I would recommend reading this article: Why did modern human populations disperse from Africa ca. 60,000 years ago?due  A new model  http://www.pnas.org/content/103/25/9381.long

Essentially Australopithecines are absent from the Southeast Asian fossil records because it is widely hypothesized that they evolved in Africa and only their descendants migrated out of Africa hundreds of thousands of years later.

Thanks Joshua, I  agree with you as they evolved in Africa only. South Asia was ecological unfavorable for the survival of later Miocene hominoids and certainly for the Plio-Pleistocene hominids as australopithecines. The only contentious point is which among the later Miocene hominoids was the last common ancestor of the austraolpithecines and the chimpanzee.

While some evidence suggests anthropoids evolved in Asia and then migrated to Africa, hypotheses suggest that the common ancestor to chimpanzees and australopithecines could be Sahelanthropus tchadensis, another species endemic to Africa.

By some accounts, Australopiths required at least open forests to climb to escape predators. any major gap in forest cover in NE Africa or SW Asia would have constituted a barrier to their dispersal out of Africa. It would be interesting to compile a list of animals, such as horses, that did cross into or out of Africa during the Pliocene. Do they have any ecological requirements in common? If they were mostly grassland species rather than forest dwellers that would suggest a barrier due to lack of tree cover.

Another way to look at this is that australopithecines were not in Africa because their ancestors were not in Africa. This is true of life in general. Under certain circumstances taxa may expand (or contract) their distribution, but just because something is not everywhere does not mean that it should be. 

There is nothing to my knowledge that supports Sahelanthropus being a common ancestor to chimpanzees and australopithecines. The fossil evidence supports orangutans as sharing a most recent common ancestor with hominids.

oops - I should have said not in Asia for australoptihs

I am happy that my question has provoked good reasoning and it is nice that we are  opening up our hidden viewpoints without biases since most scholars remained polarized.

During 22-27 June 2014 I attended the Tautavel palaeoanthropology conference organized by Prof Henry de Lumley during which I raised the question of Sehlanthropus to Prof M. Brunett- the founder. He with his popular open laud voice rejected all other the views on this genus and regarded it a definite  'hominid'. If it is so, where the common ancestor of Pan and Australopithecus if the latter has evolved in African continent. Then I raised the question of the LCA, but he avoided the answer.

John Grehan  with Jeffery Schwartz has been the champion of the Pongo-hominid closest  ancestry rather the Pan-hominid. I also arrived on similar conclusions in my publications of 1985, 1988, 1990, 2007, etc. although not referred by these renowned palaeoanthropologists. However, this view is diametrically opposite to the popular view and scholars of African schools have not even entertained this thought.

But, John has raised another interesting point that Australopithecus has had no African ancestry. Then where?

"oops - I should have said not in Asia for australoptihs"- John do you wish to say that australopiths are confined to Africa because their unknown ancestors were in Africa only?

My view, based on current evidence only (always a problem with fossils) is that australopiths are an allopatric fragment of a formerly widespread ancestor. If orangutans are the sister group to the living , the morphological evidence points to a widespread common ancestor ranging over parts of Africa and Eurasia that locally differentiated into allopatric descendants with the African members becoming the hominid group (australopiths and Orrorin at least, not Ardipithecus or Sahelanthropus). Interestingly there are 'australopith' teeth fossils that are labelled australopithecus, but do not conform to australopith teethin embedded in skulls, but look more orangutan-like.

Whether australopiths expanded their range outside Africa, or had an original range outside Africa that has not yet been discovered remains a possible conjecture (especially when one consider Damanisi and floresiensis).

Broadly or theoretically it sounds OK, but still quite ambiguous when we wish to identify the LCA practically. We are dealing with the available hominoid fossils, to name some having more pronounced orangutan dental features (if we accept closer  Oranguta's kinship)- such as Kenyapithecus (Africa), Ankarapithecus (Turkey), Sivapithecus (Indo-Pak) and Lefengpithecus (China)- etc. Even if they are allopatrically / regionally derived, can we lay hand on one of these for the the most near LCA for the Orangutan-australopith lineage? Or is there any other fossil hominoid less derived to be considered as the possible LCA?

Anek, it was interesting to see your description of Brunett’s loud rejection all other the views Sahelanthropus that he considered to be a definite 'hominid'. Of course he is entitled to express that view, but how he would address specific criticisms is the scientific concern. Below is a list of the problematic nature of hominid assertions presented by Grehan and Schwartz (2009). I am not aware of any published response, but this is not to say that it is not out there somewhere. Anek, I would be interested to see your papers that were not cited in Grehan & Schwartz (2009). I tried to check my reference files but due to a career distruption a couple of years back I cannot check back at this time.

