SCIENTISTS PROPOSE NEW FRAMEWORK TO DEFINE LIFE

Researchers have put forward a revised framework for understanding what life is, moving away from traditional biological definitions toward a broader theoretical model. The new approach centres on the concept of "assembly theory," which measures the complexity of molecules by calculating the minimum number of steps required to construct them. Scientists argue this method can identify life-associated molecules even without prior knowledge of the biology involved. The framework applies across different chemical systems, making it potentially useful beyond Earth-based biology.

Assembly theory was developed to address a long-standing problem in origin-of-life research: existing definitions of life are largely built around the biology found on Earth. Traditional criteria such as reproduction, metabolism, and cellular structure may exclude forms of life that operate on different chemical foundations. Proponents of assembly theory contend that high molecular complexity, as measured by their system, reliably signals biological processes regardless of the underlying chemistry. The approach has been tested against both living samples and non-living chemical controls, with researchers reporting it distinguished the two categories accurately.

The framework carries direct implications for the search for extraterrestrial life. Space agencies and research institutions currently design detection instruments based on Earth-centric biological markers, which may miss life forms with different biochemistries. Assembly theory offers a chemistry-neutral detection method that could be incorporated into future mission instruments. Scientists involved in the research have indicated the next step involves further laboratory validation and engagement with instrument designers working on planetary exploration programs.