Question

A strawberry farmer determines that the average weight of individual strawberries produced by plants in his garden is 2g. He selects 10 plants that produce the largest strawberries; the average weight among the selected plants is 6g. He interbreeds these selected strawberry plants. The progeny of these strawberry plants produce strawberries that weigh 5g. What is the realized heredity for this trait? *Please help, already know how to use h² and H², not sure how to answer realized heredity.

Answer 1

ANSWER:

Population biologists often used an index called Realized heritability, h², to quantify the degree to which a trait in a population can be pushed by selection.

To calculate this index, find the response to selection by subtracting the average of the second generation from that of the entire first generation,

Then find the selection differential by subtracting the average of the selected parents from that of the entire generation.

Realized heritability is the response divided by the differential

Realized heritability = response to selection

selection differential

Realized heritability = average of the first-generation _- average selected parents

average second generation - average selected parents

=   5gm-2g

6gm-2g   

=3gm

4gm

h² =0.75gm

A low h² (less than 0.1) occurs when the offspring of the selected parents differ little from the original population, in spite of a big difference between the population as a whole and the selected parents.

A high h² (greater than 0.6) occurs when the offspring of the selected parents differ from the original population almost as much as the selected parents do.

In this case realized heritability h2 for this trait is high, 0.75gm