Search results
Results from the WOW.Com Content Network
Estimates on the number of Earth's current species range from 10 million to 14 million, of which about 1.2 million have been documented and over 86% have not yet been described. [129] However, a May 2016 scientific report estimates that 1 trillion species are currently on Earth, with only one-thousandth of one percent described. [ 130 ]
Insects make up the vast majority of animal species. [14]Chapman, 2005 and 2009 [9] has attempted to compile perhaps the most comprehensive recent statistics on numbers of extant species, drawing on a range of published and unpublished sources, and has come up with a figure of approximately 1.9 million estimated described taxa, as against possibly a total of between 11 and 12 million ...
By the time Pangaea broke up, in the Middle Jurassic, the seas swarmed with molluscs (particularly ammonites), [41] ichthyosaurs, sharks and rays, and the first ray-finned bony fishes, while life on land was dominated by forests of cycads and conifers in which dinosaurs flourished and in which the first true mammals had appeared. [42] [43]
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.
In the absence of a magnetic field, charged particles from the Sun will deplete the atmosphere and further increase the Earth's temperature to an average of around 420 K (147 °C, 296 °F) in 2.8 billion years, causing the last remaining life on Earth to die out. This is the most extreme instance of a climate-caused extinction event.
The biosphere (from Ancient Greek βίος (bíos) 'life' and σφαῖρα (sphaîra) 'sphere'), also called the ecosphere (from Ancient Greek οἶκος (oîkos) 'settlement, house' and σφαῖρα (sphaîra) 'sphere'), is the worldwide sum of all ecosystems. It can also be termed the zone of life on the Earth.
The time value of money means that money is worth more now than in the future because of its potential growth and earning power over time. In other words, receiving a dollar today is more valuable ...
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 ...