New research from the laboratory of Harvard Medical School has suggested that microbes may have lived underground for over a billion years.
Dating from the Mesolithic age, this research was led by Professor Salvatore De Laurentiis and his team. The study involved the analysis of cores from nine caves in southwestern Italy which had yielded floras consistent with a terrestrial environment. Other areas of Europe and North America also yielded signs of microbial activity in cavities drilled from cliff sides, slopes, and other landscapes which suggest that these organisms have occupied the surfaces of these landscapes for many billions of years.
Is it possible that microbes may have lived underground for over a billion years?
This would make the most sense if you believe the Earth is only a few million years old. If you think the Earth is much older, you might be surprised to learn that microbes have been living in the limestone and other rock surfaces of our planet for several million years. It seems amazing that microbes would have stayed underground for this long without being affected by modern society made pollutants.
Why did microbes remain so long buried?
Evidence suggests that microbes may have lived underground for a few million years simply because they were not able to adapt to modern life. The oxygen rich upper atmosphere of the Earth prevented microbes from evolving to a bony form like animals and insects do. This is why the fossils we see today all have a bony covering. Evidence also shows that microbes may have lived underground for millions of years before the appearance of modern man.
Where did microbes live during the eras of ancient earth?
Archaeologists have found microbes in numerous archeological sites around the world. They are mostly around 10 feet below the surface. The question many scientists are asking is how did these microbes get to the surface?
How did the first humans come across ancient microbes?
During the early days of human civilization, when food was scarce, people developed fire to cook food. Somewhere along the way, some smart people realized that they could use fire to kill off some of the microbes that were already living in the nooks and crannies of the ancient cave dwellings. Soon thereafter, these microbes began to multiply and grow in number. These microbes became known as bacteria. They fed on the oxygen rich air, which was in plentiful in those times. With time, the bacteria started to grow and divide until there was enough of them to infect many other locations in the environment and begin to cause a variety of ecological problems.
In order to understand how did microbes get to the surface, it is necessary to look at how did the ancient people perceive the world around them. Ancient people had to look to the stars in the night sky to determine what the day’s activities were. Many people believe that if the microbes that were responsible for causing the death of the dinosaurs were still alive today, they would have surely killed the dinosaurs. Therefore, understanding how did microbes live underground during the eras of ancient earth is necessary in order to understand how did our modern day microbes come about.
Looking back through the ages, we can see evidence of microbial life forms dating back to prehistoric times. Some evidences have been found in such places as amber, rock, soil, rocks, wood, and shells dating from the Paleolithic period or before. Evidence of microbial activity can also be detected in the form of fossilized bacteria.
Microbes play an important role in nature by serving as a major supplier to the food chain. They also help to break down dead plant matter, as well as make it available for other creatures to consume. It has been estimated that microbes alone account for more than 65% of the Earth’s total land mass. They can be found in soils, rocks, and fossilized bacteria. As we continue to look back in prehistoric times, we can see a correlation between life and how the environment was formed.
Through the ages, the microbes that we find have appeared to have developed into different species. As new species of microbes are developed, the older ones may have been Extinct. This is good news as this allows scientists to learn about the history of the Earth and search for signs of microbial life on other planets.
If microbes did live underground for the duration of the Earth’s history, we may be able to find signs of life on Mars. Who knows?
Studying the Bacterial and Xenometabolite Mapping Through Microbial mats
We already know about the basic species of bacteria and fungi that populated the Earth’s surface millions of years ago. These so-called prehistoric microbes produced enzymes and other molecules necessary for their existence. Then, some unknown organisms began to populate the planet, including those that produce sulfur and other xenometabolites. The older species were methanogens – simple sulfur producers – while the newer ones were anaerobes, those that produce oxygen and other compounds. The latest species are the methanogens that are most common today.
When gut microbes first colonized the human body, they did so in a relatively small volume. The human gut has only a few times the volume of the earth’s atmosphere. But, surprisingly, these microbial communities began to multiply and dominate the human body when it became much polluted with other types of pollutants. This is the latest of the microbe origins stories.
Over the last decade or so, we have learned a great deal about the origin of life on earth. Part of this has been brought about by the sequencing of DNA from living organisms. Another piece of the puzzle has come from the study of the metalloprotein life form called Vibrio. One of its closest relatives is the pathogen called Footborne Pathogen 24. It was found to be present in the urine of healthy humans, indicating that it was one of the first microbes to colonize the human body and to use the urinary tract as a source of food.
In addition, we now know that several strains of the Vibrio species are associated with allergic reactions and other immune dysfunctions.
Thus, understanding the whole microbe origins story involves investigating how and when these organisms colonize and survive. We know that methanogens metabolize glucose to energy. Some have even been seen to secrete insulin from their exoskeletons. The biggest question that remains is whether or not these enzymes are involved in the uptake of other alien metabolisms. To answer this question, we need to look deeper into the role of xenometabolites and methanogens.
The first microbes to colonize the human gut were methanogens. The earliest evidence suggests that these methanogens, which include Chlorophyll and other green plants, were responsible for the colonization of the GI tract. These organisms would have acted as a diversifier, drawing in some of the non-bacteria cells that would later form the first gut flora.
It was later that the xenobacteria colonized the gut. They appear to have acted as a co-balance between the probiotics that populated the gut and potentially dangerous ones that are detrimental to health. The relationship between these two microbial communities is the key to understand the whole microbe origins story. Interestingly, it was an experiment conducted in Germany that provided the first evidence.
Subsequent studies focused on analyzing the fossil record from the early Earth and inferred that the diversity of microbes in the early Earth and the diversity that persist to this day are the result of the adoption of microbial mats by several marine species. This study also indicated that the mats eventually became a significant portion of the ocean’s organic inventory. Evidence from the cores contained within the cores indicate that microbial mats contributed up to three quarters of the Earth’s organic inventory, indicating their vital importance in the evolution of life on Earth.
The study suggests that the mats may also play a role in the origins of life on Earth. Alternatively, they could act as a vehicle for the transportation of alien putative xenometabolites. It is currently unclear how the foreign microbes enter the host genome. The study is an important first step in understanding the true diversity of microbial mats and their role in the Earth’s origins and metabolism.
Provided by Antonio Westley
Disclaimer: This article is meant to be seen as an overview of this subject and not a reflection of viewpoints or opinions as nothing is definitive. So, make sure to do your research and feel free to use this information at your own discretion.