This is a collection of lists of organisms by their population. While most of the numbers are estimates, they have been made by the experts in their fields. Species population is a science falling under the purview of population ecology and biogeography. Individuals are counted by census, as carried out for the piping plover;[3][4] using the transect method, as done for the mountain plover;[5] and beginning in 2012 by satellite, with the emperor penguin being first subject counted in this manner.[6]
Number of species
More than 99 percent of all species, amounting to over five billion species,[7] that ever lived on Earth are estimated to be extinct.[8][9] Estimates on the number of Earth's current species range from 10 million to 14 million,[10] of which about 1.2 million have been documented and over 86 percent have not yet been described.[11] According to another study, the number of described species has been estimated at 1,899,587.[12] 2000–2009 saw approximately 17,000 species described per year.[12] The total number of undescribed organisms is unknown, but marine microbial species alone could number 20,000,000.[12] For this reason, the number of quantified species will always lag behind the number of described species, and species contained in these lists tend to be on the K side of the r/K selection continuum. More recently, in May 2016, scientists reported that 1 trillion species are estimated to be on Earth currently with only one-thousandth of one percent described.[13] The total number of related DNA base pairs on Earth is estimated at 5.0 x 1037 and weighs 50 billion tonnes.[14] In comparison, the total mass of the biosphere has been estimated to be as much as 4 TtC (trillion [million million] tonnes of carbon).[15] In July 2016, scientists reported identifying a set of 355 genes from the Last universal common ancestor (LUCA) of all organisms living on Earth.[16]
By domain
The domain of eukaryotes represent a small minority of the number of organisms;[17] however, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes.[17] Prokaryotes number about 4–6 × 1030 cells and 350–550 Pg of C.[18]
Microbes
It is estimated that the most numerous bacteria are of a species of the Pelagibacterales (or SAR11) clade, perhaps Pelagibacter ubique, and the most numerous viruses are bacteriophages infecting these species.[19] It is estimated that the oceans contain about 2.4 × 1028 (24 octillion) SAR11 cells.[20]The Deep Carbon Observatory has been exploring living forms in the interior of the Earth. "Life in deep Earth totals 15 to 23 billion tons of carbon".[21]
The domesticated chicken (Gallus gallus domesticus), a Galliform, has an estimated population of 23.7 billion,[22] which is higher than any other bird.[23]
Recent figures indicate that there are more than 1.4 billion insects for each human on the planet,[27] or roughly 1019 (10 quintillion) individual living insects on the earth at any given time.[28] An article in The New York Times claimed that the world holds 300 pounds of insects for every pound of humans.[28] Ants have colonised almost every landmass on Earth. Their population is estimated as between 1016–1017 (10-100 quadrillion).[29] With an estimated 20 quadrillion ants their biomass comes to 12 megatons of dry carbon, which is more than all wild birds and non-human mammals combined.[30][31][32]
Plantae
Trees
According to NASA in 2005, there were over 400 billion trees on our globe.[33] However, more recently, in 2015, using better methods, the global tree count has been estimated at 3 trillion.[34] Other studies show that the Amazonian forest alone yields approximately 430 billion trees.[35] Extrapolations from data compiled over a period of 10 years suggest that greater Amazonia, which includes the Amazon Basin and the Guiana Shield, harbors around 390 billion individual trees.[36]
^Forest and Rangeland Ecosystem Science Center. "2011 International Piping Plover Census: Study Description". United States Geological Survey. Retrieved 2012-12-24.
^"Positive Piping Plover Count". Government of Saskatchewan. 6 Nov 2006. Archived from the original on 2013-05-06. Retrieved 2012-12-24.
^"Mountain plover survey guidelines — Wyoming" (PDF). United States Fish and Wildlife Service. March 2002. Archived from the original (PDF) on 2013-06-02. Retrieved 2012-12-24.
^Dell'Amore, Christine (13 April 2012). "Emperor Penguins Counted From Space—A First". National Geographic News. National Geographic. Archived from the original on April 15, 2012. Retrieved 2012-12-22.
^Kunin, W.E.; Gaston, Kevin, eds. (31 December 1996). The Biology of Rarity: Causes and consequences of rare—common differences. Springer. ISBN 978-0412633805. Retrieved 26 May 2015.
^Stearns, Beverly Peterson; Stearns, S. C.; Stearns, Stephen C. (2000). Watching, from the Edge of Extinction. Yale University Press. p. preface x. ISBN 978-0-300-08469-6. Retrieved 30 May 2017.
^Novacek, Michael J. (8 November 2014). "Prehistory's Brilliant Future". New York Times. Retrieved 2014-12-25.
^G. Miller; Scott Spoolman (2012). Environmental Science - Biodiversity Is a Crucial Part of the Earth's Natural Capital. Cengage Learning. p. 62. ISBN 978-1-133-70787-5. Retrieved 2014-12-27.
^Mora, C.; Tittensor, D.P.; Adl, S.; Simpson, A.G.; Worm, B. (23 August 2011). "How many species are there on Earth and in the ocean?". PLOS Biology. 9 (8): e1001127. doi:10.1371/journal.pbio.1001127. PMC 3160336. PMID 21886479.
