What fossil evidence exists for bacteria? How do scientists know bacteria
existed 3.5 BYA? Include examples of the evidence they have. (Hint: look up stromatolites)
What fossil evidence exists for bacteria? How do scientists know bacteria existed 3.5 BYA? Include examples of the evidence they have.
Scientists discovered traces of bacteria that lived 3.40 billion years ago in Australian rocks. Finding these remnants of bacteria fossils required hard look at some of the planet’s oldest rocks, located in Western Australia’s Pilbara region (Health and Science, 2013.) There are older rocks on Earth, said Maud Walsh, a biogeologist at Louisiana State University in Baton Rouge. “But these are the best-preserved sedimentary rocks we know of, the ones most likely to preserve the really tiny structures and chemicals that provide evidence for life.” (Maud Walsh, 2013)
Bacteria that can get their energy form sulphur instead of oxygen are abundant in volcanic environments today, and scientists had recently found rocks containing possible chemical evidence that sulphur-metabolizing bacteria existed almost 3.5 billion years ago. The recent discovery in the Strelley Pool rock formation demonstrates the first fossils backing up the sulphur evidence. The fossils were found in rocks that were originally formed in shallow seas near a coastline and suggest that beaches may have been the key habitat where the Earth's first lifeforms thrived, said David Wacey, of the University of Western Australia (CBC News, 2013.)
Stromatolites are not only the Earth’s oldest fossils but they are portals to the Earth’s past. Stromatolites are fossil evidence of the prokaryotic life (bacteria) that remains today. The prokaryotes are the ones who make the biosphere a habitable place for living organisms. In other words strimatolites are sedimentary fossils formed from layers of cyanobacteria, calcium carbonate, and trapped sediment (Virtual Fossil Museum, 2002-2013.)
In 1996, scientists announced the evidence of what is said to be bacterial fossils in meteorites. This evidence has been found in the 1931 Tatahouine meteorite and the Martian meteorite, found in Antarctica. Oval and rod forms have been found in the surface of the Martian meteorite, which are believed to be the bacteria fossil. After several analyses like scanning and transmission electron microscopy, NASA found magnetite crystals, which are the remnants of bacteria (MicrobeWiki, August 13, 2013.)
• Health and Science, 2013 http://www.washingtonpost.com/national/health-science/bacterial-traces-from-35-billion-years-ago-are-oldest-fossils-experts-say/2012/12/27/9261e02c-4acb-11e2-9a42-d1ce6d0ed278_story.html
• Bacterial Fossils in Meteorites August 13, 2o13 http://microbewiki.kenyon.edu/index.php/Bacterial_Fossils_in_Meteorites
• Virtual Fossil Museum (2002-2013) http://www.fossilmuseum.net/Tree_of_Life/Stromatolites.htm
What fossil evidence exists for bacteria? How do scientists know bacteria existed 3.5 BYA? Include examples of the evidence they have.
It really is shocking that fossils leave bacteria. Yet, one certain group of bacteria, the cyanobacteria or "blue-green algae," have left a fossil record that spreads far back into the Precambrian - the oldest cyanobacteria-like fossils known are nearly 3.5 billion years old, among the oldest fossils currently known. Cyanobacteria are bigger than most bacteria, and may hide a thick cell wall. Cyanobacteria can form large layered structures, called stromatolites (if more or less dome-shaped) or oncolites (if round). They form as a mat of cyanobacteria grows in a water location, catching sediment and sometimes hiding calcium carbonate. When they are divided very finely, fossil stromatolites can be found to have beautifully conserved fossil cyanobacteria and algae.
The conserved cell walls of bacteria that lived in oceans without oxygen 3.4 billion years ago are thought to be the oldest fossils ever found. The tiny fossils were found in Western Australia among bands of covered rock 3.3 billion to 3.5 billion years old. The fossils were surrounded in a sandstone layer from a shallow-water beach that represents one of the Earth’s first conserved coastlines. Scientists know that bacteria have existed since 3.5 BCY from 1996. Headings dispersed when scientists said the sign of what is demanded to be bacterial fossils in meteorites. The scientists found the bacteria with oval forms and evidence shows that it is bacteria. Sources: http://www.ucmp.berkeley.edu/b http://www.cbc.ca/news/technology/oldest-fossils-reveal-life-3-4-billion-years-ago-1.978460 acteria/bacteriafr.html http://microbewiki.kenyon.edu/index.php/Bacterial_Fossils_in_Meteorites
What are fossils? A fossil is the remains of a prehistoric plant or animal embedded in rock and preserved in petrified form. Fossils have been here, in this planet, around 3.5 Billions of years. I will be explaining how scientists know that fossils existed so long ago and what fossil evidence exists for bacteria.
