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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 ...
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. [32] [33 ...
Earth is the only place in the universe known to harbor life, where it exists in myriad environments. [8] [9] The origin of life on Earth was at least 3.5 billion years ago, possibly as early as 3.8-4.1 billion years ago. [2] [3] [4] Since its emergence, life has persisted in
Life: A Natural History of the First Four Billion Years of Life on Earth is a book about natural history by British paleontologist Richard A. Fortey. It was originally published in hardcover in Great Britain by HarperCollins Publishers, under the title Life: An Unauthorised Biography. Fortey used this book to explain how life has evolved over ...
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.
Earth is the third planet from the Sun and the only astronomical object known to harbor life. [23] This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all of Earth's water is contained in its global ocean, covering 70.8% of Earth's crust.
It can also be termed as the zone of life on Earth, a closed system (apart from solar and cosmic radiation and heat from the interior of the Earth), and largely self-regulating. [100] Organisms exist in every part of the biosphere, including soil , hot springs , inside rocks at least 19 km (12 mi) deep underground, the deepest parts of the ...
The Boring Billion, otherwise known as the Mid Proterozoic and Earth's Middle Ages, is an informal geological time period between 1.8 and 0.8 billion years ago during the middle Proterozoic eon spanning from the Statherian to the Tonian periods, characterized by more or less tectonic stability, climatic stasis and slow biological evolution.