The desert is home to all kinds of living things, from insects to mammals to bacteria. Bacteria found in the desert, however, is quite different to bacteria found in other environments. It has adapted to live under less than optimal conditions, surviving without water, shade, or interaction with other species.
One unique type of bacteria found in the desert is the so called "desert varnish," a type of fungus that can turn desert rocks all shades of green, orange, and yellow. This type of bacteria is believed to be one of the oldest living organisms on Earth. Through thousands of years, bacteria living in the desert have mixed with the manganese oxide that occurs naturally on the rocks, resulting in a patina that now covers many desert rocks. While this should naturally result in a brownish tint, the effect of the sun and erosion often give way to a bright collection of colors. Since it takes about 10,000 years for a varnish to cover a portion of rock, the bacteria naturally evolves to adapt to changes in the environment.
Another the of bacteria found in the desert is lichens, a mix of fungus and algal cells. The desert may seem a strange place for algae to grow, but the truth is that these microorganisms have adapted to live in almost every type of environment on Earth. In the desert, algae can survive due to a symbiotic connection with fungal filaments. Algae got to the area about 14,000 years ago, when glaciers covered part of what is now the desert.
Clay is often found mixed with bacteria in the desert. This is because winds blow the clay in from nearby areas, allowing the bacteria to mix with it, forming a rather sticky varnish that adheres to rocks easily. In 2005, a new type of desert bacteria surprised scientists worldwide. The previously-unknown species can produce methane, the same element found in Mars environment. This leads scientists to believe Mars may be home to bacteria and other small living organisms.
