Tag Archives: lifes

We May Have Unraveled Many Mysteries of Life’s Origins

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Researchers have made significant progress in unraveling one of biology’s most profound puzzles: how the fundamental molecules of life came together over 4 billion years ago.

Proteins, composed of chains of amino acids, are pivotal to life, supporting tissue structure and performing countless functions within an organism. However, they lack the ability to self-replicate.

This task falls to RNAs, which serve as messengers and translators of genetic information in all living cells today.

The enigma lies in how these two distinct types of molecules first interacted, ultimately leading to the genetic code and the chain of events that produced us.

“RNA molecules transmit information between themselves in a highly predictable and efficient manner, but they struggle to communicate with the amino acids required for protein synthesis,” explains Senior Author of the study, Professor Matthew Powner told BBC Science Focus.

“For decades, the mechanisms and reasons behind the initial linkage of these two molecules have remained open questions.”

Previous laboratory attempts to replicate this chemistry faced challenges, as amino acids typically reacted with one another rather than with RNA, and unstable states in water hindered the reactions.

Adopting an innovative approach, the Powner team combined amino acids into a sulfur-containing compound called thioesters, a high-energy bond still utilized by cells today. This allowed for natural and selective reactions between the molecules and RNA.

Intriguingly, the inherent structure of RNA appears to direct amino acids to the proper position at the RNA strand’s edge.

Warm, nutrient-rich pools like those found in Yellowstone National Park today may have provided an ideal setting for these reactions to take place. – Credit: Getty

This suggests a viable chemical pathway through which fundamental processes in life began, without the necessity of more complex catalysts like enzymes.

“All these molecules were quite simple and likely present on the early Earth,” Powner noted.

The early ocean’s conditions would have been too limiting for these reactions to proceed, but nutrient-laden pools, ponds, and lakes offered an ideal environment.

This research also connects two longstanding theories: the “RNA world,” which emphasizes RNA’s crucial role, and the “thioester world,” which suggests high-energy thioesters were vital for early metabolism.

For Powner, the upcoming challenge is clear: he aims to “understand the origins of the universal genetic code of life.” This understanding could lead to insights on exactly how and where it originated on our planet.

“Scientists are constructing a validated framework that could lead to the creation of ‘cells’,’” Powner adds.

These cells not only have the potential to evolve but also to illuminate the origins of universal life structures and their organization.

“These reactions provide the crucial information needed to reasonably explore how and where life began on Earth.”

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About our experts

Matthew Powner is a professor of organic chemistry at the University of London. His work focuses on the chemistry related to life’s origins, and alongside his research group, he contributes to fields such as nucleic acid and amino oxidation, protometabolic networks, ribozymes, lipids, crystal engineering, green chemistry, catalysis, and photochemistry.

Source: www.sciencefocus.com

Recreating the Initial Steps of Life’s Evolution

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RNA is believed to have been crucial in the initiation of life

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The quest to decipher how dormant molecules might have sparked life brings researchers closer to their goal. A team has developed a method using partially replicable RNA molecules, suggesting that genuine self-replication could eventually be achieved.

RNA is a pivotal molecule in the discussion of life’s origins, as it can store information like DNA and catalyze reactions akin to proteins. While neither function is perfect on its own, the dual capability has led many scientists to theorize that life originated with self-replicating RNA molecules. “This was the molecule that governed biology,” says James Atwater from University College London.

Nonetheless, engineering self-replicating RNA molecules is a challenging task. RNA can form double helices similar to DNA, which can also be copied in a similar manner. By separating the two helices and adding RNA nucleotides to each strand, one could theoretically produce two identical helices. However, the binding between RNA strands is so strong that it complicates their separation for replication.

Recently, Attwater and his team found that a trio of RNA nucleotides (triplets) can be tightly bonded, preventing the strands from re-zipping. “Three is the sweet spot,” Attwater elaborates, noting that longer combinations are prone to errors. Thus, in their methodology, the team mixed RNA enzyme double helices with the triplet sequences.

By acidifying the solution and heating it to 80°C (176°F), the helices can be separated to allow for triplet pairing. When the solution is then made alkaline and cooled to -7°C (19°F), the highly concentrated liquid remaining as water freezes activates the RNA enzymes, which then bind the triplets together to form new strands.

Currently, researchers have succeeded in replicating RNA enzymes of up to 30 nucleotides in length from an original strand of 180 nucleotides. They believe that enhancing enzyme efficiency could lead to full replication.

Attwater highlights that this “very simple molecular system” possesses intriguing characteristics. One is the potential correlation between triplet RNA sequences and the triplet code that dictates protein sequences in modern cells. “There may be a connection between the biological mechanisms employed for RNA replication and the way RNA is utilized in present-day biology,” he explains.

