View source for Humanzee

{{short description|Hypothetical hybrid species}}
{{Hybridbox/lua
| name = Humanzee
| subheader = Hypothetical chimpanzee–human hybrid
| parent = Hominini
| genus1 = Homo
| species1 = sapiens
| link1 = Anatomically modern human
| genus2 = Pan
| species2 = troglodytes
| link2 = Common chimpanzee
}}
The '''humanzee''' (sometimes '''chuman''', '''manpanzee''' or '''chumanzee''') is a hypothetical [[Hybrid (biology)|hybrid]] of [[chimpanzee]] and [[human]], thus a form of [[human–animal hybrid]]. Serious attempts to create such a hybrid were made by [[Soviet Union|Soviet]] biologist [[Ilya Ivanov|Ilya Ivanovich Ivanov]] in the 1920s,<ref>{{cite web |last1=Pain |first1=Stephanie |title=The Soviet Ape-Man Scandal |url=https://www.newscientist.com/article/mg19926701-000-blasts-from-the-past-the-soviet-ape-man-scandal/ |website=The New Scientist |access-date=22 May 2024}}</ref> and possibly by researchers in [[China]] in the 1960s, though neither succeeded.

==Etymology==
The [[portmanteau]] ''humanzee'' for a human–chimpanzee hybrid appears to have entered usage in the 1980s.<ref>"If the Chinese succeed in their present attempts with artificial insemination to crossbreed a human being with a chimpanzee, producing the novel and useful 'humanzee,' it would be arguably patentable matter".  The portmanteau is older, dating to the 1920s, but then did not refer to a hybrid but to a "human-like" chimpanzee, trained to wear clothes etc.; cf. "Snooky the Humanzee", a [[Animals in film and television#Chimpanzees|chimpanzee actor]] in the 1920s. Lev Soudek, ''Structure of Substandard Words in British and American English'', Vydavatelʹstvo SAV, 1967, p. 199. [https://books.google.com/books?id=eCVAzQEACAAJ eCVAzQEACAAJ], [https://books.google.com/books?id=lvg_AAAAIAAJ lvg_AAAAIAAJ], [https://books.google.com/books?id=1_ZZAAAAMAAJ 1_ZZAAAAMAAJ] on [[Google Books]]. {{OCLC|oclc=124579}}.</ref>

== Possibility ==
The possibility of hybrids between humans and other [[ape]]s has been entertained since at least the medieval period; Saint [[Peter Damian]] (11th century) claimed to have been told of the offspring of a human woman who had mated with a non-human ape,<ref name="Damian">{{cite book |last=Damiani |first=Saint Petri |url=https://books.google.com/books?id=0MEUAAAAQAAJ&pg=PA789 |title=Chap. 29: ''De simia, et quo pacto simia capi possit.'' |year=1853 |editor=Constantinus Caietanus |series=Opus 52: De Bono Religiosi Status et Variarum Animantium Topologia |volume=145 |pages=789, 790 |language=la |quote=''Ait [Alexander papa] enim quia nuper comes Gulielmus in [[Liguria]]e partibus habitans marem habebat simiae, qui vulgo maimo dicitur, cum quo et uxor eius, ut erat impudica prorsus ac petulans, lascivius jocabatur. Nam et ego duos eius filios vidi, quos de episcopo quodam plectibilis lupa pepererat; ... cum femina fera concubuit; ... Enimvero nuper allatus est praefato papae, et simul et nobis grandiusculus quidam puer; et si jam, ut dicitur, vicennalis, tamen prorsus elinguis et maimoni forma consimilis, ita ut eodem vocabulo nuncupetur.'' ("For [ [[Pope Alexander II]] ] says that recently Count William who lived in the area of [[Liguria]] had a male ape, who was called maimo [?], with which also his wife, as she was exceedingly impudent and wanton, played in a more lascivious manner. For I also have seen two sons of hers which the punishable whore bore of a certain bishop. ... the beast mated with the woman; ... So then, according to the pope's account, at the same time as for us, a rather large boy was born; and although, as it is said, he is already 20 years old, he is still unable to speak and looks like the maimo, so he is called by that same name.") |author-link=Peter Damian |access-date=4 September 2019}}</ref> and so did [[Antonio Zucchelli]], an Italian Franciscan capuchin friar who was a missionary in Africa from 1698 to 1702,<ref>{{Cite web|url=https://books.google.com/books?id=PAI_AAAAcAAJ&pg=PA107|title=Relazioni del viaggio e missione di Congo nell'Etiopia inferiore occidentale|last1=Zucchelli|first1=Antonio|year=1712}}</ref> and Sir [[Edward Coke]] in "The Institutes of the Lawes of England".<ref>{{Cite web|url=https://archive.org/details/institutesoflaws00cokeuoft/page/59/mode/2up?ref=ol&view=theater|title = Institutes of the laws of England : Or a commentary upon Littleton, not the name of the author only, but of the law itself}}</ref> 

