A method, apparatus, and computer-readable medium provide automatic geosteering by automatically updating a geosteering structure model based upon observed data gathered during a drilling operation. In some embodiments, automatic updates may be used to introduce vertical shifts into a geosteering structure model to match synthetic log data with observed log data. In addition, in some embodiments an evolutionary algorithm may be used to introduce such vertical shifts and thereby provide an optimal match between the synthetic and observed log data.