The fossil evidence that exists from bacteria is far back into the Precambrian Era. There is one particular bacteria type that has left more fossils than any other type, it is called the cyanobacteria or "blue-green algae”. The Cyanobacteria is one of the largest bacteria there is, it also may form large layered structures called stromatolites (if more or less dome-shaped) or oncolites (if round). When fossils are very thin, fossil stromatolites may be found to contain exquisitely preserved fossil cyanobacteria and algae(1).
“In a sun-scorched region of Western Australia known as Pilbara, a team of American and Australian paleobiologists believe they have located the oldest known evidence of life on Earth. The ancient bacterial fossils have been dated as 3.49 billion years old, only about a billion years after scientists estimate the Earth was formed. According to the findings presented by the joint team at the most recent meeting of the Geological Society of America, the tiny ridges that lattice the rocks like a fishing net seem to indicate that primitive bacteria integrated themselves into expansive networks. This collective behavior, which mirrors that of modern bacteria, involved thousands of different bacteria species, each performing a unique task that contributed to the larger community”(2)
How do scientists know that fossils existed so long ago? It’s hard to tell if I should believe scientists that fossils really exist and that they really are that old, so I’m going to explain how they date fossils. First of all scientists don’t just look at it and determine what age they are. They first have to combine a series of techniques that they use to find the age of the fossil. The use Relative dating—that is when fossils are found in sedimentary rocks that formed when eroded sediments piled up in low-lying places such as river flood plains, lake bottoms or ocean floors(3). Then they use Radiometric Dating— after scientists learned that the nuclear decay of radioactive elements takes place at a predictable rate, they realized that the traces of radioactive elements present in certain types of rock, such as hardened lava and tuff (formed from compacted volcanic ash), could be analyzed chemically to determine the ages, in years, of those rocks(3). Last they put the two things together and then once it was possible to measure the ages of volcanic layers in a stack of sedimentary rock, the entire sequence could be pinned to the absolute time scale (3).
Resources: 1.Bacteria: Fossil Record http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html
2.redOrbit; January 2, 2013 http://www.redorbit.com/news/science/1112756338/oldest-fossils-on-earth-010213/
3.How do we know the ages of fossils and fossil-bearing rocks? http://www.mnh.si.edu/exhibits/backyard-dinosaurs/questions-answers.cfm?know=a24
Fossil evidence is that something has been found a long time ago that can proof something. Such as fossils now we know that dinosaurs existed before us and now we are sure of it we can also say how long it was. Same can be said for bacteria we know that the oldest bacteria in the world known to us is 3.5 billion years ago. The oldest known Bacteria is called stromatolites its was found in Australia, it was found because the rocks in Australia are one of the oldest known to men so it would make sense the bacteria are there. They were surrounded by a sandstone layer in a beach. Stromatolites are fossils evidence of the prokaryotic life that remains today. Surprisingly bacteria can survive in so many different environments and conditions like in guts animals rocks food and other things that we wouldn’t believe
How did they survive so long? Some bacteria can survive impact or just live without oxygen.
Fossil Evidence for Bacteria According to fairly new information and studies bacteria are the oldest forms of life and according to some theories they have been on earth for the past 3.5 billion years. There are many evidences that support this but the real question is what factual evidence supports the theories. Two of the main evidences are the Tatahouine Evidence and the ALH84001 Evidence. These evidences both try to prove the existence of bacteria existing 3.5 billion years ago through bacteria on meteorites. Both of these evidences try to prove this theory true but both are probably not very credible because when testing these evidences the question of durability and survivability comes up. The bacteria’s survivability is not enough to prove these evidence completely true.
What fossil evidence exists for bacteria? How do scientists know bacteria existed 3.5 BYA? Include examples of the evidence they have.