Chimpanzees and humans are closely related.<ref name="Prüfer-2012">{{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. |last12=Mullikin |first12=James C. |last13=Meader |first13=Stephen J. |last14=Ponting |first14=Chris P. |last15=Lunter |first15=Gerton |date=June 2012 |title=The bonobo genome compared with the chimpanzee and human genomes |journal=Nature |volume=486 |issue=7404 |pages=527–531 |bibcode=2012Natur.486..527P |doi=10.1038/nature11128 |issn=1476-4687 |pmc=3498939 |pmid=22722832}}</ref> [[List of genetic hybrids|Genetic animal hybrids]] with different chromosome numbers decrease the probability of [[Genetic viability|viable]] offspring and rarely occur in the first cross.<ref name="McCarthy-2008">{{Cite book |last=McCarthy |first=Eugene |url=https://www.macroevolution.net/support-files/forms_of_life.pdf |title=On the Origin of New Forms of Life A New Theory |publisher=macroevolution.net |year=2008 |location=United States |pages=34 }}</ref> Evolutionary biologists have found evidence that hybridization between humans and [[Chimpanzee|''Pan troglodytes'']] resulted in some varieties of [[archaic humans]].<ref name="Caparros-2021">{{Cite journal |last1=Caparros |first1=Miguel |last2=Prat |first2=Sandrine |date=2021-04-23 |title=A Phylogenetic Networks perspective on reticulate human evolution |journal=iScience |volume=24 |issue=4 |pages=102359 |doi=10.1016/j.isci.2021.102359 |pmid=33898948 |pmc=8054162 |bibcode=2021iSci...24j2359C |issn=2589-0042}}</ref><ref name="Arnold-2006">{{Cite journal |last1=Arnold |first1=Michael L. |last2=Meyer |first2=Axel |date=2006 |title=Natural hybridization in primates: one evolutionary mechanism |url=https://pubmed.ncbi.nlm.nih.gov/16945512/ |journal=Zoology (Jena, Germany) |volume=109 |issue=4 |pages=261–276 |doi=10.1016/j.zool.2006.03.006 |issn=0944-2006 |pmid=16945512|bibcode=2006Zool..109..261A }}</ref><ref name="McCarthy-2008" /><ref name="Winder-2014">{{Cite journal |last1=Winder |first1=Isabelle C. |last2=Winder |first2=Nick P. |date=2014 |title=Reticulate evolution and the human past: an anthropological perspective |url=https://pubmed.ncbi.nlm.nih.gov/24932745/ |journal=Annals of Human Biology |volume=41 |issue=4 |pages=300–311 |doi=10.3109/03014460.2014.922613 |issn=1464-5033 |pmid=24932745}}</ref> Chimpanzees and [[bonobo]]s are separate species, but hybridization has been documented.<ref>{{Cite journal |last1=Vervaecke |first1=Hilde |last2=Elsacker |first2=Van |date=January 1992 |title=Hybrids between common chimpanzees (Pan troglodytes) and pygmy chimpanzees (Pan paniscus) in captivity |url=https://www.researchgate.net/publication/272356540 |journal=Mammalia |volume=56 |pages=667–669 |via=[[ResearchGate]]}}</ref> Genetic similarity, and thus the chances of successful hybridization, is not always correlated with visual appearances. Domestication and backcrossing has been found to increase fertility in subsequent generations.<ref name="McCarthy-2008"/><ref>{{Cite book |last=Darwin |first=Charles |url=https://archive.org/details/in.ernet.dli.2015.216923/page/n193/mode/2up?q=domestication |title=The Descent of Man. |year=1896}}</ref>

