Table of Contents What If Earth Lost Oxygen for 5 Seconds? A Scientific Explanation Oxygen is a critical element for life on Earth, but what if the planet lost all its oxygen for just five seconds? It might not sound like a long time, but the consequences would be devastating. In just five seconds, every building on Earth would turn into dust, and life as we know it would be severely impacted. Here’s why. The Role of Oxygen in Earth’s Atmosphere Oxygen makes up about 21% of Earth’s atmosphere, and its presence is essential for many processes that support life. From the air we breathe to the structural integrity of objects and buildings, oxygen is everywhere, even where we don’t directly see it. Most importantly, oxygen is a key element in many chemical bonds that hold materials together, including the concrete, metal, and other building materials used in construction. Why Buildings Would Turn to Dust Without Oxygen Buildings, especially those made from concrete and metal, are held together by a variety of chemical bonds, many of which involve oxygen. Without oxygen, these bonds would instantly break apart. Concrete contains calcium carbonate, a material that depends on oxygen molecules. If oxygen were to disappear, the calcium carbonate would disintegrate, leaving buildings to collapse into dust in an instant. Similarly, metal structures would lose their oxidation layer that protects them from corrosion. This protective layer helps keep metals strong and stable. Without oxygen, metals would weaken and break apart, further contributing to the destruction of infrastructure. The Devastating Impact on Human Life The immediate collapse of buildings would not be the only catastrophe. The loss of oxygen would also disrupt air pressure and human biology. Sudden Drop in Air Pressure If oxygen were to vanish for five seconds, the air pressure would drop instantly. Oxygen contributes to about 21% of the atmospheric pressure, so its sudden absence would cause a dramatic pressure drop, similar to being at the top of a high-altitude mountain. This would cause humans’ inner ear to rupture, leading to excruciating pain and potential loss of hearing. Burning Skin and UV Radiation Without oxygen, there would be no ozone layer. The ozone layer, made of three oxygen molecules (O₃), acts as Earth’s sunscreen by blocking harmful ultraviolet (UV) rays from the sun. In just five seconds, without the protection of the ozone layer, humans would be exposed to severe

Table of Contents Understanding the Driving Forces of Evolution The forces that drive evolution have long been a subject of intense study. While traditional evolutionary theory places a significant emphasis on natural selection and random mutation as the primary mechanisms, emerging research suggests that the processes may be far more intricate than previously understood. In this article, we explore the deeper, less random dynamics at play in evolutionary biology, challenging the long-standing notion that evolution is purely the product of chance. Evolution Beyond Random Mutation: The Role of Non-Random Forces While random mutations are considered the raw material for evolution, recent studies have raised questions about how random these mutations truly are. Increasing evidence points to the fact that mutations may follow certain patterns, influenced by biological systems that control mutation rates and locations in the genome. This shifts the paradigm from viewing evolution as a completely random process to acknowledging that certain biases might direct genetic changes in ways that are not entirely random. Mutations and Genetic Repair Mechanisms Mutations, once believed to be entirely random, are now understood to be influenced by the organism’s ability to repair DNA. Cells have developed sophisticated DNA repair mechanisms that mitigate harmful mutations while allowing for variation that can drive adaptation. These repair processes reduce the randomness of mutations, suggesting a more directed form of evolutionary change. Non-Random Genetic Variation in Key Genes Research indicates that some genes are more prone to mutations than others, particularly those involved in immunity or adaptation to environmental pressures. These “hotspots” for genetic change are not distributed randomly across the genome, meaning that evolution could be channeled in specific directions. This insight introduces a controlled aspect to genetic variation, as it implies that some evolutionary changes are more likely to occur in response to environmental challenges. Natural Selection: More Than Survival of the Fittest Natural selection is often reduced to the simplistic notion of “survival of the fittest,” but this overlooks the complex interplay between genetics, environment, and fitness. Evolution is not simply a competition between individuals; it’s a multifaceted process that involves population dynamics, genetic drift, and the influence of ecosystem interactions. Genetic Drift and Population Bottlenecks Natural selection is not the only evolutionary force acting on populations. Genetic drift, a random process where certain traits become more common in a population due to chance events, plays a significant role, especially in small populations. Population

