Zihlman's 'pygmy chimpanzee hypothesis'

I think you are right in terms of anatomy, Darren, but the behavioral version of the "pygmy chimpanzee hypothesis" still hangs around. The bonobo is often popularly presented as being more "peaceful" than Pan troglodytes and therefore is more attractive to some ethologists/primatologists as a model for early human origins. If our ancestors were violent (like in Raymond Dart's vision of the australopithecines) then our ancestry makes sense of our violent actions today, but if our ancestors were peaceful then our violence is unnatural. This juxtaposition gives the bonobo a popular appeal; would you rather be descended from violent, brutish apes or peaceful ones that made love, not war?

In this sense either the common chimpanzee or bonobo is still though to represent our ancestral state and we have to choose between them. I don't think that is the case at all (it seems to me that it has more to do with how we want to see ourselves than actual science), but it still pops up in popular books and articles now and then. If I recall correctly, Frans de Waal has been one of the biggest proponents of the idea that bonobos more closely approach our ancestral behavioral state.

I've read about this bonobo stuff before. My question is, are Bonobos really as 'peaceful' as they're made to sound? I mean, I'm no expert, but they can't possibly be that terribly different from common chimps, can they?

Cale; Bonobos and chimpanzees are very similar. There are some definite anatomical and behavioral differences, but the disparity between them isn't so wide as the "peaceful ape" vs. "brutal chimpanzee" caricatures that often come up.

Additionally, there is still much we do not know about bonobos. Unfortunately the study populations are in areas that are politically unstable and so it has been difficult to study populations over long periods of time. Many behavioral observations have been made in zoos, but we are still learning about how wild bonobos behave. The fact that bonobos in some populations catch, kill, and eat monkeys is a good example. During the past two years several papers have come out of observations made at the Lui Kotale site in the Congo in which there has been direct evidence that bonobos eat other primates (as chimpanzees do) in addition to terrestrial mammals. The bonobos at Lui Kotale, especially, seem to capture animal prey as often as some populations of common chimpanzees do, something that was not expected.

The big question that remains, as far as I am aware, is how groups of bonobos interact with other local groups. Such encounters are rare, and though the ones that have been observed have not resulted in bloodshed it should also be remembered that Jane Goodall studied the Gombe chimpanzees for years before she saw that kind of violence that would change our understanding of chimpanzees (they, too, were initially thought to be peaceful, fruit-eating apes that did not kill their own kind). Bonobos may indeed be less likely to kill members of neighboring groups, but this requires more study to determine. Overall, though, I think the idea that bonobos are more "peaceful" is largely an invention of people who would prefer to see them, rather than common chimpanzees, as models for our ancestors.

Brian's views echo those of Craig Stanford. See, for example...

Stanford, C. B. 2000. The brutal ape vs. the sexy ape? American Scientist 88, 110-112.

Stanford noted data which indicates bonobos are not obviously more sexual than chimps, that about half of the inter-community encounters observed in one population were aggressive, and that extensive meat-eating and meat-sharing have now been observed in bonobos.

Before there was much genetic evidence bearing on this, I was looking in the literature for anything on whether bonobos originated as hominin-chimp hybrids; the other pigmy chimpanzee hypothesis.

It seemed it could explain those morphological characters in which paniscus is intermediate between troglodytes (and Gorilla) and us, but also ways in which it is more extreme than either. The putative hybrid would likely be descended from individuals of each ancestral species with the least degree of xenophobic hostility and lowest threshold for sexual activity. Elegant, huh?

I guess the genome projects have busted the idea, but I haven't seen it explicitly tested anywhere, even by Patterson et al. (Genetic evidence for complex speciation of humans and chimpanzees, Nature 441: 1103-1108, 2006). Surely someone else must have thought of it too?

extensive meat-eating and meat-sharing have now been observed in bonobos.

While meat-eating presumably implies violence at some point, meat-sharing surely qualifies as a peaceful activity.

John - the most recent article I have seen on the fenomic aspects of the issue is here. I'm sure there have to be others more recent than 2005 though.

A good point indeed, Laelaps (#1). However, if the common ancestor of Pan and Homo was of a "violent behaviour", then the bonobos have evolved also from them, and so their "non-violent behaviour" is somewhat "unnatural". In any case, to reduce the complexity of Pan or Homo to violence-nonviolence behaviour is very "violent" from a theoretical point of view. But it is obvious that ideology plays an important role in the diffusion of otherwise legitimate points of view.