All [[great ape]]s have similar genetic chromosome structure. Humans have one pair fewer chromosomes than other apes, as humans have 23 chromosome pairs, while all other apes have 24,<ref>{{Cite news |last=Hugo |first=Kristin |date=2018-02-18 |title=Could Chimps and Humans Mate? Tales of 'Humanzee' Hybrid Are Murky and Likely Impossible |work=Newsweek |url=https://www.newsweek.com/could-chimp-humans-mate-tales-humanzee-hybrids-murky-likely-impossible-796646}}</ref> with ape chromosomes 12 and 13 fused in the human genome into a large chromosome (which contains remnants of the [[centromere]] and [[telomere]]s of the ancestral 12 and 13).<ref>{{cite journal |last1=Fan |first1=Yuxin |last2=Elena |first2=Linardopoulou |last3=Friedman |first3=Cynthia |last4=Williams |first4=Eleanor |last5=Trask |first5=Barbara J. |title=Genomic Structure and Evolution of the Ancestral Chromosome Fusion Site in 2q13–2q14.1 and Paralogous Regions on Other Human Chromosomes |journal=Genome Research |date=2002 |volume=12 |issue=11 |pages=1651–1662 |doi=10.1101/gr.337602 |pmid=12421751 |pmc=187548 }}</ref><ref name=pnastt>{{cite journal |vauthors=IJdo JW, Baldini A, Ward DC, Reeders ST, Wells RA |title=Origin of human chromosome 2: an ancestral telomere–telomere fusion |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=88 |issue=20 |pages=9051–5 |date=October 1991 |pmid=1924367 |pmc=52649 |doi= 10.1073/pnas.88.20.9051|bibcode=1991PNAS...88.9051I |doi-access=free }}</ref> Chromosomes 6, 13, 19, 21, 22, and X are structurally the same in all great apes. Chromosomes 3, 11, 14, 15, 18, and 20 match among [[gorilla]]s, chimpanzees, and humans. Chimpanzees and humans match on 1, 2p, 2q, 5, 7–10, 12, 16, and Y as well. Some older references include Y as a match among gorillas, chimpanzees, and humans, but chimpanzees, bonobos, and humans have recently been found to share a large transposition from chromosome 1 to Y not found in other apes.<ref name=defphc>{{cite journal |vauthors=Wimmer R, Kirsch S, Rappold GA, Schempp W |title=Direct Evidence for a Pan–Homo Clade |journal=Chromosome Research |volume=10 |issue=1 |pages=55–61 |doi=10.1023/A:1014222311431 |year=2002 |pmid=11863072|s2cid=20147726 }}</ref><ref name="Prüfer-2012" /><ref name="Caparros-2021" /><ref name="Arnold-2006" />

