Editing Bonobo (section)

== Taxonomy ==
The bonobo was first recognised as a distinct [[taxon]] in 1928 by German anatomist [[Ernst Schwarz (zoologist)|Ernst Schwarz]], based on a skull in the [[Royal Museum for Central Africa|Tervuren Museum]] in Belgium which had previously been classified as a juvenile [[chimpanzee]] (''Pan troglodytes''). Schwarz published his findings in 1929, classifying the bonobo as a subspecies of chimpanzee, ''Pan satyrus paniscus''.<ref name="Schwarz1929">{{cite journal |vauthors=Schwarz E |date=April 1, 1929 |title=Das Vorkommen des Schimpansen auf den linken Kongo-Ufer |journal=Revue de Zoologie et de Botanique Africaines |volume=16 |pages=425–426 |url=http://www.metafro.be/primates/English_translation_of_Schwarz.pdf |access-date=April 4, 2015 |archive-date=July 19, 2021 |archive-url=https://web.archive.org/web/20210719053540/http://www.metafro.be/primates/English_translation_of_Schwarz.pdf |url-status=dead }}</ref><ref name="Coolidge1933">{{cite journal | vauthors = Coolidge Jr HJ |date=July–September 1933 |title=''Pan paniscus''. Pigmy chimpanzee from south of the Congo river |journal=American Journal of Physical Anthropology |volume=18 |issue=1 |pages=1–59 |doi=10.1002/ajpa.1330180113}} Coolidge's paper contains a translation of Schwarz's earlier report.</ref> In 1933, American anatomist [[Harold Jefferson Coolidge, Jr.|Harold Coolidge]] elevated it to species status.<ref name="Coolidge1933" /><ref name="Herzfeld2007">{{cite journal |vauthors=Herzfeld C |year=2007 |title=L'invention du bonobo |language=fr |journal=Bulletin d'Histoire et d'Épistémologie des Sciences de la Vie |volume=14 |issue=2 |pages=139–162 |url=http://www.chrisherzfeld.com/userfiles/publications/BONOBO.pdf |access-date=21 December 2011 |doi=10.3917/bhesv.142.0139 |archive-date=12 December 2022 |archive-url=https://web.archive.org/web/20221212181134/http://www.chrisherzfeld.com/userfiles/publications/BONOBO.pdf |url-status=live }}</ref> Major behavioural differences between bonobos and chimpanzees were first discussed in detail by Tratz and Heck in the early 1950s.<ref name="deWaal2002">{{cite book | vauthors = de Waal FB |year=2002 |title=Tree of Origin: What Primate Behavior Can Tell Us About Human Social Evolution |isbn=978-0-674-01004-8 |publisher=Harvard University Press |page=51}}</ref> Unaware of any taxonomic distinction with the common chimpanzee, American psychologist and primatologist [[Robert Yerkes]] had already noticed an unexpected major behavioural difference in the 1920s.<ref>{{cite book |title=Our Inner Ape |first=Frans |last=de Waal |authorlink=Frans de Waal |page=30 |publisher=Penguin |year=2006 |isbn=978-1-59448-196-3 |url=https://books.google.com/books?id=lDP4TPccgC8C&dq=%22Robert+Yerkes%22+%22expressed+doubt+that+Prince+Chim+was+a+regular+chimp%22%22&pg=PA30 |access-date=2023-04-23 |archive-date=2023-07-30 |archive-url=https://web.archive.org/web/20230730121832/https://books.google.com/books?id=lDP4TPccgC8C&dq=%22Robert+Yerkes%22+%22expressed+doubt+that+Prince+Chim+was+a+regular+chimp%22%22&pg=PA30 |url-status=live }}</ref>

