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Nevertheless, it is believed that primordial life began to evolve by the early Archean, with candidate fossils dated to around 3.5 Ga. [42] Some scientists even speculate that life could have begun during the early Hadean, as far back as 4.4 Ga, surviving the possible Late Heavy Bombardment period in hydrothermal vents below the Earth's surface.
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 ...
The age of Earth is about 4.54 billion years; [7] [33] [34] the earliest undisputed evidence of life on Earth dates from at least 3.5 billion years ago according to the stromatolite record. [35] Some computer models suggest life began as early as 4.5 billion years ago. [36] [37] The oldest evidence of life is indirect in the form of isotopic ...
c. 315 Ma – The evolution of the first reptiles. c. 312 Ma – Hylonomus makes first appearance, one of the oldest reptiles found in the fossil record. c. 306 Ma – Diplocaulus evolves in the swamps with an unusual boomerang-like skull. c. 305 Ma – First diapsids evolve; Meganeura, a giant dragonfly dominates the skies.
It is widely believed that the early Earth was dominated by vertical tectonic processes, such as stagnant lid, [19] [20] heat-pipe, [21] or sagduction, [22] [23] [24] which eventually transitioned to plate tectonics during the planet's mid-stage evolution. However, an alternative view proposes that Earth never experienced a vertical tectonic ...
From climate change to species loss and pollution, humans have etched their impact on the Earth with such strength and permanence since the middle of the 20th century that a special team of ...
All life on Earth—including humanity—shares a last universal common ancestor (LUCA), [9] [10] [11] which lived approximately 3.5–3.8 billion years ago. [12] The fossil record includes a progression from early biogenic graphite [13] to microbial mat fossils [14] [15] [16] to fossilised multicellular organisms.