Partially adaptive antennas are very attractive solution to enhance the desired signal and suppress interference, in communication and radar applications, at a minimum cost. A new design technique, based on the genetic algorithm, has been devised, in order to find the minimum number of controlled elements and their locations in a given linear array. The new technique has been used to steer a given number of nulls towards interfering signal directions and simultaneously reduce the number of controlled elements. The technique is demonstrated using 16-element uniform and Chebyshev arrays. The null steering method used in this work is element position perturbations. Results are given for one and four steered nulls. The results demonstrate the capability of the new technique to steer the array nulls while minimizing the number of controlled elements in the array.