The degree of chromosomal similarity among apes is roughly equivalent to that found in [[Equus (genus)|equines]]. Interfertility of horses and donkeys is common, although sterility of the offspring ([[mule]]s) is more common. Complexities and partial sterility pertain to horse–zebra hybrids, or [[zorse]]s, whose chromosomal disparity is very wide, with horses typically having 32 chromosome pairs and zebras between 16 and 23 depending on species. The [[Przewalski's horse]] (''Equus ferus przewalskii'') with 33 chromosome pairs, and the domestic horse (''E. f. caballus'') with 32 pairs, have been found to be interfertile, and produce semi-fertile offspring: male hybrids can breed with female domestic horses.<ref name=ncbicyt>{{cite journal | last1 = Chandley | first1 = AC | last2 = Short | first2 = RV | last3 = Allen | first3 = WR | title = Cytogenetic studies of three equine hybrids | journal = Journal of Reproduction and Fertility | issue = 23 | pages = 356–70 | year = 1975 | pmid = 1060807 }}</ref>

In 1977, researcher J. Michael Bedford discovered that human [[sperm]] could penetrate the protective outer membranes of a [[gibbon]] egg.<ref>{{cite journal |author=Bedford JM |title=Sperm/egg interaction: the specificity of human spermatozoa |journal=Anat. Rec. |volume=188 |issue=4 |pages=477–87 |date=August 1977 |pmid=409311 |doi=10.1002/ar.1091880407 |s2cid=19052254 }}</ref> Bedford's paper also stated that human [[spermatozoa]] would not even attach to the [[zona pellucida|zona surface]] of non-[[hominoid]] primates ([[baboon]], [[rhesus monkey]], and [[squirrel monkey]]), concluding that although the specificity of human spermatozoa is not confined to ''[[Homo sapiens]] sapiens'' alone, it is probably restricted to the [[Hominoidea]]. However, in the opposite direction of closely related species, it has been found that human sperm binds to gorilla [[oocyte]]s with almost the same ease as to human ones.<ref>{{Cite journal |pmid = 1571161|year = 1992|last1 = Lanzendorf|first1 = S. E.|title = Hemizona assay for measuring zona binding in the lowland gorilla|journal = Molecular Reproduction and Development|volume = 31|issue = 4|pages = 264–7|last2 = Holmgren|first2 = W. J.|last3 = Johnson|first3 = D. E.|last4 = Scobey|first4 = M. J.|last5 = Jeyendran|first5 = R. S.|doi = 10.1002/mrd.1080310407|s2cid = 26770937}}</ref>

Hybridization between members of different, but related genera is sometimes possible, as in the case of [[Cama (animal)|cama]] (camel and llama), [[wholphin]] ([[common bottlenose dolphin]] and [[false killer whale]]), and some [[felid hybrid]]s. Even hybridization between different [[Family (biology)|families]], as in the case of the [[sturddlefish]],{{efn|A hybrid between the [[American paddlefish]] (Family: [[Paddlefish|Polyodontidae]]) and the [[Russian sturgeon]] (Family: [[Sturgeon|Acipenseridae]]), created in a [[wiktionary:freak accident|freak lab accident]] in 2019 when Hungarian scientists attempted to induce [[gynogenesis]] in female sturgeons with paddlefish sperm.}} is possible (albeit exceedingly rare) provided the parent species are genetically similar enough to one another.<ref name="sturddlefish">{{cite news|last1=Roth|first1=Annie|title=Scientists Accidentally Bred the Fish Version of a Liger|url=https://www.nytimes.com/2020/07/15/science/hybrid-sturgeon-paddlefish.html|access-date=8 April 2024|work=[[The New York Times]]|date=15 July 2020}}</ref>

== Reports of attempted hybridization ==
There have been no scientifically verified specimens of a human–chimpanzee hybrid, but there have been substantiated reports of unsuccessful attempts to create one in the Soviet Union in the 1920s, and various unsubstantiated reports on similar attempts during the second half of the 20th century.

