The origin of life is one of humanity’s greatest mysteries. For centuries, scientists have sought to understand how the complex systems that govern our world emerged from the simple chemistry of the early Earth. A crucial step in this process is the replication of genetic material, which would have been carried by RNA (ribonucleic acid) molecules before DNA and proteins later took over.

Chemists at UCL and the MRC Laboratory of Molecular Biology have made a groundbreaking discovery that brings us closer to understanding how life began. They’ve successfully recreated the conditions under which RNA might have replicated itself on early Earth, a key process in the origin of life.

The researchers used three-letter “triplet” RNA building blocks in water and added acid and heat, which separated the double helix structure that normally prevents RNA strands from replicating. By neutralizing and freezing the solution, they created liquid gaps between the ice crystals where the triplet building blocks could coat the RNA strands and prevent them from zipping back together, allowing replication to occur.

By repeating this cycle of changes in pH and temperature, which could plausibly occur in nature, the researchers were able to replicate RNA over and over again. This process produced RNA strands long enough to have a biological function and play a role in the origin of life.

The study’s lead author, Dr James Attwater, emphasized that replication is fundamental to biology. “In one sense, it is why we are here,” he said. “But there’s no trace in biology of the first replicator.”

The researchers believe that early life was run by RNA molecules, and their findings provide a possible explanation for how this process could have occurred before life began several billion years ago.

While the study focuses solely on the chemistry, the conditions they created could plausibly mimic those in freshwater ponds or lakes, especially in geothermal environments where heat from inside the Earth has reached the surface. However, this replication of RNA could not occur in freezing and thawing saltwater, as the presence of salt interferes with the freezing process and prevents RNA building blocks from reaching the concentration required to replicate RNA strands.

The origin of life is likely to have emerged out of a combination of RNA, peptides, enzymes, and barrier-forming lipids that can protect these ingredients from their environment. The researchers are uncovering clues about how life began, and their findings bring us closer to understanding this fundamental mystery.
In recent years, teams led by Dr John Sutherland and Professor Matthew Powner have demonstrated how chemistry could create many of the key molecules of life’s origin, including nucleotides, amino acids and peptides, simple lipids and precursors to some of the vitamins, from simple molecular building blocks likely abundant on the early Earth.

The latest study was supported by the Medical Research Council (MRC), part of UK Research and Innovation (UKRI), as well as the Royal Society and the Volkswagen Foundation.

The discovery of a root development gene older than root development itself is a fascinating find in the realm of plant biology. A recent study by Kobe University researchers has shed light on this phenomenon, providing insights into the fundamental evolutionary dynamic of co-opting and adapting mechanisms for new purposes.

The gene in question, called RLF, was previously found to be essential for lateral root development in Arabidopsis thaliana, a model plant commonly used in scientific research. However, it was surprising to discover that the equivalent gene in other plants, specifically liverworts (Marchantia polymorpha), is also involved in organ development.

Liverworts are ancient land plants that lack proper roots, but they do have their own version of the RLF gene. The Kobe University researchers studied this gene’s function and compared it to its Arabidopsis counterpart. They found that liverworts lacking RLF exhibit severe deformations in various organs, demonstrating the gene’s crucial role in organ development.

Furthermore, the study showed that the Arabidopsis gene can perform its function in liverwort cells, and vice versa. This functional interchangeability between the two genes highlights their shared evolutionary history and significance in plant development.

The RLF gene produces a protein that belongs to the heme-binding proteins group, which may bind a molecule called “heme” involved in energy transfer within the cell. The discovery of this mechanism is significant, as it was previously unknown to be involved in organ development in plants.

This research has implications for our understanding of plant evolution and development. By studying how the RLF protein interacts with others, scientists can gain more insights into the evolution of plant organ development. As Kobe University researcher Hidehiro Fukaki notes, “The fact that RLF plays an important role in organ development since at least the dawn of land plants is an example of how evolution often co-opts existing mechanisms for new functions.”

This research was funded by various Japanese institutions and conducted in collaboration with researchers from several universities. The findings have been published in the journal New Phytologist, providing a valuable contribution to our understanding of plant biology and evolution.

A groundbreaking study has shed new light on how animals like the woolly mammoth, musk ox, and arctic fox evolved to thrive in the harsh conditions of the ice age. A team of researchers, consisting of palaeontologists and palaegeneticists, delved into ancient fossil and DNA evidence to unravel the mysteries of adaptation and survival during this pivotal period.

Their findings revealed that cold-adapted animals began to evolve around 2.6 million years ago, as permanent ice at the poles became more prevalent. This was followed by a series of expansions and contractions of continental ice sheets, which led to an increase in the duration of cold periods. It was during this time, approximately 700,000 years ago, that many current cold-adapted species, including extinct ones like mammoths, emerged.

The study’s publication in the journal Trends in Ecology and Evolution has significant implications for understanding how species adapt to climate change. Professor John Stewart, who led the research, emphasized the importance of studying past evolution to better comprehend the risks faced by endangered species today. “The cold-adapted species are amongst the most vulnerable animals and plants to ongoing climate change,” he stated.

During their investigation, the team compared evidence from plants and beetles with that from mammals, suggesting that some organisms may have evolved earlier in polar regions than previously thought. This revelation highlights the need for further research into how modern Arctic ecologies assembled, as it is unclear when and how animals and plants that inhabit this region came together.

The study found early occurrences of true lemmings and reindeer in the Arctic, which may have evolved as climates cooled during the early Pleistocene period. The polar bear and arctic fox, on the other hand, may have colonized from the South more recently, within the last 700,000 years. Some ice age cold species, like the woolly rhino, are distinct and may have evolved in steppe grasslands to the south, with their earliest occurrences in the Tibetan Plateau.

“This is the first concerted effort to compare the evolution of cold-adapted animals and plants since modern methods of palaeogenetics appeared,” Professor Stewart noted. “We can now build on these findings to understand more about how more cold-adapted species evolved and how the Arctic ecologies arose in the past, and use this knowledge to inform conservation efforts in the future.”