The problem of how life evolved on Earth has intrigued the minds of many great scientists for centuries. Now, according to an exciting study published in the Proceedings of the National Academy of Sciences (PNAS), scientists from Harvard University may be a step closer to figuring out how life on Earth was formed. Using their skills and knowledge, scientists from the prestigious university have managed to build cells which are not alive in any way, yet can self-reproduce, grow and evolve without making use of any biological component of a live entity. Their findings are expected to generate heated discussions about abiogenesis, synthetic life forms, artificial cells, evolution theory, origin of life studies, and self-reproducing systems.
How Harvard scientists created self-reproducing cells using only non-living chemicals
Self-reproduction as an autonomous process of growth and reorganisation in fully abiotic, artificial and synthetic cells was conducted by Sai Krishna Katla, Chenyu Lin and Juan Pérez-Mercader at Harvard University and the Santa Fe Institute.Scientists started their research by using a fully homogeneous solution of non-living substances. After irradiating the substance with green light, it formed vesicle-like structures similar to those in primitive cells. The artificial protocells underwent development, reorganisation and reproduction autonomously.As stated in the paper titled ‘Self-reproduction as an autonomous process of growth and reorganisation’ in fully abiotic, artificial and synthetic cells, self-reproduction was “one of the main features of a biological organism”. In other words, the experiment showed that the structure had a feature of life.In contrast to many other artificial biology experiments, the reproduction did not require living cells, DNA, RNA, proteins and membrane-like structures. It was done purely by chemical means.
How Darwinian evolution may begin before life exists
One of the most fascinating aspects of this experiment is its relation to Darwinian evolution and the origins of life.The artificial cells created new generations of vesicles and populations that could grow and diversify. Though they are not alive, researchers say that these systems might be an intermediary step between the two states, the point where chemistry transitions to biology.“The ability to evolve in this fashion from completely non-living, homogeneous materials to structures that can grow and diversify is completely unprecedented,” said Juan Pérez-Mercader of Harvard University, the paper’s senior author.“This is the first time, as far as I know, that anybody has done anything like this, generate a structure that has the properties of life from something which is completely homogeneous at the chemical level and devoid of any similarity to natural life.”Moreover, the results imply that life does not necessarily need all the sophisticated machinery present in biological cells to start developing.Indeed, this theory seems consistent with past scientific findings according to which selection and evolution occurred before the emergence of actual living entities. A 2021 study from Ludwig Maximilian University of Munich showed that simple organic polymers can undergo a selection process in prebiotic conditions.
A breakthrough in the origins of life research
The findings have attracted attention from researchers working in synthetic biology, astrobiology and evolutionary science.Harvard University’s Origins of Life Initiative described the work as an important advance in understanding how simple chemical systems might transition into living systems. According to Harvard astronomer Dimitar Sasselov, the study demonstrates how a self-creating system can emerge from non-biochemical molecules.Kermit Pattison, who was not involved in the research, commented in a piece in PhysOrg that the work opens a new route towards engineering self-reproducing synthetic systems.The implications extend beyond understanding Earth’s past. Scientists believe similar chemical processes could potentially occur elsewhere in the universe, broadening the search for extraterrestrial life.
What this means for the future of synthetic life
While the synthetic cells are not technically living, the work is a landmark achievement in the fields of artificial life and abiogenesis.Scientists have long sought to determine what chemical processes led to biological processes. Through this new process, it is possible to see how organization, reproduction, and evolution can happen from rather basic elements when certain conditions are present.By no means does this create life; however, it presents a credible route for the transition of chemistry to biology. With continued advancements from this breakthrough, it may become possible to recreate what occurred to bring about life on Earth.