Appendix S3 Problematic hominid characters for Sahelanthropus

Features proposed by Brunet et al. (2002) for recognizing Sahelanthropus as a hominid are all problematic or unsupported:

(1) “Canines that are small and apically worn.” In reference to the upper canine of the holotype Wolpoff et al. (2006) note that the canine crown size is not exceptionally small compared to Miocene apes, such as Kenyapithecus, or the extant bonobo. They also suggest that the apical wear in Sahelanthropus is comparable to that found in the Mio-Pliocene ape Gigantopithecus.

(2) “Intermediate postcanine enamel thickness”. No recognized hominid is characterized by enamel thickness intermediate between Pan and australopiths.

(3) “Length and horizontal orientation of the basicrainium”. Wolpoff et al. (2006) note that the published length of the nuchal plane exceeds all early hominid crania and that the length, breadth, and many other details of the nuchal plane are ape- rather than hominid-like.

(4) “Anterior position of the foramen magnum”. The landmark basion (on the anterior rim of the foramen magnum) in Sahelanthropus and Ardipithecus is said to be intersected by the bicarotid cord whereas it is supposed to lie posterior to the bicarotid chord in large apes and anterior to the bicarotid cord in “some” later hominids (Brunet et al., 2002). Inspection of the published photograph shows what appears to be the anterior margin of the foramen magnum lying posterior to the bicarotid cord. Comparisons with other hominoids suggests that the biporionic cord is a more constant feature from which to assess the relative position of basion; in orangutans and some monkeys basion remains close to the biporonic cord, while in various Plio-Pleistocene and later hominids basion is not always anterior to the biporionic cord and may sometimes lie behind both the bicartoid and biporionic cords (Schwartz, 2004b).

(5) “Reduced subnasal progmathism.” Brunet et al. (2002) characterize Sahelanthropus as being less prognathic than supposedly later Australopithecus. Some monkeys (especially New World) are less prognathic than some hominids.

(6) “Without canine diastema”. The elliptical contact facet for an isolated P1 is said to indicate absence of a C1-P1 diastema that is characteristic of later hominids. The C1 of the holotype is a relatively tall and caniniform tooth that would have occluded with a relatively robust P1as well as a recognizably caniniform C1. The isolated short, stubby and broadly triangular lower ‘canine’ (TM 266-02-154-2) with its basal ring of thick and slightly beaded cingulum is more similar to the small premolars of carnivores than the canine of a primate. Lack of a diastema is not characteristic of all recognized hominids, such as Australopithecus afarensis (AL 200-1a) or the holotype maxilla of A. garhi (Schwartz, 2004b).

(7) “Large continuous supraporbital torus”. This feature does not characterize any of the australopiths and only some Homo ‘erectus’. The supraorbital torus is unlike that of any other primate (Schwartz, 2004b).

http://genome.cshlp.org/content/15/12/1746.long

http://www.nature.com/nature/journal/v469/n7331/full/nature09687.html

It is of some interest that genetically speaking the genus Pongo is considered more divergent from genus Homo than the genus Pan. How could this be the case if the LCA of ancient apes and hominids was more closely related to Pongo than Pan?

And thank you for the full text of your article, John Grehan!

Great question! The term ‘genetic’ is often used for the comparison of DNA base similarities, but really the comparison of matching base similarities is really more about the morphology and position of bases than genetics as a process of inheritance. When one is looking at morphology one is indeed looking at consistent patterns of genetic inheritance and divergence. If genetics can be used for DNA molecules then one can also call morphology genetic as well (and morphogenetic in terms of a developmental process). There is the widespread view, at least in human origins study, that molecular similarity is imbued with a certain level of infallibility especially if many sequences are involved (the law of large numbers – if there are large numbers giving a certain result then it cannot possibly be wrong). This may constitute a widespread belief, but it is not an empirical fact. If the molecules are right, then the morphological patterns of similarity are rendered meaningless (as they are incongruent), and then so too is the fossil record which is entirely morphological (apart from fairly recent stuff). What a mess!

My Answer

On Sehlanthropus

John thanks for elaborating the comparative morphology of Sehlanthropus citing Wolpoff and Schwarz. I do agree, it is problematic and so you have avoided to conclude its status in human phylogeny, whether an ape, hominid (or course you denied) or the LCA of Pan and australopith. I am also confused, especially by its highly developed supraorbital torus. You also rightly brought in consideration Gigantopithecus dental wear despite of the fact of great divergence in size between the two. I would call prognathism as highly autapomorphic and very unique trait; klinorynchy (Pan-Australopithecus) and airorhynchy (Sivapithecus-Pongo) also evolved in parallel in Asian and African apes/hominids. I would conclude provisionally that Sehlanthropus is neither a ‘hominid’ nor the Pan-Austraolpith ‘LCA’, but was very unique and divergent north African hominoid as was Gigantopithecus in Asia. So, at present the African LCA is unknown.