[[Ilya Ivanov]] was the first person to attempt to create a human–chimpanzee hybrid by [[artificial insemination]].<ref>{{cite journal |author=Rossiianov, Kirill |title=Beyond species: Il'ya Ivanov and his experiments on cross-breeding humans with anthropoid apes |journal=Science in Context |volume=15 |issue= 2|pages=277–316 |year=2002 |pmid=12467272 |doi=10.1017/S0269889702000455|s2cid=41098906 }}</ref> Ivanov outlined his idea as early as 1910 in a presentation to the World Congress of Zoologists in [[Graz]].<ref>{{cite book |last=Grant |first=John |date=2018 |title=Corrupted Science: Fraud, Ideology and Politics in Science |chapter-url=https://books.google.com/books?id=EJNcDwAAQBAJ&dq=World+Congress+of+Zoologists+%22ape%22+hybrids&pg=PT454 |location=Tucson, AZ |publisher=See Sharp Press |chapter=8: Stalinist Russia |isbn=978-1947071001 }}</ref> In the 1920s, Ivanov carried out a series of experiments, culminating in inseminating three female chimpanzees with human sperm, but he failed to achieve a pregnancy. These initial experiments took place in [[French Guinea]]. (For comparison with known [[Cama (animal)|cama]] statistics, in the case of male [[camel]]–female [[guanaco]] cross the probability that insemination would lead to pregnancy was approximately 1/6.<ref>{{cite journal|title=Hybridizing Old and New World camelids: Camelus dromedarius x Lama guanicoe.|first1=J A|last1=Skidmore|first2=M|last2=Billah|first3=M|last3=Binns|first4=R V|last4=Short|first5=W R|last5=Allen|date=7 April 1999|journal=Proceedings of the Royal Society B: Biological Sciences|volume=266|issue=1420|pages=649–656|pmid=10331286|pmc=1689826|doi = 10.1098/rspb.1999.0685}}</ref>) In 1929, he attempted to organize a set of experiments involving nonhuman ape sperm and human volunteers, but was delayed by the death of his last [[orangutan]]. The next year, he fell under political criticism from the Soviet government and was sentenced to exile in the [[Kazakh Soviet Socialist Republic|Kazakh SSR]]; he worked there at the Kazakh Veterinary-Zootechnical Institute and died of a [[stroke]] two years later.<ref name="newscientist">{{cite web|url=https://www.newscientist.com/article/mg19926701-000-blasts-from-the-past-the-soviet-ape-man-scandal/|work=New Scientist|date=20 August 2008|title=Blasts from the past: The Soviet ape-man scandal|last1=Pain|first1=Stephanie}}</ref>

In the 1970s, a performing chimpanzee named [[Oliver (chimpanzee)|Oliver]] was popularized as a possible "mutant" or even a human–chimpanzee hybrid.<ref>{{cite web|url=http://www.parascope.com/en/cryptozoo/missingLinks10.htm| title=10. Oliver the Mutant Chimp| access-date=2006-03-11 |archive-url = https://web.archive.org/web/20051228045237/http://www.parascope.com/en/cryptozoo/missingLinks10.htm <!-- Bot retrieved archive --> |archive-date = 2005-12-28}}</ref> Claims that Oliver had 47 chromosomes—midpoint between the normal 46 for humans and 48 for chimpanzees—were disproven after an examination of his genetic material at the [[University of Chicago]] in 1996.<ref>{{cite journal | journal = Science | author = Anonymous | year = 1996 | title = Mutant Chimp Gets Gene Check | doi = 10.1126/science.274.5288.727e | volume = 274 | issue = 5288 | pages = 727e–0| doi-access = free }}</ref> Oliver's cranial morphology, ear shape, freckles, and baldness fall within the range of variability exhibited by the common chimpanzee.<ref>Hill, WCO; in {{Cite book | last = Bourne | first = GH | year = 1969 | title = Anatomy, behavior, and diseases of chimpanzees (The Chimpanzee | volume = 1 | pages = 22–49 | publisher = S. Karger }}</ref>  Results of further studies with Oliver were published in the ''[[American Journal of Biological Anthropology|American Journal of Physical Anthropology]]''.<ref name=Ely>{{cite journal |vauthors=Ely JJ, Leland M, Martino M, Swett W, Moore CM |title=Technical note: chromosomal and mtDNA analysis of Oliver |journal=Am. J. Phys. Anthropol. |volume=105 |issue=3 |pages=395–403 |year=1998 |pmid=9545080 |doi=10.1002/(SICI)1096-8644(199803)105:3<395::AID-AJPA8>3.0.CO;2-Q}}</ref>

