the statements that identify how the farmer might utilize the information gained from his data.

A) Identify quantitative trait loci correlated to each trait examined in the chicken population after obtaining genetic sequence data for his chicken population.

B) Recommend a selective breeding program for a population of chickens from another country based on his results.

C) Further inbreed the chickens on the farm with the largest egg weight to improve the overall phenotype.

D) Design an experiment to improve the weight trait in the current chicken population by changing the farm environment.

Answer 1

The trait of shell color will best respond to artificial selection due to its highest heritability. The farmer can use the data to identify quantitative trait loci and to design experiments around environmental factors influencing egg weight.

Step-by-step explanation:

To determine which trait would best respond to artificial selection by the farmer, we need to consider the heritability of the traits. Heritability in a broad sense is the proportion of the total phenotypic variance that is attributable to genetic variance. Therefore, we can calculate the heritability for each trait using the formula:
Heritability (h^2) = Additive Genetic Variance / Total Phenotypic Variance.

For the traits provided by the farmer, we would have the following calculations of heritability:

Egg weight: h^2 = 12 / 503

Egg shape: h^2 = 33 / 246

Shell color: h^2 = 19 / 37

Shell thickness: h^2 = 15 / 526

The trait with the highest heritability will respond the best to artificial selection. After doing the calculations, shell color appears to have the highest heritability and would thus be expected to respond the best to artificial selection.

As for how the farmer might utilize the information gathered, the following statements are relevant:

Identify quantitative trait loci correlated to each trait examined in the chicken population after obtaining genetic sequence data for his chicken population.

Design an experiment to improve the weight trait in the current chicken population by changing the farm environment.

Options B and C are not directly supported by the information presented. Recommending a selective breeding program for chickens from another country would require additional knowledge about the genetics and environment of that country's chicken populations. Additionally, further inbreeding the chickens on the farm to improve a single phenotype like egg weight can be risky without considering the genetic diversity required to maintain a healthy population.

Answer 2

Egg weight would best respond to artificial selection by the farmer. The farmer can utilize the information gained from the data to identify genetic factors associated with the traits and implement selective breeding practices.

Step-by-step explanation:

Egg weight would best respond to artificial selection by the farmer, as it has the lowest environmental variance among the traits measured. This indicates that the variation in egg weight is mainly due to genetic factors, making it more likely to be influenced by selective breeding.
The farmer can utilize the information gained from the data in the following ways:
A) By identifying quantitative trait loci (QTL) correlated to each trait, the farmer can determine specific genes responsible for the traits of interest.
C) Inbreeding the chickens with the largest egg weight can improve the overall phenotype, as egg weight has a high additive genetic variance.
D) Designing an experiment to improve egg weight by changing the farm environment may not be necessary, as egg weight has a low environmental variance.