Neural Networks for self-adjusting Mutation Rate Estimation when the Recombination Rate is unknown
Estimating the mutation rate, or equivalently effective population size, is a common task in population genetics. If recombination is low or high, the optimal linear estimation methods, namely Fu’s and Watterson’s estimator, are known and well understood. For intermediate recombination rates, the calculation of optimal estimators is more involved. As an alternative to model-based estimation, neural networks and other machine learning tools could help to develop good estimators in these involved scenarios. However, if no benchmark is available it is difficult to assess how well suited these tools are for different applications in population genetics.Here we investigate feedforward neural networks for the estimation of the mutation rate and compare their performance with the frequently used optimal estimators introduced by Fu and Watterson. We find that neural networks can reproduce the optimal estimators if provided with the appropriate features and training sets. Remarkably, only one hidden layer is necessary to obtain a single estimator that performs almost as well as the optimal estimators for both, low and high recombination rates and provides a superior estimation method for intermediate recombination rates at the same time.