* Astronomy

Blobrana · L

RE: Ancient life

Blobrana · L

Once upon a time, our atmosphere was a little thin on oxygen. Like, there wasnt any. Then, about three billion years ago, a handful of bacteria figured out how to harvest the energy from sunlight to make themselves some food. In the process, they consumed carbon dioxide, and gave off oxygen. So the air filled with oxygen, and all was right with the world. If youve ever taken an intro biology course, youve no doubt heard the tale. Photosynthetic bacteria are the heroes who brought oxygen to our planet.
But maybe theres more to the story than that. Because in the online issue of Nature Geoscience, researchers from Australia say: the bacteria didnt act alone. The scientists looked at atmospheric oxygen levels throughout Earths history. And they found that the amount of oxygen in the air spiked each time smaller land masses collided to form a supercontinent, like Pangea. These massive pile-ups generated mountain chains, and as the mountains eroded, they released nutrients into the oceans, feeding the photosynthetic bacteria.

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Blobrana · L

Yale University researchers believe that the earliest forms of life on Earth were single strands of nucleotides, which performed some of the complicated cellular functions proteins are known to carry out at present.
They say that their surmise is based on the finding that bacterial cells use ancient forms of RNA to swim, morph into new forms, and even become dangerously virulent all without initial involvement of DNA.

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Blobrana · L

Tiny slivers of diamond forged on an infant Earth may contain the earliest traces of life, a study has shown.
Analysis of the crystals showed they contain a form of carbon often associated with plants and bacteria.
The rare gems were found inside zircon crystals, formed a few hundred million years after the Earth came into being.

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Blobrana · L

Stromatolites

Blobrana · L

RE: Ancient life

Blobrana · L

Before dinosaurs ruled, the world belonged to giant ****roaches, dragonflies with 2-foot wingspans and millipede-type creatures the size of an average man.
These early life forms and other primitive fish, reptiles and plants are the focus of a new permanent Palaeozoic gallery opening today at the Sam Noble Oklahoma Museum of Natural History, 2401 Chautauqua Ave. on the University of Oklahoma's Norman campus.

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Blobrana · L

Life on Earth may have begun much earlier than the accepted date of about 3.5 billion years ago, according to a study of bacteria colonies near Australia's western tip.
Colonies of bacteria in tidal pools at Shark Bay grow rock-like structures, known as stromatolites, that are comparable with ancient stromatolite fossils found in the nearby Pilbara region of WA, researchers from the University of NSW's Australian Centre for Astrobiology (ACA) say.

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Blobrana · L

The lost civilisation of Atlantis may just be legend, but way down below the ocean (to quote the folksinger Donovan) there are some things that are very real namely, bacteria and archaea. By some estimates, sub-seafloor prokaryotes may account for two-thirds of the biomass of these types of organisms on Earth.
The latest evidence for such a huge undersea biosphere, and a depth record of sorts, is reported in Science by R. John Parkes of Cardiff University and colleagues. They have found living prokaryotes 5,335 feet below the ocean floor off Newfoundland, about twice as deep as the previous record.

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Blobrana · L

A long, thin rope-like creature standing erect on the sea floor up to 570 million years ago has been identified as the first animal on Earth to have had sex.
Fossilised remains of the mysterious tubular creature have been uncovered in Australia and put back the history of sex by up to 30 million years. While the experience was unlikely to have been memorable for the animals, the discovery has excited scientists who said that the fossils open a window on one of the most ancient ecosystems.
The knobbly animal, named Funisia dorothea, is thought most likely to have reproduced in a similar way to modern corals and sponges, but little else is understood of its biology.

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Two paleontologists studying ancient fossils they excavated in the South Australian outback argue that Earths ecosystem has been complex for hundreds of millions of years at least since around 565 million years ago, which is included in a period in Earths history called the Neoproterozoic era.

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