In the 1980s, there were reports of an experiment in human–chimpanzee crossbreeding conducted in [[China]] in 1967, and on the planned resumption of such experiments. In 1981, Ji Yongxiang, head of a hospital in [[Shenyang]], was reported as claiming to have been part of a 1967 experiment in Shenyang in which a chimpanzee female had been impregnated with human sperm. According to this account, the experiment was cut short by the [[Cultural Revolution]], with the responsible scientists sent off to farm labour and the three-months pregnant<ref>{{Cite web|url=https://www.newspapers.com/newspage/377494293/|title = The Baltimore Sun from Baltimore, Maryland on February 12, 1981 · 3| date=12 February 1981 }}</ref> chimpanzee dying from neglect. According to Timothy McNulty of ''[[Chicago Tribune]]'', the report was based on an article in the ''[[Wenhui Bao]]'' newspaper of [[Shanghai]]. Li Guong of the genetics research bureau at the [[Chinese Academy of Sciences]] was cited as confirming both the existence of the experiment prior to the Cultural Revolution and the plans to resume testing.<ref>"Li Guong, of the genetics research bureau of the Academy of Science treats it seriously. 'My personal view is that it is possible [...] We also did experimental work on this before the Cultural Revolution, but we were stopped. At the moment, we plan to arrange further tests.'"
Timothy McNulty, "Chinese Aim To Implant Human Sperm In Chimps", ''St. Petersburg Independent'' 12 February 1981, [https://news.google.com/newspapers?nid=950&dat=19810212&id=sbdaAAAAIBAJ&sjid=rFgDAAAAIBAJ&pg=6991,3347287&hl=en p. 19].
"Chinese May Resume Experiments to Create 'Near-Human' Ape", ''Houston Post'' (from ''Chicago Tribune''), 15 February 1981, p. 19, cited after Justin Leiber, ''Can Animals and Machines be Persons?: A Dialogue'', Hackett Publishing, 1985
[https://books.google.com/books?id=jTfsQ72qSckC&pg=PA71 p. 71].</ref>

In 2019, unconfirmed reports surfaced that a team of researchers led by [[Juan Carlos Izpisua Belmonte]] from the [[Salk Institute for Biological Studies]] in the U.S. successfully produced the first human-monkey [[Chimera (genetics)|chimera]]. Belmonte and others had previously produced pig and sheep embryos containing a small percentage of human cells. As with those embryos, the human-monkey chimeras were reportedly only allowed to develop for a few weeks. Although development was stopped prior to the formation of a nervous system or organs, avoiding more severe ethical concerns, the research was reportedly carried out in China to avoid legal issues. Due to the much larger evolutionary distance between humans and monkeys versus humans and chimpanzees, it is considered unlikely that true human-monkey hybrids could be brought to term. However, it is feasible that human-compatible organs for transplantation could be grown in these chimeras.<ref>{{cite news |url=https://www.theguardian.com/science/2019/aug/03/first-human-monkey-chimera-raises-concern-among-scientists |title=First human-monkey chimera raises concern among scientists |last=Davis |first=Nicola |work=[[The Guardian]] |issn=0261-3077 |date=2019-08-03 |access-date=2019-09-14 }}</ref>

== Evidence for early hominin hybridization ==
{{main|Hominini|Chimpanzee–human last common ancestor}}
{{further|Archaic human admixture with modern humans }}