Laelaps: Thank you for your answer, I found it enlightening. I remember in my (relatively recent) youth alot of documentaries that highlighted the extreme sexual behavior of the bonobo along with the 'they make love, not war' type of image that I'm sure is familiar to everyone here by now. It always seemed a little odd to me, and I'm not surprised to find out that it's greatly exaggerated.

I'm partial to a weaker version of the bonobo hypothesis -- they might be a good model for the paniscus-troglodytes concestor.

On another note, how much of the behavioral difference between Pan troglodytes and Pan paniscus is culturally vs. genetically determined?

I recall seeing a news release a year or so ago stating that some anthropologist I had heard of argued that chimps are more derived than humans. If so, this suggests to me that the last common ancestor might have been more human-like than usually thought. Sorry I don't recall the details.

Agree that the relationship to human ancestry is not too strong regarding Bonobos but I have always wondered why they are so much like chimps but yet different from chimps in just the way they are reported to be and look to be from populations I've seen in photos, videos and in zoos.
A thought experiment that I've pondered some for time is to ask myself; 'what would happen if researchers purposely selected chimps for a breeding program using similar protocols to the ones use by those well-known fox breeders in Siberia some time ago who selected foxes which displayed a lower level of agression or fear of human handlers, and bred them with each other in hopes of getting a strain of foxes that were easier to handle, and instead of exactly what they thought they'd get they observed the foxes over several generations develope a suite of characteristics like floppy ears, spotted coats, curly tails and would bark like dogs while remaining less agressive and more social?'
Is neotony the right term for this or is there some other technical term for it?
I can image chimps becoming less robust, more gracile, and perhaps less hardwired or hormonally driven for physical dominance and/or aggression, and maybe more attached to the females, the mothers, in their less agressive but none-the-less still chimp social insticts; in short becoming more bonobo-like and approximating what we recognize as a having the morphology and behaviors more commonly associated in Bonobos. I guess that's not really a genuine thought experiment since one could actually conduct an experiment like that. I suppose if one proposed to select only very aggressive chimps or more aggressive Bonobos if such a variation existed in Bonobo 'society', in contrast, it might be really hard to actually handle them in captivity to even observe them using regular Chimp or Bonobo handling methods. And using humans would of course be unethical even if possible. But I remain very curious about it as I continue to read about how so much more of human behavior does seem to have a genetic connection than we used to think.

Jim: I too have read that since the discovery that Ardipithicus ramidus is such an old species, that it may show that the last common ancestor of humans and chimps may have been a larger, bipedal ape, rather than a chimpanzee-like animal.

I have a friend who studied the pelvises of hominins (A. africanus) in an African Musuem. I asked her what she thought the live animals looked like and she shrugged and said 'bonobos, with a better posture - most of the time'. The idea that chimps are less derived than us is a sort of species bias meme - I have asked lots of scientifically informed colleagues (not necessarily palaeoanthropologists) what they thought a common ancestor of chimps and humans looked like and the commonest answer is 'chimp-like'. The idea that it might be more human in posture or facial features gives people an existential shiver, even if they are atheists. Similarly, when The Guardian posted an article on Ardi the writer used the word 'woman' to refer to the fossil, which raised a lot of argument in the comments section - valid on the most part (I don't think he/she should have used the word woman for Ardi), but also in a kind of knee jerk exclusive way.

John Scanlon, FCD:

anything on whether bonobos originated as hominin-chimp hybrids; the other pigmy chimpanzee hypothesis....Patterson et al. (Genetic evidence for complex speciation of humans and chimpanzees, Nature 441: 1103-1108, 2006)

I remember that paper. It did influence me because even though it actually made few claims on the exact dating of the human/chimp split, it did confidently claim there were two splitting events, separated by about 2mys. Since then Iâve been scanning the human ancestry charts to see where that 2mys could fit in.

