What is the relationship between archaea and fumaroles

Halophilic Archaea determined from geothermal steam vent aerosols.

What are the evolutionary relationships between the Archaea and the other two domains of life? What was the nature of the last archaeal ancestor? When did. The Archaea comprise a group of single-celled microorganisms that, like bacteria , tree showing the relationship between the archaea and other forms of life. Thus, in spite of the extreme heat of fumarole steam, the .. strongly supported nodes important for understanding the relationships of the clone sequences to.

Chemical traces of ancient organisms are called molecular fossils, and include a wide variety of chemical substances. Ideally, a molecular fossil should be a chemical compound that 1 is found in just one group of organisms, 2 is not prone to chemical decay, or 3 decays into predictable and recognizable secondary chemicals. In the case of the Archaea, there is a very good candidate to preserve as a molecular fossil from the cell membrane. Archeal membranes do not contain the same lipids oily compounds that other organisms do; instead, their membranes are formed from isoprene chains.

Because these particular isoprene structures are unique to archaeans, and because they are not as prone to decomposition at high temperatures, they make good markers for the presence of ancient Archaea. These are Miocene desposits whose geologic history is well known. Material from the shale was dissolved and analyzed using a combination of chromatography and mass spectrometry.

These processes work by separating compounds by weight and other properties, and produce a "chemical fingerprint". The fingerprint of the Messel shale included isoprene compounds identical to those found in some archaeans.

Fossil Record of the Archaea

Based on the geologic history of the Messel area, thermophiles and halophiles are not likely to have ever lived there, so the most likely culprits to have left these chemical fingerprints behind are archaeal methanogens methane-producers. Their chemical traces have even been found in sediments from the Isua district of west Greenland, the oldest known sediments on Earth at about 3.

This means that the Archaea and life in general appeared on Earth within one billion years of the planet's formation, and at a time when conditions were still quite inhospitable for life as we usually think of it. The atmosphere of the young Earth was rich in ammonia and methane, and was probably very hot. Such conditions, while toxic to plants and animals, can be quite cozy for archaeans. Rather than being oddball organisms evolved to survive in unusual conditions, the Archaea may represent remnants of once-thriving communities that dominated the world when it was young.

Get a general introduction to the major groups of prokaryotes from Kenneth Todar at the University of Wisconsin--Madison.

  • Introduction to the Archaea

At left is Octopus Spring, and at right is Obsidian Pool. Each pool has slightly different mineral content, temperature, salinity, etc. The biologists pictured above are immersing microscope slides in the boiling pool onto which some archaeans might be captured for study. Archaeans include inhabitants of some of the most extreme environments on the planet.

Some live near rift vents in the deep sea at temperatures well over degrees Centigrade. Others live in hot springs such as the ones pictured aboveor in extremely alkaline or acid waters. They have been found thriving inside the digestive tracts of cows, termites, and marine life where they produce methane.

They live in the anoxic muds of marshes and at the bottom of the ocean, and even thrive in petroleum deposits deep underground.

Thermophile Meaning

Some archaeans can survive the dessicating effects of extremely saline waters. One salt-loving group of archaea includes Halobacterium, a well-studied archaean. The light-sensitive pigment bacteriorhodopsin gives Halobacterium its color and provides it with chemical energy. Bacteriorhodopsin has a lovely purple color and it pumps protons to the outside of the membrane.

When these protons flow back, they are used in the synthesis of ATP, which is the energy source of the cell. This protein is chemically very similar to the light-detecting pigment rhodopsin, found in the vertebrate retina. Archaeans may be the only organisms that can live in extreme habitats such as thermal vents or hypersaline water.

They may be extremely abundant in environments that are hostile to all other life forms. However, archaeans are not restricted to extreme environments; new research is showing that archaeans are also quite abundant in the plankton of the open sea. Much is still to be learned about these microbes, but it is clear that the Archaea is a remarkably diverse and successful clade of organisms.

Halophilic Archaea determined from geothermal steam vent aerosols.

Click on the four buttons below to learn more about the Archaea. For even more archaeal information: An impressive set of links to all things Archaean may be found at Life in Extreme Environments: Archaea on the Astrobiology Web.

Get a general introduction to the major groups of prokaryotes from Kenneth Todar at the University of Wisconsin--Madison.