ReplyDeleteScientists discovered traces of bacteria that lived 3.40 billion years ago in Australian rocks. Finding these remnants of bacteria fossils required hard look at some of the planet’s oldest rocks, located in Western Australia’s Pilbara region (Health and Science, 2013.) There are older rocks on Earth, said Maud Walsh, a biogeologist at Louisiana State University in Baton Rouge. “But these are the best-preserved sedimentary rocks we know of, the ones most likely to preserve the really tiny structures and chemicals that provide evidence for life.” (Maud Walsh, 2013)
Bacteria that can get their energy form sulphur instead of oxygen are abundant in volcanic environments today, and scientists had recently found rocks containing possible chemical evidence that sulphur-metabolizing bacteria existed almost 3.5 billion years ago. The recent discovery in the Strelley Pool rock formation demonstrates the first fossils backing up the sulphur evidence. The fossils were found in rocks that were originally formed in shallow seas near a coastline and suggest that beaches may have been the key habitat where the Earth's first lifeforms thrived, said David Wacey, of the University of Western Australia (CBC News, 2013.)
Stromatolites are not only the Earth’s oldest fossils but they are portals to the Earth’s past. Stromatolites are fossil evidence of the prokaryotic life (bacteria) that remains today. The prokaryotes are the ones who make the biosphere a habitable place for living organisms. In other words strimatolites are sedimentary fossils formed from layers of cyanobacteria, calcium carbonate, and trapped sediment (Virtual Fossil Museum, 2002-2013.)
In 1996, scientists announced the evidence of what is said to be bacterial fossils in meteorites. This evidence has been found in the 1931 Tatahouine meteorite and the Martian meteorite, found in Antarctica. Oval and rod forms have been found in the surface of the Martian meteorite, which are believed to be the bacteria fossil. After several analyses like scanning and transmission electron microscopy, NASA found magnetite crystals, which are the remnants of bacteria (MicrobeWiki, August 13, 2013.)
Sources
• CBC News, 2013
http://www.cbc.ca/news/technology/oldest-fossils-reveal-life-3-4-billion-years-ago-1.978460
• Health and Science, 2013
http://www.washingtonpost.com/national/health-science/bacterial-traces-from-35-billion-years-ago-are-oldest-fossils-experts-say/2012/12/27/9261e02c-4acb-11e2-9a42-d1ce6d0ed278_story.html
• Bacterial Fossils in Meteorites August 13, 2o13
http://microbewiki.kenyon.edu/index.php/Bacterial_Fossils_in_Meteorites
• Virtual Fossil Museum (2002-2013)
http://www.fossilmuseum.net/Tree_of_Life/Stromatolites.htm
What fossil evidence exists for bacteria? How do scientists know bacteria existed 3.5 BYA? Include examples of the evidence they have.
ReplyDeleteIt really is shocking that fossils leave bacteria. Yet, one certain group of bacteria, the cyanobacteria or "blue-green algae," have left a fossil record that spreads far back into the Precambrian - the oldest cyanobacteria-like fossils known are nearly 3.5 billion years old, among the oldest fossils currently known. Cyanobacteria are bigger than most bacteria, and may hide a thick cell wall. Cyanobacteria can form large layered structures, called stromatolites (if more or less dome-shaped) or oncolites (if round). They form as a mat of cyanobacteria grows in a water location, catching sediment and sometimes hiding calcium carbonate. When they are divided very finely, fossil stromatolites can be found to have beautifully conserved fossil cyanobacteria and algae.
The conserved cell walls of bacteria that lived in oceans without oxygen 3.4 billion years ago are thought to be the oldest fossils ever found. The tiny fossils were found in Western Australia among bands of covered rock 3.3 billion to 3.5 billion years old. The fossils were surrounded in a sandstone layer from a shallow-water beach that represents one of the Earth’s first conserved coastlines.
Scientists know that bacteria have existed since 3.5 BCY from 1996. Headings dispersed when scientists said the sign of what is demanded to be bacterial fossils in meteorites. The scientists found the bacteria with oval forms and evidence shows that it is bacteria.
Sources:
http://www.ucmp.berkeley.edu/b
http://www.cbc.ca/news/technology/oldest-fossils-reveal-life-3-4-billion-years-ago-1.978460 acteria/bacteriafr.html
http://microbewiki.kenyon.edu/index.php/Bacterial_Fossils_in_Meteorites
ReplyDeleteWhat are fossils? A fossil is the remains of a prehistoric plant or animal embedded in rock and preserved in petrified form. Fossils have been here, in this planet, around 3.5 Billions of years. I will be explaining how scientists know that fossils existed so long ago and what fossil evidence exists for bacteria.