Luckily the other day I happened to walk past a TREE on a library trolley containing:
âDoubts about complex speciation between humans and chimpanzeesâ
Daven C. Presgraves and Soojin V. Yi
Trends in Ecology and Evolution Vol.24 No.10
doi:10.1016/j.tree.2009.04.007 Available online 5 August 2009 ,
...which claimed this supposed 2my gap didnât exist, and was just an artefact of the way the X chromosome evolves. (Our X chromosome is supposed to be much more similar to chimpsâ than the other chromosomes, and was supposed by Patterson et al. to have been a legacy of the later split.)

If so, it seems the Patterson et al. paper didnât contain any useful conclusions at all! (...except its experimental data of course.)

Human/chimp split date of approx. 4mys is still fine. That would be just after we (and chimps) went from Ardipithecus upright feet to human upright feet. As far as I know the chimp/bonobo molecules suggest a simple fairly recent split...though I too have wondered about it :-) . Still not sure about Oliver the Upright Chimp though.

Oliver was undoubtedly a member of the species Pan troglodytes. He and another bipedal chimp (Poko) 'merely' show that the features allowing obligate bipedalism in hominids are linked to the life history of the individual, and his other unusual features were the result of conditioning, deformity and a long life in captivity. Oliver has been discussed here a few times before, start with this article.

When compared to other hominoids, Sahelanthropus had 14 cranio-dental similarities with Australopithecus and 10 cranio-dental similarities with Homo. But Sahelanthropus had only 5 cranio-dental similarities with the gorilla and chimpanzee, 4 with the orangutan, and just 3 with the gibbon. So Sahelanthropus was clearly most similar to the hominins-- especially Australopithecus.

More here.

Sounds great. Now let's just hope all those shared similarities are in fact derived, and not retained from an earlier common ancestor and lost in the other apes.

More interesting would be selecting chimps for intelligence and calm behaviour over some generations.

Good topic for a sci-fi story, unfortunately slow breeding of apes would make such project unpractical.

Jerzy:

intelligence and calm behaviour

Empirical observations suggest that that combination of characters is pretty rare in the species Homo sapiens too...

Jerzy: Crichton's Congo features selectively bred 'guard gorillas', but they're bred for aggression, not docility. I say this only having seen the piss-poor movie: I haven't read the book.

"Jerzy: Crichton's Congo features selectively bred 'guard gorillas', but they're bred for aggression, not docility. I say this only having seen the piss-poor movie: I haven't read the book."

Don't bother: the movie is an accurate reflection of its source material!

The book was pretty piss-poor too (I haven't seen the movie). If I recall correctly, it was at least implied if not actually stated in the book that part of the process of breeding greater aggression involved cross-breeding with humans. "If we knew what we are, we should do as Sir Arthur Jermyn did".

One favourite fact about the movie Congo: the 'Congolese' birds that can be heard calling in the background (this is in the scene where they set up the laser perimeter fence) are British rooks!

Incidentally - - if anyone is watching the new HBO series True Blood (set in Louisiana), lots of the background bird noises also seem to feature European species. Years ago there was a big hoo-haa when a BBC period drama set in Victorian Britain had bee-eater calls playing in the background. Turns out the BBC have used this soundtrack a lot - it also features in Last of the Summer Wine. Not that I ever watch period dramas or Last of the Summer Wine, you understand.

Darren:

a BBC period drama set in Victorian Britain had bee-eater calls playing in the background.

Not to defend the indefensible, but that would actually be at least hypothetically possible. Years ago, there was another BBC, er, period drama that featured a coati in what was supposed to be an Early Cretaceous setting...

If I recall correctly, it was at least implied if not actually stated in the book that part of the process of breeding greater aggression involved cross-breeding with humans.

In the book, the new apes are suspected to be gorilla-chimp hybrids. I forgot what comes out of this (except for the stupid researcher Elliot dreaming of naming the species Gorilla elliotensis... why didn't Crichton ever write about things he knew anything about...), but humans are not thought to have participated.

Haven't seen the film.

That's interesting (the hybridisation bit), if only because the alleged presence of apes intermediate between gorillas and chimps has been a staple source of discussion 'on the fringes', as it were, since the early 1900s at least. For a good review see...

Shea, B. T. 1984. Between the gorilla and the chimpanzee: a history of debate concerning the existence of the kooloo-kamba or gorilla-like chimpanzee. Journal of Ethnobiology 4, 1-13.