There is evidence for a complex speciation process  for the [[Chimpanzee–human last common ancestor|''Pan''–''Homo'' split]] which may include hybridization,<ref name="McCarthy-2008" /> or what is known as [[reticulate evolution]].<ref name="Caparros-2021" /><ref name="Arnold-2006" /><ref name="Winder-2014" /> Different chromosomes appear to have split at different times, suggesting that  large-scale hybridization  may have taken place over a period of as much as four million years leading up to the emergence of the distinct human and chimpanzee lineages as late as six million years ago.<ref name="complex">{{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 |bibcode = 2006Natur.441.1103P |s2cid=2325560 }}</ref>

The similarity of the [[X chromosome]] in humans and chimpanzees might suggest hybridization taking place as late as four million years ago. However, other mechanisms such as natural selection on the X chromosome in the chimpanzee–human last common ancestor may also explain the apparent short divergence time in the X chromosome.<ref>{{cite journal |author=Wakeley J |title=Complex speciation of humans and chimpanzees |journal=Nature |volume=452 |issue=7184 |pages=E3–4; discussion E4 |date=March 2008 |pmid=18337768 |doi=10.1038/nature06805 |bibcode = 2008Natur.452....3W |s2cid=4367089 }}
"Patterson et al. suggest that the apparently short divergence time between humans and chimpanzees on the X chromosome is explained by a massive interspecific hybridization event in the ancestry of these two species. However, Patterson et al. do not statistically test their own null model of simple speciation before concluding that speciation was complex, and—even if the null model could be rejected—they do not consider other explanations of a short divergence time on the X chromosome. These include natural selection on the X chromosome in the common ancestor of humans and chimpanzees, changes in the ratio of male-to-female mutation rates over time, and less extreme versions of divergence with gene flow. I therefore believe that their claim of hybridization is unwarranted."
Wade, Nicholas. [https://www.nytimes.com/2006/05/18/science/18evolve.html?ex=1171515600&en=50ac61aa1c998951&ei=5070 "Two Splits Between Human and Chimp Lines Suggested"], ''The New York Times'', 18 May 2006. For a chromosomal homology map between these species see. {{cite journal|last=Pratas|first=D|author2=Silva, R|author3=Pinho, A|author4=Ferreira, P|title=An alignment-free method to find and visualise rearrangements between pairs of DNA sequences.|journal=Scientific Reports|date=May 18, 2015|volume=5|pmid=25984837|doi=10.1038/srep10203|page=10203|pmc=4434998|bibcode=2015NatSR...510203P}}</ref>

It is hypothesized that the peculiar features of ''[[Homo naledi]]'' may be due to them being descendants of a relatively recent hybridization event between ''Homo'' and ''[[Australopithecus]]''.<ref>{{cite journal |last1=Berger |first1=L.R. |author1-link=Lee Rogers Berger |last2=Hawks |first2=J.D. |author-link2=John D. Hawks |last3=Dirks |first3=P.H.G.M. |last4=Elliott |first4=M. |last5=Roberts |first5=E.M. |year=2017 |title=''Homo naledi'' and Pleistocene hominin evolution in subequatorial Africa |journal=[[eLife]] |volume=6 |doi=10.7554/eLife.24234 |pmid=28483041 |pmc=5423770 |doi-access=free }}</ref>

== See also ==
* [[Great ape personhood]]
* [[Human–animal hybrid]]
* [[Human evolution]]

== References ==
{{Notelist}}
{{Reflist}}

== Further reading ==

* {{Cite news |last=Villazon |first=Luis |title=Is it possible for humans and chimpanzees to interbreed? |work=[[BBC Science Focus]] |url=https://www.sciencefocus.com/nature/is-it-possible-for-humans-and-chimpanzees-to-interbreed/}}
{{Great ape language}}
{{Mammal hybrids}}

[[Category:Human hybrids]]
[[Category:Human subject research]]
[[Category:Chimpanzees]]
[[Category:Intergeneric hybrids]]
[[Category:Hypothetical life forms]]