About Life in Extreme Conditions

Rothschild claims that the harsh weather in 2014 might be classified as either chemically or physically. These environments could be sweltering, freezing, acidic, salty, or even have every state in a single ecosystem. Astrobiologists consider these regions to be harsh and severe. The majority of scholars also anticipate similar conditions on other worlds' unexplored ecosystems (Rothschild, 2001).
It has been demonstrated by recent study from the past century that life is not only feasible on Earth but also may live on other worlds and outside of our solar system. Several organisms have been known to survive under extreme conditions that were thought impossible or lethal for the survival of any living organism. Some living organisms exist under extreme conditions of pressure, drought, temperature, pH and salinity (Amills, 2007). These extreme conditions were previously thought to disrupt the cellular structure of living organisms when subjected to such hostile conditions. These plants and animals can be found on earth living in the above conditions. Organisms that are able to adapt and survive these harsh conditions are known as extremophiles. Extremophiles are from the three domains namely bacteria, archaea, and eucarya (Rothschild, 1994).

Ever since the discovery of hydrothermal vents on Galapagos Island, scientists and researchers have reconsidered their fundamental theory of life.. Extremophilic research has urged scientists to study beyond the earth borders and search for other life forms in the entire universe with adverse conditions (Prisco, 2007).

Extremophiles are believed to have existed for millions of years and led to the evolution of organisms. The evolution of life itself has been directly linked to extremophiles through several studies conducted by microbiologists. Even though they believe that earliest organisms on earth were hyperthermophiles, the theory is not accepted globally. The evidence of the past geochemical and geological conditions indicate suggest that the earth was hot for several million years because of the regular meteorite bombardments on the earth’s surface which were thought to cause heating of the environment up to about 100 degrees Celsius. Only hyperthermophiles would be able to survive such hot conditions. It is for this reason that there is a debate on the cold versus hot theory about the origin of life (Norton and Grant, 1988).

This paper discusses the extreme environments in a structured approach that will seek to describe an environment, illustrate its extremities, show examples and discuss more on how life forms are supported in this environments.

Imagine an area where dehydrations tolls reach to over 70 %.This means that lipids commonly known as fats, proteins and nucleic acids RNA and DNA in animals and plants are structurally destroyed and damaged. Plants will rapidly wilt out while animals die in splits of seconds (Enviromesists, 2013).

Dry environments range from either too cold or too hot. In cold environments, the temperatures are ice cold and lead to instant freezing. Water absorption and intake are hindered, and body temperatures lowered to below survival limits. On earth, the Antarctic dry valleys are the known coldest and driest places ever (Raj, 2012). Here temperatures are way below -17 degrees Celsius. Other kinds of such ecosystems are found on mountain tops as on Mount Everest where any water droplets will freeze at an instance, ocean beds where no sunlight reaches are dark and very cold. In such areas, the precipitation levels are very low. In this extreme cold environments, extremophiles that survive here face challenges of low precipitation, the risk of freezing and live to tell a life to tell, slow biological reactions and risk of enzyme failure.



Figure 1: A photo of the surface of Mars with eroded surface.



Adaptations are improvised to push them to the survival limits. These are stressful reactions targeted to ensure existence. In such areas the soils are poor, and water intake by plants is limited greatly. Plants are thorny like so as to ensure minimal water loss too (Morange et al., 2014).

Planets as Pluto are known to be freezing owing to the existence of methane and nitrogen gases. On the surface of Pluto, according to Pat Rowlings of National Aeronautics Space Agency (NASA), the surface of Pluto is characterized by high-temperature shifts and changes, terrestrial stresses and compressional stresses which lead to dry liquefied underground oceans in Pluto. Such an environment can theoretically support life forms that exist on earth as the thorn algae which exist as a single streak of the node.

Hot environments on the other hand have high temperatures prevailing to over 40 degrees Celsius and persisting. Some of the known hottest and driest areas on earth are the Atacama Desert in the Andean plains in Chile. This is also one of the oldest regions believed to be on earth. The area is also known to have some of the highest dehydration rates of over 79 %( Tinto, 2011).In these environments, plants lose water at extreme rates than the absorption rate, proteins and lipids are broken into lifeless forms rendering the organism dead, such is called denaturation. In the Atacama Desert, the Pompeii worm is one of the organisms known to be surviving. It is, in fact, the world's known tolerant organism that can survive in over 153 degrees Celsius temperature variations as well as without water for over the years (Littlejohn, 2004).The worm has adaptive capabilities that allow it to survive; such are like a covered feathered bodies, secretion of mucus to cushion against heat and such extremities.



Figure 2: A deep ocean hydrothermal vent belching sulfide-rich hot water.

Known organisms to surviving in extremely dry areas are algae, lichens, fungi, bacteria, Insects and yeasts which are anhydrobiotic and have a high stressful response.