However, I doubt that Crichton knew of this stuff. I've also heard it said that the apes in the original Tarzan of the Apes were neither gorillas nor chimps, but a third 'intermediate' species. This would be easy to check but I'm working to a deadline here...

Darren:

I've also heard it said that the apes in the original Tarzan of the Apes were neither gorillas nor chimps, but a third 'intermediate' species.

That's right, Tarzan's apes were a separate species. They are larger than a large human male, and are thus not chimpanzees*, but they're specifically not gorillas either (Tarzan's apes and gorillas are mortal enemies). And the impression I got when I read those books - admittedly eons ago - was that Tarzan's apes were not "intermediate" between gorillas and chimps, but rather "superior" to both of these, at least in terms of intelligence.

* I'm not sure if chimpanzees are ever actually mentioned in the Tarzan novels. Bonobos, incidentally, were not really known to westerners at the time when Burroughs wrote his earliest and most famous Tarzan novels. The bonobo wasn't described as a separate taxon until 1929.

The bonobo wasn't described as a separate taxon until 1929.

However... Troglodytes niger var. marungensis, named by Noack (1887), was argued by Thompson (2001) to be the same thing as the bonobo - i.e., a senior synonym of P. panicus. Various chimps sent to Europe prior to 1929 were labelled as marungensis and, if Thompson (2001) is correct, these were bonobos, so bonobos were both (1) 'known' to European scientists and (2) labelled with a scientific name long prior to 1929. You'll know that Kingdon draws attention to this in his field guide. However...

Groves has since shown that marungensis is a form of P. troglodytes (a subspecies, according to him), and he noted that Thompson now agrees.

Refs - -

Groves, C. 2005. Geographic variation within Eastern Chimpanzees (Pan troglodytes cf. schweinfurthii Giglioli, 1872). Australian Primatology 17, 19-46.

Noack, T. 1887, Beiträge zur Kenntnis der Säugethier-Fauna von Ost- und Central Afrika. Zoologische Jahrbücher 2, 289-302.

Thompson, J. M. 2001. On the nomenclature of Pan paniscus. Primates 42, 101-111.

"The bonobo wasn't described as a separate taxon until 1929."

Doesn't this raise the possibility that individuals like Oliver and other "odd" captive chimps may, if they have captive-bred pedigrees stretching back far enough, actually be chimp/bonobo hybrids?

(I don't know anything about the history of captive breeding in apes, but i'm thinking of parallel situations to the inter-subspecific hybrid status of most captive lions and tigers...)

As to fictional and cryptid apes... Christopher Taylor, thanks for being someone else who realised that Congo was a rip-off of Arthur Jermyn. I do remember the possibility of humans as well as chimps and gorillas being in the "guard apes"' ancestry being mentioned in Congo, but it's a very long time since i read it. The book and film were both pretty awful.

I read somewhere that Burroughs's "apes" who raised Tarzan were intended to be, though never explicitly named as, a relict population of Paranthropus or some other "robust australopithecine" type... though whether Burroughs knew enough paleontology for that to be plausible, i don't know (as his "dinosaurs" and "pterosaurs" were pretty ludicrous)...

I've seen photos of an ape in an African zoo purported to be a chimp/gorilla hybrid - it *could* just have been an odd-looking chimp (and there wasn't much of a scale bar), but it did look distinctly unusual enough that hybrid status might have been a possibility. Can't remember what part of Africa it was in. Also, what happened with that supposed "giant" (200lb+ according to some reports) population of chimps in the DR Congo that were initially described as either a possible new species or possible chimp/gorilla hybrids? IIRC, they were found to be chimps, but i don't know if the giant size was real or exaggeration...

However, I doubt that Crichton knew of this stuff.

Why?

thanks for being someone else who realised that Congo was a rip-off of Arthur Jermyn.

Can't find any similarities beyond 1) an ape civilization in deepest, darkest Africa, 2) those apes having white⦠hair.

I also don't quite get why Arthur Jermyn then kills himself, and that in such a drastic mannerâ¦

Shiva:

Doesn't this raise the possibility that individuals like Oliver and other "odd" captive chimps may, if they have captive-bred pedigrees stretching back far enough, actually be chimp/bonobo hybrids?

Captive hybrids between common chimpanzees and bonobos are known (Vervaecke & Van Elsacker, 1992); apparently, there is nothing particularly spectacular about them. They certainly don't habitually walk on their hindlegs in the way that Oliver does/did.

