Then, in a step similar to natural selection, a portion of the candidate antennas with the worst scores are discarded, leaving a smaller population of the highest-scoring designs.
The first evolved antenna designs appeared in the mid-1990s from the work of Michielssen, Altshuler, Linden, Haupt, and Rahmat-Samii.
Most practitioners use the genetic algorithm technique or some variant thereof to evolve antenna designs.
Their external appearance was essentially identical in that a foam radome covered the radiating elements.
Other evolved antennas were subsequently used on the Lunar Atmosphere and Dust Environment Explorer spacecraft.