Heritability of body length in Drosophila nasuta is 0.5. This value comes from applying the breeder’s equation to the given data on population mean, selected parents, and progeny mean. The calculation uses realized heritability from artificial selection.

Key Concept

Narrow-sense heritability (h²) measures the proportion of phenotypic variance due to additive genetic variance, predicting response to selection. The breeder’s equation is R = h²S, where R is the response to selection (progeny mean minus population mean) and S is the selection differential (selected parents’ mean minus population mean).

Step-by-Step Solution

1. Population mean (P̄) = 2 mm.
2. Selected parents’ mean = 3 mm, so S = 3 – 2 = 1 mm.
3. Progeny mean = 2.5 mm, so R = 2.5 – 2 = 0.5 mm.
4. Thus, h² = R/S = 0.5/1 = 0.5.
5. Rounded to one decimal place: 0.5.

Drosophila nasuta body length heritability from Andaman and Nicobar Islands populations is a key CSIR NET and GATE Life Sciences question. This example demonstrates narrow-sense heritability calculation using artificial selection data.

Heritability Basics

Heritability (h²) quantifies additive genetic influence on traits like body length in Drosophila nasuta. In this Andaman and Nicobar population, average body length is 2 mm. Selecting 3 mm individuals mimics directional selection, revealing genetic potential.

Data Analysis

• Population mean: 2 mm
• Selected parents (males/females): 3 mm
• Progeny mean: 2.5 mm

Selection differential S = 1 mm; response R = 0.5 mm. Breeder’s equation gives h² = 0.5, indicating half the phenotypic variation is additively genetic.

Exam Relevance

This matches , testing quantitative genetics for CSIR NET aspirants. Body size heritability in Drosophila ranges 0.26-0.84, aligning with 0.5 here. Practice similar problems on parent-offspring regression.