I read somewhere that Burroughs's "apes" who raised Tarzan were intended to be, though never explicitly named as, a relict population of Paranthropus or some other "robust australopithecine" type

Tarzan's apes were already introduced in the first Tarzan novel, Tarzan of the Apes, which was published in 1912. Australopithecus africanus was described in 1925, and Paranthropus robustus in 1938; Burroughs' wasn't quite that prescient. (Tarzan's apes, by the way, are not bipedal and they have long, un-australopithecine canine teeth.)

Reference:

Vervaecke, H. & Van Elsacker, L. 1992. Hybrids between common chimpanzees (Pan troglodytes) and pygmy chimpanzees (Pan paniscus) in captivity. Mammalia 56, 667-669.

Forgot to comment on this...

Burroughs's "apes"

Just to be clear: those scare quotes are not needed. Tarzan was really raised by apes. Not "ape-men", or "man-apes", but real (well, fictional) apes. Tarzan is a human* by birth but an animal by upbringing, and the conflict between these two sides of him is a leitmotif throughout Burroughs' novels.

* Specifically an English gentleman, Lord Greystoke.

On Tarzan's apes -- interestingly, the apes' name* for their own species, "mangani", also extends to humans (which, in their experience, come in two varieties: black "gomangani" and white "tarmangani"**). The apes have a separate word for gorillas: "bolgani". I don't believe chimpanzees are ever mentioned in the books.

So Tarzan's apes recognize themselves as being more human-like than gorilla-like. They're probably best visualized as gigantic chimpanzees, as in the Christopher Lambert movie. Incidentally, this is the only nontechnical term I have ever found to approximate the human-chimpanzee clade -- would dearly love to know if there are others.

Burroughs had a pretty shoddy knowledge of zoology. In many of the early books, Tarzan hunts deer in Africa. Later Burroughs realized his mistake and attempted to explain it: Tarzan was hunting antelope, but he thought of them as deer since he'd seen a picture of a deer in a picture book as a child.

* They speak a "guttural language".
** Tarzan's name shares the same prefix: "tarzan" means "white skin".

The last Tarzan book, Tarzan The Lost Adventure, by Edgar Rice Burroughs and Joe R. Lansdale, features a University of Texas expedition searching for the apes with the thought that they might be Australopithicenes. It is mentioned the Professor Chad Oliver back at UT will be most pleased with some find. I had a physical anthropology class with Chad Oliver in 1955. He, in addition to serious anthropolical work, wrote a number of interesting anthropology based novels and science fiction stories.

The language of the great apes was the basic language. It was understood by all animals. Because Tarzan knew this base language, he was able to become conversational in any human language within a few days of exposure.

Tarzan originally thought himself an ape x human hybrid. It takes Burroughs the first two Tarzan books to get this straightened out and get Tarzan and Jane married. (No, they did not live in sin!).

Tarzan's "apes" are, from the description, something a modern biologist would probably put closer to the human line than the chimp one; they seem to be a bit more bipedal than other apes. Also, they are much more gracile than, say, gorillas - a 7-foot-tall male is only 350 lbs.

Burroughs had an *extremely* shaky grasp of apes, though -- despite the fact that he clearly intended to present the mangani as more humanlike than gorillas, and closer to the human line of descent (there are a few points that seem to me to suggest Burroughs intended the mangani to be humans' ancestors), in many ways they are less intelligent than real apes - they're described as being too stupid to hunt or fight cooperatively, for example. (He also made male gorillas into raging monsters that killed all sorts of things... basically, he didn't care about accuracy at all - by the eighth book, Tarzan was fighting carnivorous triceratops...)

David Marjanovic @#32: "I also don't quite get why Arthur Jermyn then kills himself, and that in such a drastic mannerâ¦"

It's an H. P. Lovecraft story; any particular person will find a certain portion of Lovecraft's stories to be not at all frightening, because so many of them tie into Lovecraft's personal phobias and issues. Lovecraft was obsessed with ancestry and genealogy; in his worldview, that kind of revelation would overturn someone's entire identity.

It never struck me as that frightening, though, or even that significant...

