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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 first known mass extinction was the Great Oxidation Event 2.4 billion years ago, which killed most of the planet's obligate anaerobes. Researchers have identified five other major extinction events in Earth's history, with estimated losses below: [11] End Ordovician: 440 million years ago, 86% of all species lost, including graptolites
Evidence of possibly the oldest forms of life on Earth has been found in hydrothermal vent precipitates. [1]The earliest known life forms on Earth may be as old as 4.1 billion years (or Ga) according to biologically fractionated graphite inside a single zircon grain in the Jack Hills range of Australia. [2]
An early, inefficient version of diaphragm may have evolved in synapsids. The earliest synapsids, or "proto-mammals," are the pelycosaurs. The pelycosaurs were the first animals to have temporal fenestrae. Pelycosaurs were not therapsids but their ancestors. The therapsids were, in turn, the ancestors of mammals.
The Earth was formed at 4.54 Gya, and the earliest evidence of life on Earth dates from at least 3.8 Gya from Western Australia. Some studies have suggested that fossil micro-organisms may have lived within hydrothermal vent precipitates dated 3.77 to 4.28 Gya from Quebec, soon after ocean formation 4.4 Gya during the Hadean.
All life on Earth can be traced back to a Last Universal Common Ancestor, or LUCA. A new study suggests that this organism likely lived on Earth only 400 million years after its formation.
A new study suggests that cloud-to-ground lightning likely provided the necessary material for the first organisms on Earth to form. ... of early Earth life forms, and provide a template for how ...
This evidence, along with Barberton fossils, show that cellular life must have existed by this point in the evolution of Earth. There is work that potentially demonstrates life at 3.8 billion years ago, in what is now western Greenland, [4] [5] but it is highly debated. Cellular life existed 3.5 billion years ago and thus it evolved prior to ...