Bonobos and chimpanzees are the two species which make up the [[genus]] ''[[Pan (genus)|Pan]]'', and are the closest living relatives to humans (''Homo sapiens'').<ref name="Takahata1995">{{cite journal | vauthors = Takahata N, Satta Y, Klein J | title = Divergence time and population size in the lineage leading to modern humans | journal = Theoretical Population Biology | volume = 48 | issue = 2 | pages = 198–221 | date = October 1995 | pmid = 7482371 | doi = 10.1006/tpbi.1995.1026 | doi-access = free | bibcode = 1995TPBio..48..198T }}</ref><ref name="ChimpGenome">{{cite journal | vauthors = Waterson RH, Lander ES, Wilson RK | collaboration = Chimpanzee Sequencing Analysis Consortium | title = Initial sequence of the chimpanzee genome and comparison with the human genome | journal = Nature | volume = 437 | issue = 7055 | pages = 69–87 | date = September 2005 | pmid = 16136131 | doi = 10.1038/nature04072 | doi-access = free | bibcode = 2005Natur.437...69.}}</ref>

According to studies published in 2017 by researchers at [[The George Washington University]], bonobos, along with common chimpanzees, split from the human line about 8 million years ago; moreover, bonobos split from the common chimpanzee line about 2 million years ago.<ref name="GWU-20170505">{{cite news  |author=Staff |title=Bonobos May Resemble Humans More Than You Think - A GW researcher examined a great ape species' muscles and found they are more closely related to humans than common chimpanzees. |url=https://gwtoday.gwu.edu/bonobos-may-resemble-humans-more-you-think |date=5 May 2017 |work=[[The George Washington University]] |url-status=live |archive-url=https://archive.today/20230414135148/https://gwtoday.gwu.edu/bonobos-may-resemble-humans-more-you-think |archive-date=14 April 2023 |access-date=14 April 2023}}</ref><ref name="SR-20170404">{{cite journal |last1=Diogo |first1=Rui |last2=Molnar |first2=Julia L. |last3=Wood |first3=Bernard |title=Bonobo anatomy reveals stasis and mosaicism in chimpanzee evolution, and supports bonobos as the most appropriate extant model for the common ancestor of chimpanzees and humans |journal=[[Scientific Reports]] |date=4 April 2017 |volume=7 |number=608 |page=608 |doi=10.1038/s41598-017-00548-3 |pmid=28377592 |pmc=5428693 |bibcode=2017NatSR...7..608D |s2cid=256924135 }}</ref>

Nonetheless, the exact timing of the [[chimpanzee–human last common ancestor|''Pan''–''Homo'' last common ancestor]] is contentious, but DNA comparison suggests continual interbreeding between ancestral ''Pan'' and ''Homo'' groups, post-divergence, until about 4 million years ago.<ref name=Patterson2006>{{cite journal | vauthors = Patterson N, Richter DJ, Gnerre S, Lander ES, Reich D | title = Genetic evidence for complex speciation of humans and chimpanzees | journal = Nature | volume = 441 | issue = 7097 | pages = 1103–8 | date = June 2006 | pmid = 16710306 | doi = 10.1038/nature04789 | s2cid = 2325560 | bibcode = 2006Natur.441.1103P }}</ref> DNA evidence suggests the bonobo and common chimpanzee species diverged approximately 890,000–860,000 years ago following separation of these two populations possibly because of acidification and the spread of savannas at this time. Currently, these two species are separated by the Congo River, which had existed well before the divergence date, though ancestral ''Pan'' may have dispersed across the river using corridors which no longer exist.<ref name="Won2004">{{cite journal | vauthors = Won YJ, Hey J | title = Divergence population genetics of chimpanzees | journal = Molecular Biology and Evolution | volume = 22 | issue = 2 | pages = 297–307 | date = February 2005 | pmid = 15483319 | doi = 10.1093/molbev/msi017 | doi-access = free }}</ref> The first ''Pan'' fossils were reported in 2005 from the [[Middle Pleistocene]] (after the bonobo–chimpanzee split) of Kenya, alongside early ''Homo'' fossils.<ref name="McBrearty2005">{{cite journal | vauthors = McBrearty S, Jablonski NG | title = First fossil chimpanzee | journal = Nature | volume = 437 | issue = 7055 | pages = 105–8 | date = September 2005 | pmid = 16136135 | doi = 10.1038/nature04008 | s2cid = 4423286 | bibcode = 2005Natur.437..105M }}</ref>

