Artificial life

People study how living things work. They use computers to make life.

Some people use computer programs. These programs act like tiny living things. They can even make copies of themselves.

Other people use robots. These are machines that can do tasks alone. Some scientists even use tiny living parts.

They study how life might be different. This helps us learn about our world. It is very cool!

Scientists study how life works. They use a field called artificial life. This field is also known as ALife. Researchers look at life in new ways. They use computer models, robots, and chemistry.

There are three main kinds of artificial life. The first kind is soft. This uses software, which is a set of computer rules. These programs can act like living things. They can even make copies of themselves.

The second kind is hard. This uses hardware, or physical machines. These are often robots. Robots are machines that can do tasks on their own.

The third kind is wet. This uses biochemistry, which is the study of chemical changes in life. Scientists try to make tiny cells from scratch. Some even made biological robots. These robots can collect small cells to make copies of themselves.

ALife helps us learn about the world. It helps us see how life could be different.

Artificial life is a very exciting field of study. Scientists call it ALife for short. They want to understand how living things work. They do this by looking at life in new ways. Instead of just studying nature, they build things that act like life. They use computer models, robots, and chemistry to do this.

This work helps us see how life could be different from what we see today.

There are three main ways researchers approach this work. The first way is called soft artificial life. This uses software, which are the programs inside a computer. These programs can follow rules to grow or change. The second way is called hard artificial life. This uses hardware, like physical robots that move on their own.

The third way is called wet artificial life. This uses biochemistry, which is the study of how chemicals work in living things.

This field has a very interesting history. A computer scientist named Christopher Langton gave the field its name in 1986. In 1987, he organized the first big meeting for ALife in Los Alamos, New Mexico.

Later, a researcher named Tom Ray made a program called Tierra. He believed he was not just simulating life, but actually making it. Other scientists, like Sam Kriegman and Douglas Blackiston, have made big discoveries with biological robots recently.

Scientists use many different tools to study these systems. Some use cellular automata, which are simple rules that create complex patterns. Others use neural networks, which are computer systems that can learn like a brain.

In 2019, researchers even changed the DNA of a bacteria called Escherichia coli. They changed its code from 64 parts to 59 parts. In 2021, a team made biological robots that can copy themselves. These robots collect loose cells to build new copies of themselves.

ALife is a lot like the science you might see in a video game. In a game, computer code tells characters how to move and react. In ALife, the code is much more complex and can change on its own. This is called open-ended evolution, where things keep creating new and new behaviors.

It is like watching a digital world grow and change forever. Researchers are still trying to learn how life can start from things that are not alive.

Artificial life, often called ALife, is a scientific field focused on studying systems related to natural life. Researchers examine the processes and evolution of living things using computer simulations, robotics, and biochemistry. Unlike traditional biology, which focuses on "life as we know it," ALife explores "life as it could be." This approach seeks to find the simplest, most general principles that underlie life. By implementing these principles in artificial environments, scientists can analyze new and different lifelike systems.

There are three primary approaches to artificial life, categorized by the medium used. The first is "soft" artificial life, which relies on software and computer models. The second is "hard" artificial life, which uses hardware like robots that can perform tasks autonomously. The third is "wet" artificial life, which uses biochemistry to study life-like processes.

This third category is often called "wetware" because it involves the chemical building blocks of life.

Soft artificial life uses several different technical methods to simulate life. One common method is using cellular automata, which are systems that follow simple rules to create complex patterns. Researchers also use artificial neural networks to model how an agent might have a brain. These networks help simulate population dynamics in organisms that can learn. Another method is program-based simulation, where organisms possess a "genome" made of computer code. In these systems, an organism "lives" when its code is executed, and mutations occur through random changes in that code.

Researchers also use module-based and parameter-based techniques in software simulations. In module-based systems, individual parts are added to a creature to change its behavior. For example, a specific leg type might increase an organism's speed or its metabolism. Parameter-based simulations work differently by using fixed behaviors controlled by mutating numbers. Each number, or parameter, controls a specific aspect of the organism in a defined way. These methods allow scientists to observe how complex behaviors emerge from simple starting rules.

The history of ALife is tied to key figures and milestones. The discipline was named by American computer scientist Christopher Langton in 1986. In 1987, Langton organized the first official conference on the subject in Los Alamos, New Mexico. Later, researcher Tom Ray developed a program called Tierra. Ray famously claimed that Tierra was not merely simulating life, but was actually synthesizing it. These early works helped define the debate between "strong" and "weak" ALife positions.

The "strong" ALife position suggests that life is a process that can exist independently of any specific physical medium. This idea is rooted in the work of John von Neumann regarding cellular automata and universal constructors. He demonstrated that self-reproduction could be achieved by logic-based machines regardless of their physical substrate. In contrast, the "weak" ALife position argues that a true living process cannot exist outside of a chemical solution. Instead, weak ALife researchers use simulations only to understand the mechanics of biological phenomena.

Recent breakthroughs in "wet" artificial life have pushed the boundaries of what is possible. In May 2019, researchers created a new synthetic form of viable life using a variant of the bacteria Escherichia coli. They achieved this by reducing the natural number of codons in the bacterial genome from 64 to 59. In 2020, Sam Kriegman and Douglas Blackiston created a biological robot aided by artificial intelligence. By 2021, they developed Xenobots, which were the first biological robots capable of kinematic self-replication. These organisms do not use traditional birth; instead, they collect loose cells to assemble new copies of themselves.

One of the biggest goals in this field is achieving Open-Ended Evolution (OEE). OEE is the ability of a system to continually produce new, complex, and adaptive behaviors. A system with OEE does not reach a stable end-point or a predefined finish line. While natural life shows this quality, current artificial systems have not yet fully replicated it. Scientists continue to ask how life can arise from nonliving matter and how intelligence might emerge in artificial living systems.