Well, we’ve fallen quite far behind with our postings. We’re currently out on the Olympic peninsula in Washington, and three parks removed from Yellowstone. It may be hard to believe but we continue to find ourselves in a time crunch to get the writing done. We’re either hiking or traveling and that makes it hard to find time to sit down at the computer. Well, time to catch up.

Yellowstone, as expected, was extremely crowded. If you didn’t get to viewing locations early in the morning you had to deal with mob scenes of tourists, and that’s if you were even lucky enough to get a parking space. We waited in line for four hours to get a campsite, after arriving at 6:30 AM to get in line! This would be a great park to visit in September, after families are off vacation and the kids are back in school.

That being said, it is an amazing park. It runs to the north of Grand Teton National Park and is continuous with it. It’s no surprise then that much of the flora and fauna is similar. There are Bison, moose, elk, deer, marmots, as well as many other small mammals, birds, and flowers. What isn’t the same are the geo-thermal attractions, which are astounding. It is a geo-thermal, earth science, paradise. From the geysers, hot springs, steam vents, and mud pots, it is truly a scene from a distant planet. What causes all these features is the close proximity of molten magma underneath the ground but close to the surface. Close to the surface is about 8 miles below. That may seem far but that is closer than most of the rest of the planet. The heat from that magma is what superheats the water that seeps down from the surface, causes pressure to build and geysers to spout. The centerpiece of Yellowstone is the middle of the park, which forms a caldera. This is a sunken area about 40 by 35 miles in size that is actually the location of the last volcanic eruption from below that occurred about 640,000 years ago. The level of the ground here actually fluctuates in height based on the upward pressure of the magma below! This caldera is where almost all of the geo-thermal features are located and where the magma below is closest to the surface. The caldera is continuously monitored by scientists as a future eruption is certainly possible.

As with all ecosystems, the abiotic features have a direct impact on the biotic and nowhere more so than in Yellowstone. The heat from the geysers, steam vents, mud pots, and hot springs allow grasses and other plants to grow throughout the year, including the winter. The air stays warm around these area’s and the ground free of snow. This unique area of the caldera is quite different than the surrounding land of Wyoming and Montana where the snow is deep and the winters frigid. That warmth and plant growth is what attracts grazing animals to the area like Elk, Deer, Bison, and other small mammals who come to take advantage of the warmth and the food. These animals in turn attract predators like coyotes and wolves. The predators chase the grazers who eventually run out of the caldera and into deep snow where they bog down and become the next meal. Ephydrid Flies live out there life cycle around the hot springs and are food for spiders, dragonflies, and other predatory insects.

The most amazing life however in Yellowstone are the microbes. The geo-thermal magnificence of this park causes many visitors to overlook the microbes. However, they are the source of not only many of its physical features, but also of its amazing colors. Additionally, they are truly unique among the microbes of our planet. There are very few places outside of this park and very few microbes that are able to live in boiling water or in boiling water that is also a strong acid. These amazing microbes not only live in these extreme environments, they thrive in them. So much so that normally you would need a microscope to see them, but here, they can grow in thick mats or sheets of feather like filaments that are visible to the naked eye. The microbes found in these environments include the Archaea which are the ancient bacteria. These are thought to be the first cellular organisms to appear on earth. Since early earth was not a place you would want to vacation to, (toxic atmosphere, super hot, lightening strikes, massive volcanic activity, etc.), it makes sense that these microbes would live today in an extreme environment similar to those early days of our planet. Thus, we give them the name “extremophiles”. Lovers of the extreme. The most extreme of the environments in Yellowstone are occupied by the Archaea. The microbes found here also include bacteria, eukaryotic cells, and protists. The more moderate environments are occupied by the bacteria. As most of us know, the Archaea and Bacteria lack a nucleus. The Eukaryotes, like the protists, have a nucleus and include different types of algae that thrive in the cooler waters.

Although these unique single celled organisms share the same neighborhood, there are significant differences between them. Some can live in water of temperatures that exceed 250 degree’s farenheight. Others can only tolerate water temperatures in the 90 degree range. Some live in waters with a pH of 2, which is similar to battery acid! Others live in environments with a pH of 8 or 9. They also differ from each other in their manner of metabolism. Some are photoautotrophs, using light as a source of energy and inorganic carbon for making organic molecules. Others are chemoautotrophs, using chemicals like H2S (hydrogen sulfide) as a source of energy in combination with inorganic carbon. H2S is a toxic gas that smells like rotten eggs due to the sulfur. Some metabolize the H2S and turn it into sulfuric acid (H2SO4)! Some of these organisms carry out a type of photosynthesis that does not produce oxygen. Instead, their waste product of this process is sulfate! The organisms here also include an algae called Rhodophyta, which is the most heat and acid tolerant algae we know of. Some use the toxic substance arsenic as a source of energy! Some use pyrite (fools gold) in the absence of oxygen as a source of energy. Some do photosynthesis during the day and then switch to fermentation at night. These are some of the most unique organisms found on planet earth and it is estimated that scientists have only uncovered 1% of this amazing microbial diversity that exists in the Yellowstone thermal features!

The colors in Yellowstone’s thermal features are also due to the minerals and microbes that live there. In general, yellow colors are due to sulfur compounds and organisms that utilize sulfur compounds in their metabolism. Dark brown/red and rust colored features usually contain iron compounds and again, organisms that utilize iron in their metabolism. Green is usually due to photosynthetic algae. Milky blue pools are due to high concentrations of silica, which is the substance used to make glass. In general, waters that are green or brown contain organisms living in the cooler waters, while waters that are orange or yellow contain organisms living in hotter or even boiling water.

In and of itself, this incredible diversity is something to behold with wonder and awe. These diverse microbes also have powerful and practical applications. Consider the following:

*These extremophiles are providing scientists who are searching for life on other planets with a signature of what to look for and what that life may look like. Not all alien life is expected to look like ET.

*Some are being investigated as an alternative fuel source as they can take chemical compounds and produce hydrogen gas which is a clean burning fuel.

*Some are being used to break down toxic pesticides that pollute our waterways and soil.

*An enzyme has been isolated from one that is being used in gene therapy and genome engineering. It has also been shown to cleave viral DNA.

*Some produce toxins that are being tested as a potential treatment for cancerous tumors.

*The enzyme Taq polymerase is used in the Polymerase Chain Reaction (methodology for making copies of DNA that is used in paternity testing and crime scene studies). This enzyme was isolated in 1968 from the bacteria Thermus aquaticus.

All of this from just 1% of the microbial species identified so far!

There are also some compelling questions that arise when studying these little guys that could lead to other significant discoveries. For instance, the metabolism of living things is mediated by enzymes and most enzymes are proteins. A proteins activity is dependent on the shape it takes. Exposure to extreme heat and or pH denatures most proteins, rendering them unable to control the reactions they are meant to mediate. What is it about the enzymes in these extremophiles that allows them to disregard these high temperatures and low pH and still function effectively? In addition, all cells have a cell membrane and cell membranes consist of lipids (fats). Fats dissolve at high temps and low pH but not these guys. Why? These questions are currently being researched but undoubtedly will provide scientists with understandings whose applications could be significant.

I won’t miss the crowds when we go, but I will miss the microbes! It was a truly unique experience to see and learn so much about these organisms that we are only beginning to understand.