The notion of limiting historical study to a roughly 5000-year span, out of a possible few million years of human existence, and of only those few world cultures that left written records, is hardly tenable. It remains a possibility that somewhere between the origins of intelligent humanoids and first preserved artifact, or indeed in the vast periods on the geologic time scale, long before what we call ancient history, there existed sophisticated civilizations on Earth that matched or even surpassed our current one.
Namýšľali sme si, že sme veční. A pritom tu ostanú tu len mravce a lišajníky. A ryby. Potom, za pár miliónov rokov vylezie z mora nejaký dôstojnejší nasledovník človeka. Nová rasa, možno nejaké chodiace delfíny. A celkom isto tu, na tomto mieste, bude jedného dňa namiesto mňa sedieť mladá delfínka a bude práve raňajkovať toasty, keď jej ktosi telepaticky oznámi tú novinu. A zasa prídu noví nájomníci. Nesmierny cyklus civilizácií za hranicami nášho chápania...Ráno večnosti, ()
Prehistoric civilizations— The notion of limiting historical study to a roughly 5000-year span, out of a possible few million years of human existence, and of only those few world cultures that left written records, is hardly tenable. It remains a possibility that somewhere between the origins of intelligent humanoids and first preserved artifact, or indeed in the vast periods on the geologic time scale, long before what we call ancient history, there existed sophisticated civilizations on Earth that matched or even surpassed our current one.
Ancient cave women 'left childhood homes'— Analysis of early human-like populations in southern Africa suggests females left their childhood homes, while males stayed at home. An international team examined tooth samples for metallic traces which can be linked to the geological areas in which individuals grew up. The conclusion was that while most the males lived and died around the same river valley, the females moved on. Similar patterns have been observed in chimpanzees, bonobos and modern humans.(1. July 2011)
Ancient life thrives in the deep— There is evidence that life evolved in the deep sediments. ... There is clear evidence that life existed more than 3.8 billion years ago. Although, for there to be a big enough biomass for us to detect it in the rocks, it must have been evolving long before that. ... The normal view of life on Earth is that the majority of life is on the surface, fuelled by sunlight. And you don't expect a large population - even bacteria - to survive away from that source. But we are finding that there are a lot of geological sources of energy below the surface. For example, there are a lot of processes that produce hydrogen, which is a good source of energy for bacteria. ... It reinforces the idea that this large bacterial biosphere is in fact living rather than fossil bacteria. Some of the cells are imbedded in sediments that are many millions of years old, which means they must be ancient, too. These bacteria are growing very slowly in the subsurface. They could effectively be immortal.(23. February 2005)
And life created continents...— Life on Earth may have driven the evolution of the planet itself. The idea is that ancient microbes provided the chemical energy to create the Earth's continents - a nod to the Gaia hypothesis, in which life helps create the conditions it needs to survive. The theory would solve the puzzle of why the Earth's continental crust appeared when it did, and explain the presence of granite, a substance not found anywhere else in our solar system.(24. March 2006)
Is this the meaning of life?— However, recent advances in our understanding of evolution are revealing a bigger picture that can, by itself, give meaning to life. This new worldview locates humanity within a much larger evolutionary process that appears to offer us a meaningful role to play. This new understanding of evolution is founded on the recognition that evolution is headed somewhere – it has a trajectory. In particular, evolution on Earth has repeatedly gathered small-scale entities into cooperative organisations on a progressively larger and larger scale. Self-replicating molecular processes were organised into the first simple cells. Communities of these simple, prokaryotic cells formed the more complex eukaryotic cell. Collections of these formed multicellular organisms, and organisms were organised into cooperative societies.(5. March 2010)
Team finds Earth's 'oldest rocks'— Earth's most ancient rocks, with an age of 4.28 billion years, have been found on the shore of Hudson Bay, Canada.(26. September 2008)
The Drake Equation and the search for new lifeforms— In 1960, Dr Frank Drake came up with the Drake Equation - a formula calculating the likelihood of of extraterrestrial intelligence from seven key elements. The figures, approximate as they were, suggested the number of alien civilisations able to communicate with Earth was at least 10,000. But with the recent discovery of microbes which thrive in an arsenic-rich environment, scientists are now contending with the idea that life on Earth arose not once, but twice. Such a discovery would have profound implications for the Drake Equation and the search for alien life.(15. December 2010)
Water 'widespread' on early Mars— Water was once widespread on Mars, data from a Nasa spacecraft shows, raising the prospect that the Red Planet could have supported life. ... Rocks of this age have largely been destroyed on Earth by plate tectonics. They are preserved on the Moon, but were never exposed to liquid water. So rocks containing phyllosilicates on Mars preserve a unique record of watery environments in the early Solar System, some of which could have been stable long enough for life to get started.(17. July 2008)