According to A. Zihlman, bonobo body proportions closely resemble those of ''[[Australopithecus]]'',<ref>{{cite journal | vauthors = Zihlman AL, Cronin JE, Cramer DL, Sarich VM | title = Pygmy chimpanzee as a possible prototype for the common ancestor of humans, chimpanzees and gorillas | journal = Nature | volume = 275 | issue = 5682 | pages = 744–6 | date = October 1978 | pmid = 703839 | doi = 10.1038/275744a0 | bibcode = 1978Natur.275..744Z | s2cid = 4252525 }}</ref> leading evolutionary biologist [[Jeremy Griffith]] to suggest that bonobos may be a living example of our distant human ancestors.<ref>{{cite book |vauthors=Griffith J |author-link=Jeremy Griffith |year=2013 |title=Freedom Book 1 |chapter=Part 8:4H Humans’ development of integration through love-indoctrination and mate selection |publisher=WTM Publishing & Communications |isbn=978-1-74129-011-0 |chapter-url=http://www.worldtransformation.com/freedom-book1-integration-through-love-indoctrination/ |access-date=2013-03-28 |archive-date=2014-12-19 |archive-url=https://web.archive.org/web/20141219052145/http://www.worldtransformation.com/freedom-book1-integration-through-love-indoctrination/ |url-status=live }}</ref> According to Australian anthropologists Gary Clark and [[Maciej Henneberg]], human ancestors went through a bonobo-like phase featuring reduced aggression and associated anatomical changes, exemplified in ''[[Ardipithecus ramidus]]''.<ref name="Clark & Henneberg 2015">{{cite journal |doi=10.1515/anre-2015-0009 |title=The life history of ''Ardipithecus ramidus'': A heterochronic model of sexual and social maturation |journal=Anthropological Review |volume=78 |issue=2 |pages=109–132|year=2015 | vauthors = Clark G, Henneberg M |doi-access=free }}</ref>

The first official publication of the sequencing and assembly of the bonobo genome was released in June 2012. The genome of a female bonobo from [[Leipzig Zoo]] was deposited with the [[International Nucleotide Sequence Database Collaboration]] (DDBJ/EMBL/GenBank) under the EMBL accession number AJFE01000000<ref>{{cite journal | vauthors = Prüfer K, Munch K, Hellmann I, Akagi K, Miller JR, Walenz B, Koren S, Sutton G, Kodira C, Winer R, Knight JR, Mullikin JC, Meader SJ, Ponting CP, Lunter G, Higashino S, Hobolth A, Dutheil J, Karakoç E, Alkan C, Sajjadian S, Catacchio CR, Ventura M, Marques-Bonet T, Eichler EE, André C, Atencia R, Mugisha L, Junhold J, Patterson N, Siebauer M, Good JM, Fischer A, Ptak SE, Lachmann M, Symer DE, Mailund T, Schierup MH, Andrés AM, Kelso J, Pääbo S | display-authors = 6 | title = The bonobo genome compared with the chimpanzee and human genomes | journal = Nature | volume = 486 | issue = 7404 | pages = 527–31 | date = June 2012 | pmid = 22722832 | pmc = 3498939 | doi = 10.1038/nature11128 | bibcode = 2012Natur.486..527P }}</ref> after a previous analysis by the [[National Human Genome Research Institute]] confirmed that the bonobo genome is about 0.4% divergent from the chimpanzee genome.<ref name="Karow2008">{{cite web |vauthors=Karow J |date=2008-05-13 |title=Neandertal, bonobo genomes may shed light on human evolution; MPI, 454 preparing drafts |publisher=Genome Web |work=In Sequence |url=http://www.genomeweb.com/sequencing/neandertal-bonobo-genomes-may-shed-light-human-evolution-mpi-454-preparing-draft |access-date=2011-12-08 |archive-date=2012-01-18 |archive-url=https://web.archive.org/web/20120118184736/http://www.genomeweb.com/sequencing/neandertal-bonobo-genomes-may-shed-light-human-evolution-mpi-454-preparing-draft |url-status=live }}</ref>

