In domesticated dogs, size has a high heritability, andthe trait is determined by only a small number ofgenes. In contrast, genetic variation at more than180 QTLs explains only a very small proportion ofthe high heritability for height in humans. What couldexplain the missing heritability in humans, and howcould you test your hypothesized explanations?
Genetic Variation
Genetic variation refers to the variation in the genome sequences between individual organisms of a species. Individual differences or population differences can both be referred to as genetic variations. It is primarily caused by mutation, but other factors such as genetic drift and sexual reproduction also play a major role.
Quantitative Genetics
Quantitative genetics is the part of genetics that deals with the continuous trait, where the expression of various genes influences the phenotypes. Thus genes are expressed together to produce a trait with continuous variability. This is unlike the classical traits or qualitative traits, where each trait is controlled by the expression of a single or very few genes to produce a discontinuous variation.
In domesticated dogs, size has a high heritability, and
the trait is determined by only a small number of
genes. In contrast,
180 QTLs explains only a very small proportion of
the high heritability for height in humans. What could
explain the missing heritability in humans, and how
could you test your hypothesized explanations?
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