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RE: Ancient life
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Early feast clue to smell of ancient Earth

Tiny 1,900 million-year-old fossils from rocks around Lake Superior, Canada, give the first ever snapshot of organisms eating each other and suggest what the ancient Earth would have smelled like.
The fossils, preserved in Gunflint chert, capture ancient microbes in the act of feasting on a cyanobacterium-like fossil called Gunflintia - with the perforated sheaths of Gunflintia being the discarded leftovers of this early meal.

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Planet's oldest fossils found in Pilbara, experts say

Scientists analysing Australian rocks have discovered traces of bacteria that lived a record-breaking 3.49 billion years ago, a mere billion years after Earth formed. If the find withstands the scrutiny that inevitably faces claims of fossils this old, it could move scientists one step closer to understanding the first chapters of life on Earth. The discovery could also spur the search for ancient life on other planets.
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Ancient Genetic Systems
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Weber State Scientists Discover Possible Building Blocks of Ancient Genetic Systems

Scientists believe that prior to the advent of DNA as the earth's primary genetic material, early forms of life used RNA to encode genetic instructions. What sort of genetic molecules did life rely on before RNA?
The answer may be AEG, a small molecule when linked into chains form a hypothetical backbone for Peptide Nucleic Acids, which have been hypothesised as the first genetic molecules. Synthetic AEG has been studied by the pharmaceutical industry as a possible genesilencer to stop or slow certain genetic diseases. The only problem with the theory is that up to now, AEG has been unknown from nature.
A team of scientists from the USA and Sweden announced that they have discovered AEG within cyanobacteria which are believed to be some of the most primitive organisms on earth. Cyanobacteria sometimes appear as mats or scums on the surface of reservoirs and lakes during hot summer months. Their tolerance for extreme habitats is remarkable, ranging from the hot springs of Yellowstone to the tundra of the Arctic.

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RE: Ancient life
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Large bacterial population colonised land 2.75 billion years ago

There is evidence that some microbial life had migrated from the Earth's oceans to land by 2.75 billion years ago, though many scientists believe such land-based life was limited because the ozone layer that shields against ultraviolet radiation did not form until hundreds of millions years later.
But new research from the University of Washington suggests that early microbes might have been widespread on land, producing oxygen and weathering pyrite, an iron sulphide mineral, which released sulphur and molybdenum into the oceans.

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Scientists place 500-million-year-old gene in modern organism

It's a project 500 million years in the making. Only this time, instead of playing on a movie screen in Jurassic Park, it's happening in a lab at the Georgia Institute of Technology.
Using a process called paleo-experimental evolution, Georgia Tech researchers have resurrected a 500-million-year-old gene from bacteria and inserted it into modern-day Escherichia coli (E. coli) bacteria. This bacterium has now been growing for more than 1,000 generations, giving the scientists a front row seat to observe evolution in action.

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Bilaterian
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UAlberta researchers track down earliest known animal

University of Alberta researchers have uncovered physical proof that animals existed 585 million years ago - 30 million years earlier than previous records show.
The discovery was made by U of A geologists Ernesto Pecoits and Natalie Aubet in Uruguay. They found fossilised tracks a centimetre-long, slug-like animal left behind 585 million years ago in silty, shallow-water sediment.
A team of U of A researchers determined that the tracks were made by a primitive animal called a bilaterian, which is distinguished from other non-animal, simple life forms by its symmetry - its top side is distinguishable from its bottom side - and a unique set of "footprints."

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 Mankind's remotest relative is a very rare micro-organism from south-Norway.

Biologists all over the world have been eagerly awaiting the results of the genetic analysis of one of the world's smallest known species, hereafter called the protozoan, from a little lake 30 kilometre south of Oslo in Norway.
When researchers from the University of Oslo, Norway compared its genes with all other known species in the world, they saw that the protozoan did not fit on any of the main branches of the tree of life. The protozoan is not a fungus, alga, parasite, plant or animal.

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Ediacaran fossils
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Precambrian fossils, once thought to be embryos, reinterpreted as... something else

Spectacular fossils from Doushantuo in China appeared to resolve this issue. The tiny remains date from the Ediacaran, but appeared to share features with animal (more properly, metazoan) embryos, suggesting that metazoans were around for many millions of years, even though we've been unable to identify any fossils of their adult forms. Since their initial announcement, however, this interpretation has been challenged, with some even suggesting that the fossils were little more than clusters of bacteria.
Now, a group has performed X-ray imaging of the internal structure of the fossils and concluded that they most certainly aren't bacteria... but it's not actually clear what they are. The most likely identity, according to the researchers, is a relative of the first metazoans.

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Baseball-Shaped Fossils Show Early Proof of Animals

Microscopic 570-million-year-old fossils from China may represent the earliest evidence for animal life on Earth, suggests a new study in the Proceedings of the Royal Society B.
Previous theories have said that the fossils represented giant bacteria.

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Doushantuo fossils
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Doushantuo fossils are all aquatic, microscopic, and preserved to a great degree of detail. The latter two characteristics mean that the structure of the organisms that made them can be studied at the cellular level, and considerable insight has been gained into the embryonic and larval stages of many early creatures. One contentious claim is that many of the fossils show signs of bilateral symmetry, a common feature in many modern-day animals which is usually assumed to have evolved later, during the Cambrian Explosion. A nearly microscopic fossil animal, Vernanimalcula ("springtime micro-animal") was announced in October 2005, with the claim that it was the oldest known bilateral animal. However, the absence of adult forms of almost all animal types in the Doushantuo (there are microscopic adult sponges and corals) makes these claims difficult to prove: some argue that their lack suggests these finds are not larval and embryonic forms at all; supporters contend that some unidentified process "filtered out" all but the smallest forms from fossilisation.
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