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We Still Don’t Really Know What Life Is

The most fundamental question in biology still goes unanswered, and we might not have that answer for a long time

By Olivia L. DobbsPublished 2 months ago 5 min read
We Still Don’t Really Know What Life Is
Photo by NASA on Unsplash

Biology is the study of life. Over its evolution, its laws and theories have helped us develop a myriad of fascinating understandings and technologies. But, despite multiple hundreds of years of development and advancement, it isn’t yet complete. In fact, our journey into the study of life has only just begun.

Biologists, despite all they’ve learned about earth and humanity, still don’t truly know the answer to the most fundamental question: “What is life?”

You see, all we currently have access to is one example of life: Earth and its inhabitants. We don’t rightly know how representative our little blue planet is of possible living experiences. It could very well be the perfect example species but, until we find other instances of life elsewhere in the universe, we won’t know. Until data presents itself, it’s all speculation.


Considering the origin of life and evolution, every living being on our planet is the result of one instance of life happening. In the beginning, life originated from a singular source. Through billions of years of genetic diversity, selection, and evolution, life on Earth has resulted in every plant, animal, and microbe we know of. Because of this, we only truly count as a single data point.

Based on the one instance of life we know, our current definition is as follows:

Life is a characteristic of a living organism that distinguishes the latter from a dead organism or a non-living thing, as specifically distinguished by the capacity to grow, metabolize, respond (to stimuli), adapt, and reproduce. Life may also pertain to the biota of a particular region. (From

Though the definition seems wholly adequate from our frame of reference, we still don’t know what we don’t know. If we had other examples, say, some on other planets, we could begin to form a better idea of what is common to all life in the universe. Any of the criteria above has the chance to be unique to Earth’s life. Metabolism could be our planet’s uniqueness, reproduction could be bizarre and Earthian.

A proper scientific study seldom focuses on a single data point. And yet, scientists are in a particularly strange scenario in our lonely solar system. In scientific research, drawing conclusions from a single data point is generally considered unreliable. Scientists aim for statistical significance, which requires a sufficient sample size and data from multiple independent sources. By collecting data from diverse sources and conducting repeated experiments, researchers can identify patterns, trends, and correlations, and reduce the influence of outliers or random fluctuations.

And yet, biologists are stuck with that aforementioned lonely data point: Earth. We need more examples of life to even begin to understand the universe. Studying a broader range of life forms and seeking examples of life beyond Earth is essential for advancing our understanding of life's fundamental nature and its potential distribution in the universe. And it's imperative that this pursuit is a multidisciplinary endeavor too.

Astronomy and planetary science are constrained by the physical distance between celestial bodies. So far, humans have only been able to explore a few of the bodies in our solar system directly, such as the Moon, Mars, Venus, and some of the moons of the gas giants. This limited accessibility restricts the number of data points scientists can study compared to other scientific disciplines.

As technology advances and space exploration capabilities improve, scientists are actively seeking opportunities to study more exoplanets and distant celestial bodies to broaden our understanding of the universe and the potential for life beyond our solar system. The search for exoplanets and the study of extremophiles (organisms that thrive in extreme environments) on Earth are among the ways scientists are expanding their understanding of life's possibilities beyond the confines of our lonely solar system.

Despite the ability of brilliant scientists to approximate what extraterrestrial life might be like, the search for life on other planets is our best bet at finding the answer. The emerging field around this scientific pursuit, astrobiology, is a multidisciplinary scientific discipline that seeks to understand the origin, evolution, and distribution of life in the universe, including the possibility of life beyond Earth.

We’re still a long way away, however, from being able to find more life. The closest planets we’ve found that have the potential to harbor living beings are lightyears away.

But note that the field of exoplanet research is rapidly evolving and, if you’re reading this article long after its publication, discoveries may have been made since the last edit. To see recent developments in this field, see ESA or NASA.

The vast distances between habitable exoplanets and our solar system present significant challenges for interstellar travel. The current state of space exploration technology and propulsion systems is not sufficient to undertake such long journeys within practical timescales. To make interstellar travel possible and reduce the travel time spanning generations, we'll need to develop much more advanced rocket ships and propulsion technologies.

So, what exactly can we say with certainty right now? Unfortunately, not much. But, for those that enjoy pioneering postulations, the emerging field of astrobiology awaits you.

For now, our definition remains a guess. Only advancement and discovery will be able to reveal to us whether it’s founded in reality.

Are we alone in the universe? Could life exist beyond our planet? By studying the origins, evolution, and potential distribution of life in the cosmos, astrobiology unravels the enigmatic tapestry of existence itself. Embrace the thrill of investigating extreme environments on Earth, where life defies all odds, and then venture beyond, gazing at distant exoplanets that may harbor secrets of life's diversity. Astrobiology beckons you to unlock the mysteries of our place in the universe and to inspire your imagination with the limitless possibilities of life beyond our home planet. Join the quest to expand our cosmic horizons and embrace the endless wonder that awaits in the captivating realm of astrobiology.


About the Creator

Olivia L. Dobbs

Science Enthusiast, Naturalist, Dreamer.

Check out my science! ->

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