Scientists at the University of Hiroshima in Japan believe they may have solved one of the most enduring mysteries of science – namely, how life originated from inanimate matter in the early cycle of Earth’s development, report from New Atlas explains.
In a new report published in newspaper Nature Communications, researchers describe in detail how they created self-replicating protocells in the laboratory. They believe that this adds weight to the hypothesis of chemical evolution, which was first proposed in the 1920s. It says that “life originally originated with the formation of macromolecules from simple small molecules, and these macromolecules formed molecular assemblies that can reproduce,” explains Muneiki Matsuo, the first author of the study in press release.
Hiroshima researchers have specifically studied the origins of molecular assemblies that multiply from small molecules, as they have remained a mystery since the scenario of chemical evolution was first hypothesized. In a press release from Hiroshima University, Matsuo called them “the missing link between chemistry and biology in the origin of life.”
The common origin of mankind has its origins in its molecular origin
For their study, the researchers aimed to recreate these proliferating protocells in the laboratory. First, they created a new small molecule of amino acid derivatives that would assemble itself into primitive cells. This is added to water at room temperature at normal atmospheric pressure for observation over a period of time.
The researchers found that the molecules were arranged in peptides and then spontaneously formed droplets. By adding more amino acids, the researchers observed that these droplets grew in size and then separated, a process comparable to the self-reproduction of biological cells. “By constructing peptide droplets that multiply by feeding on new amino acid derivatives, we experimentally clarified the long-standing mystery of how the ancestors of prebiotics were able to reproduce and survive by selectively concentrating prebiotic chemicals,” Matsuo said. “Our results show that the droplets have evolved into evolving molecular aggregates – one of which became our common ancestor.” Moreover, during the experiment, some of the droplets also concentrated nucleic acids that carry genetic information. These droplets are also more resistant to external stimuli, researchers say, and are more likely to survive.
Although the findings do not definitively tell us how life on early Earth came into being, they give weight to the hypothesis of chemical evolution and offer additional research opportunities. Scientists have also tested the RNA hypothesis, which states that RNA molecules are the first self-replicating molecules and they eventually led to life on Earth. Other research suggests that asteroids may have brought the necessary components for life on Earth – in July, researchers at the US-based Southwest Research Institute said their findings suggested that city-sized asteroids had once hit Earth. much more often than previously thought, giving weight to this particular hypothesis. Hiroshima researchers then aim to continue their research on amino acids to gain more knowledge about how life could begin on Earth.