What’s the best way to understand ancient life on Earth? Replicate the conditions it survived in. 

NASA astrobiologist Betül Kaçar is recreating conditions from 3 billion years ago to study how microbes have evolved throughout history. By studying the way life once endured a frozen, unstable planet, Kaçar and her team are hoping to find clues for how we might face environmental challenges today and prepare for what’s coming next.

BETÜL KAÇAR: Technology alone is not going to fix our problems. And there's a very simple reason for this. Because technology is not going to suffer the consequences of planetary extremes.

Our planet has gone through a lot. It did not have oxygen for the first 2 billion years. It had different oceans. It had different atmosphere. In fact, it was an oceanic planet altogether that froze multiple times over the course of hundreds of millions of years. And every time it was biology that suffered the consequences.

But microbes found a way to survive. Not only did they survive—these organisms evolved and tapped into these solutions, and they kept these solutions. By studying these solutions and by traveling back in time and understanding how life learned and responded to the challenges at first place, we may be able to learn how to mitigate current and future problems that our society is facing.

I want to know your origins. Take any chunk of rock in this universe, and you will be able to study the physics, or the chemistry, or even geology of this chunk of rock. However, there is only one chunk of rock that harbors life, and that's the chunk of rock that we live on. So this is the only place that biology exists.

My work looks into the origins and early evolution of microbes. I like to think that if you don't like microbes, this is not the planet for you. Microbes run this planet. About 3 billion years ago, oxygen was created by a microbe. And then the planet shifts into a completely different state. That shift then reshaped evolution and life as we know it. They are the true ancestors of life.

For billions of years, they've found a way to make use of whatever is available around them. They thrive in seemingly inhospitable places, and they will outlive us. That's for sure. Evolution keeps a record of biology solving problems. So when you study organisms that have been around for a long time—and I am referring to microbes—ultimately you are going to be discovering their survival strategies.

In my lab, we bring back those innovations by being almost like a molecular detective, so to speak. By using synthetic biology, we've been able to create a cohort of synthetic systems in the lab that allows us to recapitulate billions of years of evolution in the course of a week or a month.

There's a lot of drama when we bring this ancient DNA back to now and expect them to communicate with the rest of the cell. So we have to find the best conditions for this communication to happen. And with enough patience and enough determination, you can do it.

We change the environment so it is a little bit like the past. We take oxygen away so it resembles where they were a little bit more. We give them a little bit more carbon dioxide, so it feels a little bit more familiar, and then slowly adjust them to the conditions of our own planet now by experimentally evolving them, and then push them a little further.

Let's assume and predict the variety of different environments and see how these molecules will respond to these different conditions. We find that our ancestral enzymes respond differently than the modern organisms and the modern enzymes that are around us today. They are not simply doing what their offspring is doing.

By understanding how microbes evolved and survived under these environmental changes, we can re-engineer and repurpose enzymes and metabolisms that exist around us today.

My group looks into a particular element that is extremely important for life as we know it, and that is nitrogen and nitrogen fixation. The way that the environment is changing in front of our eyes, we will have to think of better ways in order to mitigate how we engineer crops, how we deliver nitrogen more effectively. And we found really remarkable responses when we tracked the survival pathway of these organisms.

For 3 billion years, life has been taking nitrogen in the atmosphere and turning it into a bioavailable form. We found that in the face of really extreme conditions, these microbes kept going and going and going.

Through our work, we were able to understand the origin and evolutionary story of multiple enzymes that humanity needs so bad for our own sustainability. And not just ourselves, but everything that our life depends on.

Now we are in the process of engineering plants with DNA that belongs to a planet that once was, that was different than now, but may not be that different compared to what we are headed towards. When we bring these ancient solutions to currently existing systems, we find that we are able to re-engineer more resilient forms of living systems.

I view life and what is around us as sort of a set of survivors, so to speak, that did not fail the test of time. Over 99% of all species that ever existed on this planet has gone extinct. So we are working with less than a percent of whatever made it thus far. And using that less than a percent to stitch the story of that entire history. I mean, this is harder than resurrecting an ancient language.

The more we study today, the more our past benefits, and the more we understand our past, the more our future benefits. As we explore different planets and life on different planetary bodies, it will really come down to knowing ancient life, and ancient signatures of life. And everything that we will compare and contrast to comes down to our understanding of what life is capable of here.

We are in the process of building a museum of life, so to speak, so that we can visit and understand what are the tools and what are the past stories that enabled life as we know.