The question "Tarzan of WHAT apes?" was naturally explored by Gary
Larson. Also his less known cousin, Larry of the Lemurs. ;-)

Remember that in 1920's the lives of the apes in the wild was completely unknown. All what was known were single infants exported to the zoos, which almost always died quickly. Science learned anything about gorillas and chimps in the wild only several decades later, with George Schaller and Jane Goodall.

If anybody knows details of alleged gorilla-chimp hybrids, I am always interested - remember that lineage split occured about at the time of chimp-human split.

Several bonobo-chimp hybrids were born in a circus in Belgium. They are (apparently still alive) no more bipedal AFAIK.

Just curious; any thoughts regarding the population of presumed chimps called 'bili apes'?

I also don't quite get why Arthur Jermyn then kills himself, and that in such a drastic manner

As William said, you probably don't find the revelation quite so horrible because (thankfully) you don't share Lovecraft's almost visceral racism and his resulting horror of miscegenation. Even some of his more successful stories (e.g. The Shadow over Innsmouth) are sadly dependent on this idea.

"If anybody knows details of alleged gorilla-chimp hybrids, I am always interested - remember that lineage split occured about at the time of chimp-human split."

If by "about at the time" you mean "about two million years earlier".

"Just curious; any thoughts regarding the population of presumed chimps called 'bili apes'?"

Apparently they are just large chimpanzees (Pan troglodytes schweinfurthii).

"Tarzan's 'apes' are, from the description, something a modern biologist would probably put closer to the human line than the chimp one; they seem to be a bit more bipedal than other apes."

It's looking more and more as though bipedality is the primitive trait for apes (perhaps further?), so that's not too informative.

Ah, thanks. All I knew about Lovecraft came from the Internet phenomenon of Cthulhu.

Dartian: Thanks for that. Hadn't realised that Burroughs was writing quite so early - i associate his stuff with the sort of pulp-fantasy genre that i think of as belonging mostly to the 1930s.

Jim: That book may well be it. While i don't think i've read it, it's very plausible that the thing i read making a Mangani-Paranthropus or Australopithecus connection was a review of it.

David: as William and Christopher said, Arthur Jermyn kills himself because he, reflecting Lovecraft himself, is a racist with a deep horror of hybridity and "taintedness", who has essentially discovered himself to be his own worst nightmare. The same motif (only with alien fish-people instead of apes) is repeated in the somewhat later (and IMO much better) The Shadow Over Innsmouth, but here the ending is radically different: after discovering that he is one of the hybrid monsters he has discovered the truth about, the protagonist considers killing himself, but then decides not to and instead decides to embrace his hybridity and join them - an ending Lovecraft doubtless considered even more horrific, but which i choose to reclaim (thoroughly against authorial intent) as a positive expression of biodiversity through hybridisation ;)

Jerzy: I tried to search for the picture i'd seen of the purported gorilla/chimp hybrid, but only found lots of speculative stories about the Bondo-Bili apes. (If the sizes in those reports are real, then i'd guess that they would at least have to be a new subspecies of chimp, if not a new species in the genus Pan - i'd imagine that size alone would ensure assortative mating if they did become sympatric with "normal" chimps..) From memory, the "hybrid" ape was peering out from a barred window in a mud- or plaster-covered building, had dark skin like a gorilla but rather bonobo-like facial features, and yellow/orangish eyes. I'll do a bit more searching when i get time and see if i can find it...

Gotten quite off-topic here, but for an excellent TV show that's reminiscent of The Shadow Over Innsmouth (although more directly based on Invasion of the Body Snatchers), check out Invasion, starring William Fichtner. Unfortunately, it was prematurely ended after one season, but that one season is quite good.

"If the sizes in those reports are real, then i'd guess that they would at least have to be a new subspecies of chimp, if not a new species in the genus Pan..."

Not really--look at the size variation in our own subspecies.

Shiva: I have a scan of the photo you're thinking of, will post it here when I have time. My recollection is that it did indeed look like a hybrid.

Bili apes: there are still very divergent opinions out there - please see this comment, it includes some relevant links.

Excellent, i didn't just imagine it! I was beginning to think it might be like that "Thunderbird photo"...

So, from the tree on Karl Amman's video, it looks like P. t. schweinfurthi is not meaningfully distinct from P. t. troglodytes, despite some people saying it ought to be promoted to species level. Yet the locals seem to pretty clearly describe two sympatric ape "species", separated by size and nesting habits. Could there be some weird polymorphism going on?