Additionally, the team has identified that the triplet sequences most likely to facilitate replication exhibit the strongest bonding. This suggests that the earliest genetic code may have consisted of this set of triplets, which adds another layer of interest.

Researchers contend that the conditions required to support this process might naturally occur. Given the need for freshwater, it’s likely that such processes transpired on land within geothermal systems.

“The materials we see today can be found on Earth. Icelandic hot springs display a mixed pH, similar to what we use,” Attwater notes.

“RNA nucleotide triplets convey highly specific functional information in every cell,” remarks Zachary Adam from the University of Wisconsin-Madison. “This research is captivating as it may indicate a purely chemical role (rather than informational) for RNA nucleotide triplets that could predate the emergence of living cells.”

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Source: www.newscientist.com

The mystery of life’s origins on Earth: Unraveling the puzzle baffling scientists

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Life is abundant on Earth, from pigeons in the park to invisible microorganisms covering every surface. However, when Earth first formed 4.5 billion years ago, it was devoid of life. The question remains: how did the first life form emerge?

The answer is still unknown. If we understood the process, we could recreate it in a controlled environment. Scientists could replicate the right conditions with the right chemicals and potentially observe living organisms forming. Yet, this has never been accomplished before.

Although the exact origin of life remains a mystery, there are several clues that provide insight. Living organisms consist of various chemicals, including proteins and nucleic acids that carry genetic information. While these chemicals are complex, their basic building blocks are simple to create.

One of the first demonstrations of this concept came from chemist Stanley Miller in 1953. By simulating the early Earth’s conditions with water and gases, Miller produced amino acids, the fundamental components of proteins, through heating and electrical shocks resembling lightning.

Subsequent studies, such as one conducted by Sarah Simkuch, have shown how complex chemicals can arise from basic compounds. By starting with everyday chemicals like water and methane, researchers have generated thousands of substances found in living organisms.

While this abundance of chemical building blocks suggests a fertile environment for life to emerge, the transition from chemicals to life is not automatic. Several key factors contribute to the formation of life, including structure, sustenance, and reproduction.

As we all know, life requires proteins. Despite being complex chemicals, proteins form easily in nature © Getty Images

Research into the origin of life has focused on creating systems that encompass these essentials, such as genetic molecules capable of self-replication. However, the interdependence of these systems suggests a simultaneous emergence may be more plausible, possibly within confined spaces like deep-sea hydrothermal vents or terrestrial pools.

While the exact beginning of life remains uncertain, advancements in understanding have made the origin of life seem less inexplicable than before.

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Source: www.sciencefocus.com

What was the speed of life’s recovery from the end-Permian mass extinction?

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Think back to the last time you put together a puzzle. How long did it take you to connect the first piece? Did you aim for the edge pieces, or did you look for random pairs? Now imagine that the puzzle pieces are fossils of marine creatures that lived in ancient oceans. How would you put the pieces together? Which animals appeared first, and how long did they live for? This is the “puzzle” paleontologists face when studying the fossil record.

Researchers studying the fossil record have found that a mass extinction occurred at the end of the Permian Period 250 million years ago, leaving the oceans largely empty. They propose that the Earth's higher temperatures and changes in water chemistry killed 80% of marine life, ending the Paleozoic Era. Sometime later, during the Triassic Period, marine communities were reorganized to include a diversity of organisms similar to those found in today's oceans. As such, scientists believe that Triassic marine life is a precursor to modern marine ecosystems.

Paleontologists initially thought that marine animals recovered slowly from this extinction, because complex fossil ecosystems were only discovered 10 million years later. More recently, researchers have found diverse marine animal fossils just 3 million years after this mass extinction. However, these studies leave a gap of 3 million years between the mass extinction and the appearance of modern-like marine life in the earliest Triassic period.

An international team of researchers hypothesized that a collection of fossils in southern China called the Guiyang Biota could help fill in this gap: These ancient animals were covered in deep-sea sand, forming a layer of exceptionally well-preserved fossils, LagerstätteLagerstätten often form in calm undersea environments that can preserve delicate animal parts like bones and scales. Based on their location and their position within the rocks, the team proposed that the Guiyang fossils date to the Early Triassic period.

The scientists explained that the fossils at the site included animals across all five levels of the food chain, including 10 species of bony fish, two species of shrimp, lobsters, sponges, eels, and plankton. They found that fish ate lobsters, which ate clams, which ate plankton, which ate algae, which provided energy, forming a complete modern-day marine community. The scientists suggested that these fossils may be younger than the oldest diverse fossil ecosystem scientists have ever unearthed from the Early Triassic Period.