^ a b cPennak, Sara; et al. (18 January 2012). "State of observed species: A decade of species discovery in review" (PDF). International Institute for Species Exploration; Arizona State University. Archived from the original (PDF) on 31 October 2012. Retrieved 2013-01-02.
^Staff (2 May 2016). "Researchers find that Earth may be home to 1 trillion species". National Science Foundation. Retrieved 6 May 2016.
^Nuwer, Rachel (18 July 2015). "Counting All the DNA on Earth". The New York Times. New York. ISSN 0362-4331. Retrieved 2015-07-18.
^"The Biosphere: Diversity of Life". Aspen Global Change Institute. Basalt, CO. Archived from the original on 2014-11-10. Retrieved 2015-07-19.
^Wade, Nicholas (25 July 2016). "Meet Luca, the Ancestor of All Living Things". New York Times. Retrieved 25 July 2016.
^ a bWhitman WB, Coleman DC, Wiebe WJ (June 1998). "Prokaryotes: the unseen majority" (PDF). Proceedings of the National Academy of Sciences of the United States of America. 95 (12): 6578–6583. Bibcode:1998PNAS...95.6578W. doi:10.1073/pnas.95.12.6578. PMC 33863. PMID 9618454. Archived (PDF) from the original on 20 August 2008. Retrieved 16 September 2011.
^Whitman, William B.; Coleman, David C.; Wiebe, William J. (1998-06-09). "Prokaryotes: The unseen majority". Proceedings of the National Academy of Sciences. 95 (12): 6578–6583. Bibcode:1998PNAS...95.6578W. doi:10.1073/pnas.95.12.6578. ISSN 0027-8424. PMC 33863. PMID 9618454.
^Erin M. Eggleston; Ian Hewson (2016). "Abundance of Two Pelagibacter ubique Bacteriophage Genotypes along a Latitudinal Transect in the North and South Atlantic Oceans". Frontiers in Microbiology. 7: 1534. doi:10.3389/fmicb.2016.01534. PMC 5039313. PMID 27733846.
^Merry Youle & Gemma Reguera (February 22, 2015). "The Most Abundant Small Things Considered".
^"Life in deep Earth totals 15 to 23 billion tons of carbon—hundreds of times more than humans". phys.org. Retrieved 2018-12-30.
^"Number of chickens worldwide from 1990 to 2018". Statista. Retrieved 23 February 2020.
^UN's Food and Agriculture Organisation (July 2011). "Global Livestock Counts". The Economist. Archived from the original on July 15, 2016. Retrieved July 13, 2017.
^Alligators, River Dolphins, Giant Salamanders In China - China | Facts And Details Archived 2010-11-23 at the Wayback Machine
^Trooper Walsh; Murphy, James Jerome; Claudio Ciofi; Colomba De LA Panouse (2002). Komodo Dragons: Biology and Conservation (Zoo and Aquarium Biology and Conservation Series). Washington, D.C.: Smithsonian Books. ISBN 1-58834-073-2.
^"Ora (Komodo Island Monitor or Komodo Dragon)". American Museum of Natural History. Archived from the original on March 7, 2010. Retrieved 2007-01-15.{{cite web}}: CS1 maint: unfit URL (link)
^Worrall, Simon (6 August 2017). "Without Bugs, We Might All Be Dead". National Geographic Society. Archived from the original on August 6, 2017. Retrieved 27 May 2018.
^ a b""Numbers of Insects - Species and individuals"". Smithsonian Institution. Retrieved 23 Nov 2022.
^Embery, Joan and Lucaire, Ed (1983) Collection of Amazing Animal Facts.
^"How many ants are on Earth? 20 quadrillion, study says". France 24. September 19, 2022. Retrieved September 19, 2022.
^Grandoni, Dino (September 19, 2022). "How many ants are crawling the Earth? Nearly 20 quadrillion, scientists say". Washington Post. Retrieved September 19, 2022.
^Schultheiss P, Nooten SS, Wang R, Wong MKL, Brassard F, Guénard B (2022). "The abundance, biomass, and distribution of ants on Earth". Proc Natl Acad Sci U S A. 119 (40): e2201550119. Bibcode:2022PNAS..11901550S. doi:10.1073/pnas.2201550119. PMC 9546634. PMID 36122199.{{cite journal}}: CS1 maint: multiple names: authors list (link)
^"Going Out On A Limb With A Tree-Person Ratio : Krulwich Wonders... : NPR".[permanent dead link]
^Ehrenberg, Rachel (2 September 2015). "Global count reaches 3 trillion trees - Approach combines ground-based surveys with satellite imaging to find higher density than anticipated". Nature. doi:10.1038/nature.2015.18287. S2CID 189415504. Retrieved 28 November 2015.
^"How many tree species are there in the Amazon and how many of them will go extinct?". Archived from the original on 26 March 2012.
^"Field Museum scientists estimate 16,000 tree species in the Amazon". EurekAlert!.
This article includes a species-related list of lists.