=== Genetics and genomics ===
{{Infobox genome
| taxId = 10729
| ploidy = diploid
| chromosomes = 24 pairs
| size = 2,869.21 Mb
| year = 2012, 2021
}}
Relationships of bonobos to humans and other [[ape]]s can be determined by comparing their [[gene]]s or whole [[genome]]s. While the first bonobo genome was published in 2012,<ref>{{Cite journal|last1=Prüfer|first1=Kay|last2=Munch|first2=Kasper|last3=Hellmann|first3=Ines|last4=Akagi|first4=Keiko|last5=Miller|first5=Jason R.|last6=Walenz|first6=Brian|last7=Koren|first7=Sergey|last8=Sutton|first8=Granger|last9=Kodira|first9=Chinnappa|last10=Winer|first10=Roger|last11=Knight|first11=James R.|date=June 2012|title=The bonobo genome compared with the chimpanzee and human genomes|url= |journal=Nature|volume=486|issue=7404|pages=527–531|doi=10.1038/nature11128|pmc=3498939|pmid=22722832|bibcode=2012Natur.486..527P}}</ref> a high-quality reference genome became available only in 2021.<ref name="Mao-2021">{{Cite journal|last1=Mao|first1=Yafei|last2=Catacchio|first2=Claudia R.|last3=Hillier|first3=LaDeana W.|last4=Porubsky|first4=David|last5=Li|first5=Ruiyang|last6=Sulovari|first6=Arvis|last7=Fernandes|first7=Jason D.|last8=Montinaro|first8=Francesco|last9=Gordon|first9=David S.|last10=Storer|first10=Jessica M.|last11=Haukness|first11=Marina|date=2021-05-05|title=A high-quality bonobo genome refines the analysis of hominid evolution|journal=Nature|volume=594|issue=7861|pages=77–81|doi=10.1038/s41586-021-03519-x|pmid=33953399|pmc=8172381|bibcode=2021Natur.594...77M}}</ref> The overall nucleotide divergence between chimpanzee and bonobo based on the latter is 0.421 ± 0.086% for autosomes and 0.311 ± 0.060% for the X chromosome.<ref name="Mao-2021" /> The reference genome predicts 22,366 full-length protein-coding genes and 9,066 noncoding genes, although [[Complementary DNA|cDNA]] sequencing confirmed only 20,478 protein-coding and 36,880 noncoding bonobo genes,<ref name="Mao-2021" /> similar to the number of genes annotated in the [[human genome]]. Overall, 206 and 1,576 protein-coding genes are part of gene families that contracted or expanded in the bonobo genome compared to the human genome, respectively, that is, these genes were lost or gained in the bonobo genome compared to humans.<ref name="Mao-2021" />

