Abstract
Biological data generally contain complex and high-dimensional samples. In addition, the number of samples in biological datasets is much fewer than the number of features, so the vast number of features should be selected carefully and determine the optimal subset of features. Feature selection (FS) is a vital stage in biological data mining applications (e.g., classification) for dealing with the curse of dimensionality problems and finding highly informative features. This work proposes an effective FS approach based on a new version of Gray Wolf Optimizer (GWO) called Multi-strategy Gray Wolf Optimizer (MSGWO) for better features selection for biological data classification. The use of MSGWO in feature selection is to find the optimal subset of features between classes, solve premature convergence, and enhance the local search ability of the GWO algorithm. Multiple exploration and exploitation strategies are proposed to enhance the global search and local search abilities of the GWO algorithm through the optimization process. The support vector machine (SVM) classifier is used to evaluate the proposed GWO-based FS approaches. MSGWO was evaluated on thirteen high-dimensional biological datasets obtained from the UCI repository with a smaller number of instances. The reported results confirm that employing multiple exploration and multiple exploitation strategies is highly useful for enhancing the search tendency of the MSGWO in the FS domain. Statistical tests proved that the superiority of the proposed approach is statistically significant as compared to the basic GWO and similar wrapper-based FS techniques, including binary particle swarm optimization (BPSO), binary bat algorithm (BBA), binary gravitational search algorithm (BGSA), and binary whale optimization algorithm (BWOA). In terms of classification accuracy, MSGWO yielded better accuracy rates than the standard GWO algorithm on 84% of applied biological datasets. MSGWO also recorded better accuracy rates than its other competitors in all 13 cases. In terms of the lowest number of selected features, MSGWO yielded excellent reduction rates compared to its peers.