12/29/2023 0 Comments Fman appears on earthīacteria develop primitive photosynthesis, which at first did not produce oxygen. Last universal common ancestor (LUCA): split between bacteria and archaea. The earliest evidence for life on Earth includes: 3.8 billion-year-old biogenic hematite in a banded iron formation of the Nuvvuagittuq Greenstone Belt in Canada graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia. These first organisms are believed to have been chemoautotrophs, using carbon dioxide as a carbon source and oxidizing inorganic materials to extract energy.įormation of a greenstone belt of the Isua complex in western Greenland, whose isotope frequencies suggest the presence of life. Probable origin of life.įormation of a greenstone belt of the Acasta Gneiss of the Slave craton in northwest Canada - the oldest known rock belt. Possible remains of biotic life were found in 4.1 billion-year-old rocks in Western Australia. Thermal flux from widespread hydrothermal activity during the LHB may have aided abiogenesis and life's early diversification. Late Heavy Bombardment (LHB): extended barrage by meteoroids impacting the inner planets. įactors in mass extinctions include continental drift, changes in atmospheric and marine chemistry, volcanism and other aspects of mountain formation, changes in glaciation, changes in sea level, and impact events. The Holocene extinction event is currently under way. Smaller extinction events have occurred in the periods between, with some dividing geologic time periods and epochs.
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