What is life?
This is a much bigger question that it seems on the surface. We seem to have a well established intuition of what life is, but when asked to provide a concise and complete definition of the concept, it is hard to say. Through a course, I recently encountered an article written by biologist Daniel E. Koshland Jr. titled “The Seven Pillars of Life,” which aims to explain seven essential and common characteristics of living organisms. This essay intrigued me to think deeper into the meaning of life, as the very first paragraph counter-argued my vague definition of life as beings capable of reproduction and constant metabolism. According to my definition, a male and a female rabbit are both alive. However, when one of them dies, then the other is incapable of reproduction on its own. Hence, the other would also die, creating a paradox. As Koshland mentions, there is no, at least not until now, one simple definition of life. Today, I would like to invite you to think about the complex layers constituting this question, focusing on two main aspects.
Let’s try applying our intuition of life in technological products. Artificial intelligence and the advancements in robotics that it is producing poses a question. In this era of the Fourth Industrial Revolution, AI is constantly being developed to the point that it is capable of most if not all of manual work, artistic and creative activities, and even logical decision making processes. Many human-like robots powered by AI have the ability to gather massive amounts of data to “feel” human emotions as well. As they are products of careful programming, their bodies consist of elaborate and delicate systems in which each part performs a function, just like the human body. In other words, these robots appear to be extremely similar to human beings and have the capacity to do things that humans do. Sure, one may argue that AI cannot replicate itself, but if, in the near future, AI develops the ability to easily copy its programmed system to generate another identical or more developed artificial intelligence, then is it also alive? What precise definition of life that includes something more than metabolism and reproduction can differentiate humans from robots then?
Another aspect to consider is that life may exist in extraterrestrial environments as well. Most of the news discussing potential life on other planets mention substances such as water and oxygen as evidence of life. Yes, it is true that most living beings on Earth require water and oxygen to function, but how do we know that an alien on Mars would need the same thing? The answer is: we don’t. Human knowledge about the vast and constantly expanding outer space is extremely limited. Perhaps, in a faraway star that we are not even aware of, an organism may breathe nitrogen and drink melted gold or in some other planet, another being may not even need to breathe or drink anything, because its body is built that way. If sometime in the future we come across these beings, can we view them as “alive” even though they do not breathe oxygen and drink water? The apparent answer is yes, but then what does that signify regarding the definition of life?
As we see, “what is life” is a multi-layered question prompting us to consider practically everything around us. If we ask these questions one by one, perhaps a window or a rock or anything else that we never thought of as alive might fit some description of life. I have thought of this question for a while, but still have not developed a satisfying definition of life. What do you think?
Source:
Koshland, Daniel. “The Seven Pillars of Life.” Science’s Compass, vol. 295, 22 March 2002