The researchers used three methods to determine the age of the Guiyang fossils: First, they looked at the eel-like creature's teeth. ConodontsThey only lived during certain periods in Earth's history, and the researchers found that conodont teeth from the southern China fossils belonged to Triassic conodonts, supporting their original dating estimates.

Second, the researchers measured chemical signals. Carbon isotopesfound in the rock walls surrounding the fossils. Scientists have measured carbon isotopes in rocks throughout Earth's history. By matching the increases and decreases in carbon isotopes in rocks to patterns of carbon isotopes from different periods in the rock record, researchers can estimate the age of the rocks. They found that the carbon isotopes in the Guiyang rocks matched the patterns of carbon isotopes in rocks from the Early Triassic Period, further supporting the Triassic age of the fossils.

Finally, the researchers needed to establish a precise age for the Guiyang rocks to determine how rapidly the fossil assemblage developed after the mass extinction event. They used a dating method based on the radioactive decay of uranium into lead. U-Pb datingIt is found in minerals extracted from two volcanic ash layers in the rock wall.

The team explained that these ash layers were located just below and just above the fossil layers in the rocks, meaning they fell just before and just after the fossils formed. U-Pb dating determined that the fossils were between 250.79 and 250.92 million years old. The team interpreted these dates as indicating that the marine creatures lived only 10,000 to 1 million years after their extinction 250 million years ago.

From the Triassic Lagerstätte fossils, the researchers concluded that marine ecosystems recovered quickly from the end-Permian extinction, re-establishing complete food chains within one million years of the mass extinction. The researchers propose that this diverse group of organisms thrived during a cold period in the warming Triassic environment. The researchers suggest that future researchers should examine whether a short period of cool weather allowed these organisms to survive the heat, or whether other factors, such as favorable ocean chemistry, were involved.


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Source: sciworthy.com

Improving the Outcomes of Life’s Big Choices: A Guide to Decision Making

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You could argue that LIFE is like a long game of blackjack. A common version of this is that each person is first dealt her two playing cards. The goal is to increase your hand to 21, or as close to this as possible without bursting. Players can either “stick” with their existing hand or “twist” it by requesting that they be dealt another card to add to their total. Of course, going over 21 risks being eliminated.

This may sound far from an everyday choice, but many of the most important decisions in our lives end up in dilemmas like this. Should I stay like this or should I take the plunge and move house? Should you keep your job or start your own business? Should you put up with an unsatisfactory relationship, or try your hand at love another time? In each case, we have to weigh the safety of what we have against riskier but potentially more valuable alternatives.

The uncertainty inherent in these dilemmas causes many of us to become paralyzed and stagnant in our analysis, ending up staying where we are and not giving ourselves a chance to win big. In contrast, some people are easily swayed by the lure of new things. They quickly turn to gambling until they lose everything due to impulsive behavior. If any of these scenarios sound familiar, help may be on the way. Thanks to a greater understanding of our underlying cognitive biases and how to escape them, we now have evidence-based strategies to think more rationally about these challenges, so we can put our lives on the line. Playing the game gives us the most benefit.

Source: www.newscientist.com

Comets are the most likely carriers of life’s essential building blocks to planets in clusters

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Nearby neighboring worlds can slow down the comet enough to allow the building blocks of life to survive

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It may be easiest to deliver materials for life to neighboring planets. Comets can carry many of the key building blocks of life, such as amino acids and other organic compounds, but their ability to deliver those building blocks to a particular planet depends on the configuration of their broader systems. It may depend.

There are several ideas about how the ingredients for life began on Earth, but the common idea is that a comet hit the Earth and organic molecules were deposited here. But comets tend to travel through space at extremely high speeds, and if they hit a planet at more than about 20 kilometers per second, the chances of their important compounds surviving the impact are almost zero.

Richard Anslow Researchers at the University of Cambridge ran a series of simulations to investigate how planetary systems can slow down comets and reduce their impact velocity enough to preserve these compounds. In ideal conditions, a slow impact would leave behind a type of prebiotic soup called a comet pond within the impact crater.

They discovered that there are two types of systems that can slow down a comet by 5 to 10 kilometers per second. One is a system with relatively massive stars, where everything tends to orbit slightly. For planets that are slow and have several planets spaced closely together like peas in a pod, the comet could weave between them and lose speed over time. there is.

“The best planetary systems are on relatively low-mass planets like Earth, around high-mass stars similar to the Sun but perhaps even more massive, and close enough for other rocky planets to pass through.” “It would be in a planetary system that has comets around it,” Anslow said.

He said that if astronomers eventually detect signs of life on other planets, simply examining the overall system configuration could help them understand how it got there. and that it could advance our limited understanding of how life formed. Earth.

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Source: www.newscientist.com