‘Sara Imari Walker, a theoretical physicist and astrobiologist at Arizona State University, has a radical new theory that purports to transform our understanding of what it is to be alive.

Most attempts to describe life use Earth as a blueprint. Instead, by pushing past cells and their chemistry to general principles about how complex objects come into existence, Walker claims to have reached a deeper understanding.

The idea, known as Assembly Theory, explains why certain complex objects have become more abundant than others by placing fresh emphasis on their histories. Now, Walker and her colleagues are testing the theory on lab-grown microworlds. In experiments, they have already discovered a threshold – namely the number of steps on the way to complexity – that seems like it must be met for something to be considered alive.

If Assembly Theory proves correct, she tells New Scientist, it will redefine what we mean by “living” things and show that we have been going about the search for life beyond Earth all wrong. In the process, she says, we could even end up creating alien life in a laboratory….’ (New Scientist)