And i'd forgotten that i'd posted in that previous thread...

William, have a look at this depiction of the mangani by the comic creator Hal Foster. He started drawing Tarzan comics in 1929 (and continued for many years thereafter), while Burroughs was still alive and active; in other words, Foster's comics were published with Burroughs' approval. Had Burroughs wanted the mangani to look more missing-linkish, Foster would have drawn them that way. But as has been said already, Tarzan's apes really were just intended to be big, fierce, tree-living apes, in the sense of the word ape that a non-scientific person in the early 20th century would have understood it. That Burroughs' descriptions of the biology and behaviour of the mangani seem quite unrealistic to a modern reader is, of course, another matter. (For example, Burroughs didn't know that real apes use tools in the wild, but nobody else knew that in the 1910s either.)

Jim:

The language of the great apes was the basic language. It was understood by all animals. Because Tarzan knew this base language, he was able to become conversational in any human language within a few days of exposure.

True, in Burroughs' stories, Tarzan had linguistic skills that would have put even David MarjanoviÄ's to shame. There was none of that 'Me Tarzan, you Jane' gibberish in the books. As for all animals understanding that language, are you sure that was the case? I thought it was only the primates who could. (In a later book, Tarzan's son, Korak, could speak with the baboons.)

Tarzan originally thought himself an ape x human hybrid.

Indeed, for a long time, Tarzan believed that his biological mother was the female ape that raised him.

Shiva:

Hadn't realised that Burroughs was writing quite so early - i associate his stuff with the sort of pulp-fantasy genre that i think of as belonging mostly to the 1930s.

The thirties were, of course, the era of the Johnny Weissmuller films, which loom large in most people's image of Tarzan. But they were not the first adaptations of Burroughs' novels. A handful of Tarzan movies were made already in the silent film era, the first one as early as 1918. In other words, the character was both popular and well established well before the thirties.

Mike:

[Mangani] is the only nontechnical term I have ever found to approximate the human-chimpanzee clade

Blimey, that's a good observation! Has Burroughs unwittingly provided us with a vernacular name for the least inclusive clade containing Pan and Homo?

True, in Burroughs' stories, Tarzan had linguistic skills that would have put even David MarjanoviÄ's to shame.

Such as learning both reading and English from just opening an English book and staring at it. <facepalm>

(At least he doesn't learn to speak English that way.)

Tarzan spoke to elephants several times, and was understood. I'm pretty sure he was understood by other non-primates. So far as learning to read from children's books, that was Burroughs' idea of what an unfettered noble Englishman could accomplish. He also found his father's knife, and found out what it was good for when the gorilla jumped him on the way home. Jane was perplexed by someone writing her notes in English, while someone else could not talk with her. Both being Tarzan. Tarzan's first long term association with a civilized person was with a French naval officer, so he first learned to speak Frinch because the officer did not want to teach him incorrect English.

The funniest story: Col Clayton, RAF, is shot down while riding with an American B24 over Sumatra. Te crew thinks him crazy, but gradually understands that he knows what he is doing. Finally one of the crew understands, and remarks, "You are Tarzan!". Another member of the crew says, "You mean dats Johnny Weismuller?"

If you did not read a lot of Burroughs between ages of 10 and 12, your brain development suffered.

Blimey, that's a good observation! Has Burroughs unwittingly provided us with a vernacular name for the least inclusive clade containing Pan and Homo?

I've yet to find a better alternative!

I was inspired to write the idea up on my blog, here.

Sahelanthropus is clearly most similar to the hominins due to cranio-dental similarities.

Laelaps:

we are still learning about how wild bonobos behave. The fact that bonobos in some populations catch, kill, and eat monkeys is a good example. During the past two years several papers have come out of observations made at the Lui Kotale site in the Congo in which there has been direct evidence that bonobos eat other primates (as chimpanzees do) in addition to terrestrial mammals.

A recent paper by Fowler & Hohmann (2010) shows that bonobos, like the other great ape species, sometimes practise cannibalism too.

Reference:

Fowler, A. & Hohmann, G. 2010. Cannibalism in wild bonobos (Pan paniscus) at Lui Kotale. American Journal of Primatology 71, 1-6.