With a variance of the conditions, it is possible for the survival of organisms in other extraterrestrial ecosystems. An organism as the Pompeii worm is believed that can survive within the limits of the rigid planet Mars (Madigan, 1997) where the surface temperatures are about -50 degrees to 70 degrees. Mars temperatures vary due to changing thermal blanket thus the rigidity and shifts. The known form of algae can adapt basing to the ability to shift temperature requirements as they do in the dry, hot regions on earth. This owes to its ability to peacefully survive in harsh environments on earth.

Salt concentrations are varied based on ecosystemic evolutions and states. In this environment, the concentration of salt is higher than that of sea water. This can be higher than 3.5 %( Cary, 1997).In the world, the great salt lake in Mexico is known to be one of the most saline environments, but still, life forms are supported. Extremophiles as microbes are known to use pigments called centroids that help cushion them against the effects of salinity on their bodies. They are able to intake required ration of water from such environments. Increased salinity can cause structural diversions in organisms leading to instant death and destruction of RNA and DNA materials in the body.



Figure 3: Octopus hot spring found in Yellowstone National park known to have a pH of 8.8

In extraterrestrial scopes, the moon Callisto, on Jupiter is known to have a weak magnetic field around it which is clear evidence that there exist salty water amounts on Jupiter’s surface. These are clear indication that salinity might be high thus need for adaptability to such areas. Microbes as in the saline environments of the earth may as well cope up, adapt and survive on Jupiter (Fuller, lane and Benson, 2004).

Radiation which is the exposure to harmful rays, as well as waves, causes the harmful and dangerous effect to organisms. On earth, even the sunlight, a natural cause of radiation, can cause conditions to humans and animals without control mechanisms called Xeroderma Pigmentora which means exposure to sunlight may render them dead. Radiation infested environments vary from natural to those caused by human activities as bombings (Horikoshi, 2008).

In such areas, despite the effects know to be existing, we have organisms as the rubrobacter, and deinococcus bacteria which can even survive up to 20KGy gamma radiation levels and green algae can survive (Vreeland, Rosenzweig and Powers, 2000).

On Mars, rock blasting activities and closeness to the sun are known to cause high radiation effects and presence on the Mars. There is high existence of Ultra violet rays. As such life is known to be unbearable and harsh but as discussed, there might be chances of survival of radiation persisting organisms on planet Mars

On earth presence of liquid water is determined by temperature variations. Low temperatures lead to slow enzymatic activity and membrane fluid decrease while hot temperatures can cause high denaturation and destruction of DNA and RNA structures in organisms. Temperature shifts in ecosystems may result from high humidities, human activities, and natural calamities (Macelroy, 1974).

Most known areas in the world to be hot are the Geysers, hot springs, and Fumaroles. In such areas, there is decreased solubility of gasses. This means that organisms that need to survive here need to have a capability to consume gases for survival in extremely limited environments. Such organisms are known as hyperthermophiles. Such are mostly from the group archaea and bacteria as eubacteria.

Some of the hottest areas on earth are the Yellowstone hot spring where the temperatures are as high as 95 degrees Celsius.

On planet Venus, the atmosphere is largely surrounded by a layer of gasses mostly carbon dioxide which can highly support bacteria and archaea life forms but temperatures are too high hence gaseous solubility is very minimal but as per illustration on survivability in extreme conditions, chances are that some families of bacteria may be on Venus (Fischer and Kohl, 2010).

In the deep oceans beds, it is very dark and temperatures very cold. Also in the earth Polar Regions the temperatures are very low to even below -20 degrees which mean organisms like microbes and ocean turtles have to adapt and gain stress responses to survive in such

On planet Saturn, the ring of moons causes the formation of high tidal results that shifts ocean beds and causing increased depths of the oceans and reduces freezing masses on the oceans. These tidal waves are known to result into chemical fusions that can lead to archea like organisms. This is a theoretical oversight that organisms can survive on Planet Saturn.

Acidity and alkalinity are the measures of the concentration of protons in an area or environment. The pH scale ranging from 1 to 14 is used to measure the level of acidity and level of alkalinity. The lower the pH value i.e. towards 1, the higher the acidity while the higher the value, the higher the alkalinity. Acidity ranges from level zero to 6, while level 7 is neutral where the most biological processes are supported, and level 8 to 14 are for alkalinity.

In extreme areas, activities as photosynthesis and cytoplasmic activities are largely affected by PH (Amills, 2007). Organisms that mostly survive in low PH environments are mostly known as acidophiles i.e. acid lovers. Organisms as fish, insects, might not survive even extreme conditions based on PH scale at level PH 4.At scale of PH 1 and 0, organisms as algae can survive. The red alga and the green alga (Dunaliella acidophilus) can survive at PH level 1.That is very extreme.

The Yellowstone National Park is known for having the world most bubbling and hot springs (Seckbach, 2011).

On planet Venus, there exist tremendous volcanic activities and so is on the earth’s moon surface. The existence of volcanic activities is known to result in acidic and alkaline materials surfacing. With such comes organisms and ecosystems that need to survive as well as support life. With such, it is possible for organisms as algae to survive.



























References

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