=== Hybrids ===
Researchers have found that both central (''[[Central chimpanzee|Pan troglodytes troglodytes]]'') and eastern chimpanzees ([[Eastern chimpanzee|''Pan troglodytes schweinfurthii'']]) share more genetic material with bonobos than other chimpanzee subspecies.<ref>{{Cite news |last=Owens |first=Brian |date=2016-10-27 |title=Chimps and bonobos interbred and exchanged genes |work=New Scientist |url=https://www.newscientist.com/article/2110682-chimps-and-bonobos-interbred-and-exchanged-genes/ |access-date=2022-04-06 |archive-date=2022-01-28 |archive-url=https://web.archive.org/web/20220128162354/https://www.newscientist.com/article/2110682-chimps-and-bonobos-interbred-and-exchanged-genes/ |url-status=live }}</ref> It is believed that [[genetic admixture]] has occurred at least two times within the past 550,000 years.<ref>{{Cite web |date=2022-04-06 |title=Ancient interbreeding between chimpanzees and bonobos |url=https://cnag.crg.eu/news/ancient-interbreeding-between-chimpanzees-and-bonobos |access-date=2022-04-06 |website=cnag.crg.eu |archive-date=2020-12-31 |archive-url=https://web.archive.org/web/20201231062259/https://www.cnag.crg.eu/news/ancient-interbreeding-between-chimpanzees-and-bonobos |url-status=dead }}</ref> In modern times hybridization between bonobos and chimpanzees in the wild is prevented as populations are [[Allopatric speciation|allopatric]] and kept isolated on different sides of the Congo river.<ref>{{Cite web |last=Jewett |first=Katie |date=2017-04-25 |title=The Great Divide |url=https://www.biographic.com/the-great-divide/#:~:text=The%20Congo%20River%20separates%20the,this%2C%20the%20world's%20deepest%20river. |access-date=2022-04-06 |website=www.biographic.com |archive-date=2022-05-23 |archive-url=https://web.archive.org/web/20220523204316/https://www.biographic.com/the-great-divide/#:~:text=The%20Congo%20River%20separates%20the,this%2C%20the%20world's%20deepest%20river. |url-status=live }}</ref>

Within captivity, hybrids between bonobos and chimpanzees have been recorded. Between 1990 and 1992, five pregnancies were conceived and studied between a male bonobo and two female chimpanzees. The two initial pregnancies were aborted because of environmental stressors. The following three pregnancies however led to the birth of three hybrid offspring.<ref>{{Cite journal |last1=Vervaecke |first1=Hilde |last2=Elsacker |first2=L. van |date=1992 |title=Hybrids between common chimpanzees (Pan troglodytes) and pygmy chimpanzees (''Pan paniscus'') in captivity |journal=Mammalia |volume=56 |issue=4 |pages=667–669 |issn=1864-1547 |access-date=2023-12-01 |url=https://www.researchgate.net/publication/272356540 |archive-date=2024-03-09 |archive-url=https://web.archive.org/web/20240309175202/https://www.researchgate.net/publication/272356540_Hybrids_between_common_chimpanzees_Pan_troglodytes_and_pygmy_chimpanzees_Pan_paniscus_in_captivity |url-status=live }}</ref>

A bonobo and chimpanzee hybrid called Tiby was also featured in the 2017 Swedish film ''[[The Square (2017 film)|The Square]]''.<ref>{{Cite book |last=Foundation |first=Arcus |title=Killing, Capture, Trade and Ape Conservation: Volume 4 |publisher=Cambridge University Press |date=2021-04-29 |isbn=9781108487948 |pages=111}}</ref> This same male bonobo and female chimpanzee had several offspring.<ref>Bonobo-chimpanzee Hybrids, Pan paniscus × Pan troglodytes, "EUGENE M. MCCARTHY, PHD GENETICS, ΦΒΚ", https://www.macroevolution.net/bonobo-chimpanzee-hybrids.html</ref><ref>Pan continuity: bonobo-chimpanzee hybrids., Hilde Vervaecke1,2, Jeroen Stevens1,2 Linda Van Elsacker 1,2, "1 University of Antwerp, Department of Biology, Universiteitsplein 1, B-2610 Wilrijk, Belgium, bisonobo@skynet.be.", "2 Royal Zoological Society of Antwerp, Centre for Research and Conservation, K. Astridplein 26, B-2018 Antwerp, Belgium.", https://lirias.kuleuven.be/retrieve/518289</ref>