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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; [30] graphite in 3.7 billion-year-old metasedimentary rocks in western Greenland; [31] and microbial mat fossils in 3.48 billion-year-old sandstone in Western Australia.
The history of life on Earth traces the processes by which living and extinct organisms evolved, from the earliest emergence of life to the present day. Earth formed about 4.5 billion years ago (abbreviated as Ga, for gigaannum) and evidence suggests that life emerged prior to 3.7 Ga. [1] [2] [3] The similarities among all known present-day species indicate that they have diverged through the ...
A. afarensis also has a relatively small brain size (380–430 cm 3) and a prognathic (anterior-projecting) face. Australopithecines have been found in savannah environments; they probably developed their diet to include scavenged meat.
A new study says complex life began 1.5 billion years earlier, influenced by ancient volcanic activity, reshaping our understanding of life's timeline on Earth.
Parts of the world now have sub-replacement fertility rates. [544] Public health measures and advances in medical science contributed to a sharp increase in global life expectancy at birth from about 31 years in 1900 to over 66 years in 2000. [545] [y] In 1820, 75% of humanity lived on less than one dollar a day, while in 2001 only about 20% ...
The theory of panspermia speculates that life on Earth may have come from biological matter carried by space dust [93] or meteorites. [94] While current geochemical evidence dates the origin of life to possibly as early as 4.1 Ga, and fossil evidence shows life at 3.5 Ga, some researchers speculate that life may have started nearly 4.5 billion ...
The Bennu organic compounds all have been identified previously in meteorites that have landed on Earth. But there have been lingering questions because these meteorites could have been ...
The first eon in Earth's history, the Hadean, begins with Earth's formation and is followed by the Archean eon at 3.8 Ga. [2]: 145 The oldest rocks found on Earth date to about 4.0 Ga, and the oldest detrital zircon crystals in rocks to about 4.4 Ga, [34] [35] [36] soon after the formation of Earth's crust and Earth itself.