The Challenges of Space Exploration Space, an inherently hostile environment for humans, poses significant risks. Unprotected, a person can survive for no more than two minutes in a vacuum. The journey to space itself requires astronauts to be strapped to a controlled explosion of chemical propellants, underscoring the dangers involved. Since the first manned spaceflight in 1961, fewer than 700 people have made it to space. Companies like SpaceX and Blue Origin aim to change that, planning to send thousands of people into orbit. SpaceX has even begun taking bookings for orbital flights, marking the dawn of a new era in space exploration. Risks Associated with Space Travel Space travel is dangerous, as history reminds us. Two catastrophic shuttle disasters—Challenger in 1986 and Columbia in 2003—claimed the lives of 14 astronauts. In total, 30 astronauts and cosmonauts have died either during missions or in training. There have been countless close calls as well. For instance, two astronauts currently aboard the International Space Station (ISS) are staying an additional six months after NASA deemed their return vehicle, Boeing’s Starliner, unsafe. Technical issues, including a malfunctioning thruster, forced NASA to abandon Starliner as a safe re-entry vehicle. This incident is a stark reminder of the ongoing challenges in human space travel. On the ground, the risks are equally concerning. In 1967, three Apollo 1 astronauts tragically perished in a launch pad fire. Similarly, about 120 people died in a 1960 launchpad explosion of an unmanned rocket in Russia. One of the deadliest incidents occurred in 1996 when a Chinese rocket crashed into a village, claiming hundreds of lives. Despite these tragedies, the fatality rate for space travelers is about 3%. While this may seem low, it surpasses the risks associated with extreme sports like BASE jumping or wingsuit flying. Only activities like solo free-climbing or mountaineering at altitudes above 6,000 meters in the Himalayas pose a similar threat to life. The Rise of Civilian Space Travel The 2020s have ushered in the era of civilian astronauts. In the wake of the Challenger disaster, which claimed the life of schoolteacher Christa McAuliffe, NASA ceased sending civilians to space. However, private companies have embraced the idea, with SpaceX leading the charge. In 2021, SpaceX’s Inspiration 4 mission made history as the first all-civilian crew to reach orbit. Since 2020, 69 private astronauts have flown into space, with 46 crossing the Kármán line, the recognized

Billions of years ago, simple microbes laid the groundwork for the sophisticated immune systems found in complex organisms like humans. Recent findings from the University of Texas (UT) reveal that without these microscopic pioneers, our ability to combat viruses might have been significantly diminished. Originally, our planet was dominated by a diverse array of single-celled organisms, long before multicellular life came into existence. It was from these primordial life forms that complex life eventually emerged. In 2015, scientists discovered living descendants of these ancient microbes, known as a superphylum of archaea called Asgard, in ocean sediments between Greenland and Norway. By 2020, these Asgard archaea were cultivated in laboratories, marking a significant breakthrough in microbiology. Under the microscope, Asgard archaea resemble bacteria, yet they share a closer evolutionary relationship with eukaryotic life forms, such as plants and animals. The genomes of these archaea suggest that they diverged from our eukaryotic ancestors roughly 2 billion years ago, sparking the evolution of all complex life on Earth. The transition to complex organisms involved significant structural changes, including the development of a nucleus, potentially derived from a viral source which provided a protective enclosure known as a viral factory. Another critical development was the incorporation of mitochondria, likely acquired from engulfed bacterial predecessors. Despite the ancient nature of these microbes, our understanding of their defence mechanisms against bacteria and viruses remains limited. However, UT researchers have employed artificial intelligence to analyze newly expanded Asgard genomes, uncovering ancient immune defences that have evolved over millennia. One of the most striking discoveries is the identification of immune proteins similar to viperin, which are present in all complex life forms today and were likely inherited from the last common ancestor of archaea and eukaryotes. Viperin proteins combat viral infections by inhibiting viral replication, a vital defense mechanism shared across various life forms. Moreover, the research highlights that nearly 8 percent of the defence genes in Asgard archaea are linked to argonautes, another set of immune proteins. Argonautes help prevent viral spread by slicing up viral DNA, acting as a programmable immune system across different life domains. To further validate these findings, scientists cloned the genetic blueprints of viperin from Asgard archaea into E. coli bacteria. When exposed to viruses, the modified bacterial cells exhibited enhanced resistance, demonstrating the enduring impact of these ancient microbial defences. This ongoing research not only highlights the evolutionary continuity from microbes