The fossil evidence that exists from bacteria is far back into the Precambrian Era. There is one particular bacteria type that has left more fossils than any other type, it is called the cyanobacteria or "blue-green algae”. The Cyanobacteria is one of the largest bacteria there is, it also may form large layered structures called stromatolites (if more or less dome-shaped) or oncolites (if round). When fossils are very thin, fossil stromatolites may be found to contain exquisitely preserved fossil cyanobacteria and algae(1).
“In a sun-scorched region of Western Australia known as Pilbara, a team of American and Australian paleobiologists believe they have located the oldest known evidence of life on Earth. The ancient bacterial fossils have been dated as 3.49 billion years old, only about a billion years after scientists estimate the Earth was formed. According to the findings presented by the joint team at the most recent meeting of the Geological Society of America, the tiny ridges that lattice the rocks like a fishing net seem to indicate that primitive bacteria integrated themselves into expansive networks. This collective behavior, which mirrors that of modern bacteria, involved thousands of different bacteria species, each performing a unique task that contributed to the larger community”(2)
How do scientists know that fossils existed so long ago? It’s hard to tell if I should believe scientists that fossils really exist and that they really are that old, so I’m going to explain how they date fossils. First of all scientists don’t just look at it and determine what age they are. They first have to combine a series of techniques that they use to find the age of the fossil. The use Relative dating—that is when fossils are found in sedimentary rocks that formed when eroded sediments piled up in low-lying places such as river flood plains, lake bottoms or ocean floors(3). Then they use Radiometric Dating— after scientists learned that the nuclear decay of radioactive elements takes place at a predictable rate, they realized that the traces of radioactive elements present in certain types of rock, such as hardened lava and tuff (formed from compacted volcanic ash), could be analyzed chemically to determine the ages, in years, of those rocks(3). Last they put the two things together and then once it was possible to measure the ages of volcanic layers in a stack of sedimentary rock, the entire sequence could be pinned to the absolute time scale (3).
Resources:
1.Bacteria: Fossil Record
http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html
2.redOrbit; January 2, 2013
http://www.redorbit.com/news/science/1112756338/oldest-fossils-on-earth-010213/
3.How do we know the ages of fossils and fossil-bearing rocks?
http://www.mnh.si.edu/exhibits/backyard-dinosaurs/questions-answers.cfm?know=a24
Francisco
ReplyDeleteFossil evidence is that something has been found a long time ago that can proof something. Such as fossils now we know that dinosaurs existed before us and now we are sure of it we can also say how long it was. Same can be said for bacteria we know that the oldest bacteria in the world known to us is 3.5 billion years ago.
The oldest known Bacteria is called stromatolites its was found in Australia, it was found because the rocks in Australia are one of the oldest known to men so it would make sense the bacteria are there. They were surrounded by a sandstone layer in a beach. Stromatolites are fossils evidence of the prokaryotic life that remains today. Surprisingly bacteria can survive in so many different environments and conditions like in guts animals rocks food and other things that we wouldn’t believe
How did they survive so long? Some bacteria can survive impact or just live without oxygen.
Sources
http://microbewiki.kenyon.edu/index.php/Bacterial_Fossils_in_Meteorites
http://en.wikipedia.org/wiki/Stromatolite
http://www.dailymail.co.uk/sciencetech/article-2256643/The-worlds-oldest-fossils-Researchers-claim-bacteria-existed-Earth-OXYGEN.html
Fossil Evidence for Bacteria
ReplyDeleteAccording to fairly new information and studies bacteria are the oldest forms of life and according to some theories they have been on earth for the past 3.5 billion years. There are many evidences that support this but the real question is what factual evidence supports the theories.
Two of the main evidences are the Tatahouine Evidence and the ALH84001 Evidence. These evidences both try to prove the existence of bacteria existing 3.5 billion years ago through bacteria on meteorites. Both of these evidences try to prove this theory true but both are probably not very credible because when testing these evidences the question of durability and survivability comes up. The bacteria’s survivability is not enough to prove these evidence completely true.
http://microbewiki.kenyon.edu/index.php/Bacterial_Fossils_in_Meteorites