What is Evolutionary strategies

The Basics of Evolutionary Strategies in AI

Artificial intelligence (AI) is a rapidly expanding field of study that combines computer science, mathematics, and engineering to create intelligent machines. AI has been applied to a wide range of fields, including self-driving cars, healthcare, and finance. One of the key areas in AI that has gained a lot of attention is evolutionary strategies. In this article, we will explore the basics of evolutionary strategies and how they are used in AI.

What are Evolutionary Strategies?

Evolutionary strategies are a subset of evolutionary algorithms that use probabilistic methods to solve optimization problems. These strategies are inspired by the way biological evolution works through the process of natural selection. In essence, evolutionary strategies imitate the process of "survival of the fittest" in order to find the best possible solution to a given problem.

There are two main types of evolutionary strategies: 1) evolution strategies (ES) and 2) covariance matrix adaptation evolution strategies (CMA-ES). Both of these strategies are used to solve optimization problems, but they differ in the way they operate.

  • Evolution Strategies
  • Evolution strategies (ES) are a type of evolutionary algorithm that uses mutation and selection to search for optimal solutions. The algorithm starts with an initial population of candidate solutions, each of which is randomly generated. The algorithm then iteratively mutates the candidate solutions and evaluates them. The mutations can be random or guided by some heuristic, such as gradient descent. The best solutions are selected to form the next generation of candidate solutions, and the process is repeated until a satisfactory solution is found.

  • Covariance Matrix Adaptation Evolution Strategies
  • Covariance matrix adaptation evolution strategies (CMA-ES) are a more advanced type of evolutionary strategy that adaptively change the mutation distribution. In CMA-ES, the algorithm starts with an initial population of candidate solutions, just like ES. The algorithm then uses a covariance matrix to adaptively change the mutation distribution. This allows the algorithm to efficiently explore the search space and find optimal solutions.

Applications of Evolutionary Strategies in AI

Evolutionary strategies can be applied to a wide variety of AI problems. Some of the most common applications of evolutionary strategies include:

  • Optimization Problems
  • Evolutionary strategies are often used to solve complex optimization problems. These problems are typically difficult to solve using traditional optimization methods and require the use of probabilistic methods like evolutionary strategies to find optimal solutions. Examples of optimization problems that can be solved using evolutionary strategies include parameter optimization, feature selection, and model selection.

  • Robotics
  • Evolutionary strategies can be used to optimize the behavior of robots. For example, they can be used to find the optimal gait for a robot or to optimize the weights of the neural network controlling a robot's behavior. This can help robots move more efficiently and carry out tasks more effectively.

  • Game Playing
  • Evolutionary strategies can be used to develop game playing agents that can learn and improve their strategies over time. The agents can be trained to play games like chess, poker, and Go. By using evolutionary strategies, the agents can learn to make better decisions and become more competitive.

Advantages of Evolutionary Strategies in AI

Evolutionary strategies offer several advantages over traditional optimization methods:

  • Efficiency
  • Evolutionary strategies can be highly efficient, especially when used to optimize complex problems. They are able to explore large search spaces quickly and can converge to optimal solutions faster than many other methods.

  • Robustness
  • Evolutionary strategies are highly robust and can handle noisy, unpredictable, and dynamic environments. They are able to adapt to changing conditions and can continue to find optimal solutions even in the face of uncertainty.

  • Flexibility
  • Evolutionary strategies are highly flexible and can be used to solve a wide variety of problems. They can be used in combination with other optimization and machine learning methods to create hybrid approaches that are specifically tailored to the problem at hand.

Challenges and Limitations of Evolutionary Strategies in AI

While evolutionary strategies offer several advantages over traditional optimization methods, there are also some challenges and limitations to consider:

  • Computational Complexity
  • Evolutionary strategies can be computationally expensive, especially when dealing with large search spaces or complex problems. This can make them impractical for some applications that require faster solutions.

  • Difficulty of Tuning Parameters
  • Evolutionary strategies rely on several parameters that need to be tuned in order to achieve optimal performance. These parameters can be difficult to set correctly, and tuning them can be time-consuming and difficult.

  • Need for Diversity in Population
  • Evolutionary strategies require diversity in the initial population to ensure that the algorithm has enough variation to explore the search space effectively. This can be challenging to achieve and can often require significant preprocessing of the data.


Evolutionary strategies are a powerful subset of evolutionary algorithms that can be used to solve a wide variety of optimization problems in AI. They offer several advantages over traditional optimization methods, including efficiency, robustness, and flexibility. However, they also come with some challenges and limitations that need to be considered. By understanding the basics of evolutionary strategies, AI researchers and practitioners can leverage these powerful methods to create intelligent machines that can solve complex problems and improve our world.