When a trait is highly heritable,                   . a. it is influenced by genes; b. it is not influenced by the environment; c. the variance of the trait in a population can be explained primarily by variance in genotypes; d. A and C are correct; e. A, B, and C are correct

Verified step by step guidance

1. Understand the term 'heritable': Heritability in genetics refers to the proportion of observed variation in a particular trait that can be attributed to inherited genetic factors in contrast to environmental ones.
2. Analyze option a: Recognize that if a trait is highly heritable, it suggests a strong genetic influence on that trait.
3. Analyze option b: Consider whether the absence of environmental influence is implied by high heritability. High heritability does not mean the environment has no influence, but rather that the genetic factors play a larger role in the variation observed.
4. Analyze option c: Understand that if a trait's variance in a population is primarily explained by variance in genotypes, it indicates a high heritability.
5. Evaluate options d and e: Based on the analysis of options a, b, and c, determine which combination of these statements is accurate when a trait is highly heritable.

Key Concepts

Heritability

Heritability is a measure of how much of the variation in a trait within a population can be attributed to genetic differences among individuals. It is expressed as a value between 0 and 1, where a higher value indicates a greater genetic influence. Importantly, heritability does not indicate the extent to which a trait is determined by genes in an individual, but rather how much genetic factors contribute to differences in the trait across a population.

Environmental Influence

Environmental influence refers to the impact that external factors, such as nutrition, climate, and social interactions, have on the expression of traits. While heritable traits are influenced by genetics, environmental factors can also play a significant role in shaping phenotypes. Understanding the balance between genetic and environmental contributions is crucial for interpreting heritability estimates.

Genotype-Phenotype Relationship

The genotype-phenotype relationship describes how the genetic makeup (genotype) of an organism interacts with environmental factors to produce observable traits (phenotype). In cases of high heritability, the variation in phenotypes within a population is largely explained by differences in genotypes, suggesting that genetic factors are the primary drivers of trait expression. This concept is essential for understanding the implications of heritability in evolutionary biology and genetics.