By Laura Shin
Posting in Environment
Scientists have found the oldest fossils yet, providing evidence that life existed 3.4 billion years ago in an oxygen-free environment.
Scientists have found the oldest fossils yet, providing evidence that life existed 3.4 billion years ago in an oxygen-free environment. The fossils are of bacterial cells that appear to have subsisted on sulfur. The researchers' work has implications for looking for life on other planets, giving an indication of what bacteria and cells in other oxygen-free environments might look like.
At the time of these fossils' origin, volcanoes dominated the Earth, land was constrained mostly to small islands poking up through the hot seas and circulating currents were much stronger than today. The planet was the temperature of a hot bath, and the sauna-like atmosphere was heightened by an overcast sky that retained the Earth's heat although the sun was weaker than it is today.
There were no plants or algae to photosynthesize and produce oxygen, so the bacteria existing at this time lived off of sulfur-containing compounds. Today, such sulfur-metabolizing bacteria are found in hydrothermal vents, hot springs and other places that have little free oxygen.
“This ability to essentially ‘breathe’ sulfur compounds has long been thought to be one of the earliest stages in the transition from a non-biological to biological world,” David Wacey, a postdoctoral researcher at the University of Western Australia who led the study, told Popular Science.
Until now, Archaean rocks, the earliest-known ones from the Precambrian era, have shown evidence for sulfur-based life forms, but it has been difficult to find fossils of such organisms and even harder to verify that they were actually living.
The researchers from UWA and the University of Oxford say that their fossils satisfy three crucial tests indicating that the fossils show evidence of biological forms and are not the product of a mineralization process:
- They show precise cell-like structure all of a similar size and look like microfossils from two billion years ago.
- The fossils show biological behavior because they are clustered in groups, only present in appropriate habitats and are attached to sand grains.
- And most crucially, they show biological metabolisms. They have the right chemical makeup, and the pyrite (fool's gold) found with the microfossils are likely byproducts of sulfur metabolism.
The fossils were found in the Strelley Pool Formation (seen at left), an outcropping of rocks in Western Australia that represents the oldest beach on earth.
The researchers, who reported their finding in Nature Geoscience, acknowledge it is difficult to prove whether fossils from the Archaean era were once biological organisms, but they used three methods of analysis to show that the fossils do contain carbon-based material (as opposed containing carbon that resulted from later contamination).
The three techniques they used were Raman spectroscopy, high-resolution transmission electron microscopy and geochemical analysis.
The same Oxford team had previously studied ancient fossils from a site just 20 miles away and did not deem them to be of biological origin.
Implications for life on other planets
This finding could indicate what life on other planets might look like. It would likely be similar kinds of bacteria and cells living in similar environments that would need to pass the same tests.
In the press release, researcher Martin Brasier of Oxford University, says:
Could these sorts of things exist on Mars? It's just about conceivable But it would need these approaches -- mapping the chemistry of any microfossils in fine detail and convincing three-dimensional images -- to support any evidence for life on Mars.
photos: David Wacey
Aug 21, 2011
It is absolutely inconceivable by any imagination or scientific stretch that the mega-universe and any complex life forms on earth or elsewhere just "happened". Given the extensive and exhaustive empirical studies done along with still unsolved "mysteries" that currently exist on our planet, we are still groping in the dark and "umbilically" connected to a planet we cannot escape due to the unfathomable constraints. This includes our limited intellect and physical capability..... A Fairy Tale died for our sins?? Or is this historically proven fact a fallacy or slight of hand trickery? God knows we are easily entertained and dysfunctionally disoriented by gimmickry and illusion.... by the way, according to the story.... what was in that handful of dirt in the beginning? As the story goes.... we were the last to be created... and not very long ago in comparison.
Find a fossil, so let's build a whole culture around it. To quote from the New American Encyclopedia: "Index fossils are useful in identifying and dating rock strata." "The age of fossils - including index fossils - is usually determined from the age of the rock in which it is found." So the rock strata is dated by the index fossils contained therein, and then the age of index fossils is determined by the age of the rock strata in which it is found. How convenient. As far as the Strelley Pool Formation goes, "Palaeontologists and geologists conclude that this area was once submerged under the ocean and formed a fairly flat area, perhaps the floor of a shallow ocean. As this now-arid region was once underwater, stromatolite-forming microbes would have thrived in a shallow sea where the water kept them moist but the Sun???s rays could still penetrate and fuel photosynthesis." Fossils are most common in sedimentary rock formations - river beds, ocean floors, flood zones, watering holes - places that were underwater at some time. Many of those underwater places are now on dry land, such as the Strelley Pool.
Imagine that within the gas giant planets there are forms of life floating around. Deep inside it is warm enough. The pressures and gravitational fields are strong yet relatively uniform. The basic chemical building blocks are all there. There has been more than adequate time for these life forms to develop. Finally the volume of space for development is tremendous inside Jupiter and Saturn especially. I posit that there may indeed be other forms of intelligent life right here in our own solar system, inaccessible and isolated, whom do not even know of the existence of our universe, only the environment they are constrained to. They may be highly advanced in many ways and not even know there is more to their existence than their own environment. And hence it may be the same for us, everything we think we see may not really be all there really is. We are constrained by our senses. Read A Critique of Pure Reason by Kant.
Is infinitely greater than of there not being any other than us. The probability of extra-terrestrials visiting this planet is extremely high given the extensive history of our ancesters carvings and writings and the shear quantity of recent sightings. Even if they are only circumstantial the shear volume of these encounters is overwheming.
..yes..we all started from gases..and microbes penetrating the earth via comets and meteoric bombardment..amazing what has evolved here..and what we may find..or what is developing elsewhere in our universe! Prove that statement!
Given the same testing environment, the synthetic soles of my boots would show signs of life; i.e., the fossil fuel (oil) that plastics are derived from were, at some point, living creatures and/or plants bearing traces of that life. How can intelligent people concern themselves with "3.4 billion years ago" when they still don't know why every calendar known to exist is based on a seven(7) day week?
The researchers in the article seemed to have found an ancient form of microbial life that lived in a different enviroment than we have now. This makes a case for life forms being able to exist in different environments than what we find on earth. There are also extremophiles, life that lives in extreme environments ranging from volcanic vents to super acidic waters. This shows that life can exist beyond the "Goldilocks" realm of not too hot and not too cold.
Even when a man walks into a crowded street and kills someone in the sight of a host of bystanders, the media are careful to speak of "the alleged gunman." Shouldn't Laura Shin have written "Sulfur formations alleged to be the oldest fossils found"? I mean, there is more than a shadow of a doubt here....
There saying we are made from star dust,look in time were walking,and talking but the other planets are not made from the big Bang?And there not walking and talking before Man?What a bunch of ass holes!
Not every calendar is based on 7 day week. In the past there have been different calendars with differing weeks. The best explaination about why the western calendar has 7 days per week is that the quarters of the moon are about 7 days long, 4 quarters give us a month.
If someone has found older fossils, they would have reported it to the international scientific community. It's not the sort of thing that's kept secret.
Intelligent input is good..let's clean up the language..and keep it on the 'upper' level..thank you!....yes..we all started from gases..and microbes penetrating the earth via comets and meteoric bombardment..amazing what has evolved here..and what we may find..or what is developing elsewhere in our universe!