Using genomic prediction to detect microevolutionary change of a quantitative trait

Detecting microevolutionary responses to natural selection by observing
temporal changes in individual breeding values is challenging. The
collection of suitable datasets can take many years and disentangling the
contributions of the environment and genetics to phenotypic change is not
trivial. Furthermore, pedigree-based methods of obtaining individual
breeding values have known biases. Here, we apply a genomic prediction
approach to estimate breeding values of adult weight in a 35-year dataset
of Soay sheep (Ovis aries). Comparisons are made with a traditional
pedigree-based approach. During the study period adult body weight
decreased, but the underlying genetic component of body weight increased,
at a rate that is unlikely to be attributable to genetic drift. Thus
cryptic microevolution of greater adult body weight has probably occurred.
Genomic and pedigree-based approaches gave largely consistent results.
Thus, using genomic prediction to study microevolution in wild populations
can remove the requirement for pedigree data, potentially opening up new
study systems for similar research.