Returning to Joshua Cannon. Thanks for your observation and for the nature links. The Borneo decline and Sumatran rise in allele diversity of the Orangutan is very interesting finding revealing how natural selection is affecting the two species which became so distinct within a short span of 400Kya. At such divergence rate, Pongo could diverge too much genetically from its Siwalik ancestor Sivapithecus with whom it shared ancestry. And from hominids as well if Sivapithecus was the LCA.

Of course, we cannot ignore or dismiss the genomic evidence to plead for morphological anatomical evidence from fossils, etc. Alternatively, we may interpret that the present higher genetic distance between Pongo and Homo could be attributed to Orangutan’s divergence accountable to the environmental-ecological contrast between Sivapithecus (Sub-Himalayan Siwalik ancestor) and Pongo (SE Asia island descendant). In fact, Pongo’s tree living (with huge body size) is also viewed as later adaptation rather than being the ancestral habitat.

Interestingly, there has been less morphological divergence between Sivapithecus and Pongo, which led to conclude Sivapithecus as “pongid”, especially in the mid face anatomy- interorbital distance and airorhynchy. But, it does possess hominid-like thick enamel on megadont molars and other associated robust dental morphologies. Sivapithecus is a unique blend of ‘homind-pongid’ features due to lumping of Ramapthecus (earlier claimed hominid) with Sivapithecus (then believed pongid). Due to this ‘hominid-pongid’ mosaic Sivapithecus may qualify as ‘Pongo-hominid’ LCA if there is no other potential candidate (Sankhyan, 2007).

My Answer

On Sehlanthropus

John thanks for elaborating the comparative morphology of Sehlanthropus citing Wolpoff and Schwarz. I do agree, it is problematic and so you have avoided to conclude its status in human phylogeny, whether an ape, hominid (or course you denied) or the LCA of Pan and australopith. I am also confused, especially by its highly developed supraorbital torus. You also rightly brought in consideration Gigantopithecus dental wear despite of the fact of great divergence in size between the two. I would call prognathism as highly autapomorphic and very unique trait; klinorynchy (Pan-Australopithecus) and airorhynchy (Sivapithecus-Pongo) also evolved in parallel in Asian and African apes/hominids. I would conclude provisionally that Sehlanthropus is neither a ‘hominid’ nor the Pan-Austraolpith ‘LCA’, but was very unique and divergent north African hominoid as was Gigantopithecus in Asia. So, at present the African LCA is unknown.

Returning to Joshua Cannon. Thanks for your observation and for the nature links. The Borneo decline and Sumatran rise in allele diversity of the Orangutan is very interesting finding revealing how natural selection is affecting the two species which became so distinct within a short span of 400Kya. At such divergence rate, Pongo could diverge too much genetically from its Siwalik ancestor Sivapithecus with whom it shared ancestry. And from hominids as well if Sivapithecus was the LCA.

Of course, we cannot ignore or dismiss the genomic evidence to plead for morphological anatomical evidence from fossils, etc. Alternatively, we may interpret that the present higher genetic distance between Pongo and Homo could be attributed to Orangutan’s divergence accountable to the environmental-ecological contrast between Sivapithecus (Sub-Himalayan Siwalik ancestor) and Pongo (SE Asia island descendant). In fact, Pongo’s tree living (with huge body size) is also viewed as later adaptation rather than being the ancestral habitat.

Interestingly, there has been less morphological divergence between Sivapithecus and Pongo, which led to conclude Sivapithecus as “pongid”, especially in the mid face anatomy- interorbital distance and airorhynchy. But, it does possess hominid-like thick enamel on megadont molars and other associated robust dental morphologies. Sivapithecus is a unique blend of ‘homind-pongid’ features due to lumping of Ramapthecus (earlier claimed hominid) with Sivapithecus (then believed pongid). Due to this ‘hominid-pongid’ mosaic Sivapithecus may qualify as ‘Pongo-hominid’ LCA if there is no other potential candidate (Sankhyan, 2007).

I might look at the concept of 'last common ancestor' slightly differently from most who deal with fossils. I do not identify any fossil as a LCA for any taxon. Rather, I may identify its inclusion within a particular group as defined by one or more characters, and within that group the fossil may have a basal position - that it is the sister taxon to all the rest. So in this regard the LCA of humans and orangutans and their fossil relatives is the set of characters that defines that clade. At present there is only one feature that has been identified for all members - relatively thick molar enamel. This is a problematic character as thickness does vary and there has not been enough comparative work for some fossils.

There are other characters that may well define the human-orangutan clade, but the features have not yet been found preserved in various fossil members. For example, there are about 3-4 dental features that are unique to the deciduous teeth of humans and orangutans, but these features are not yet described for fossil taxa (its hard enough finding a juvenile let alone with unworn teeth). Another feature is the single incisive foramen of the palate - narrow in orangutan, broad in hominids (except one juvenile australopith that has the orangutan condition). Again, this feature is poorly preserved in fossils.

One of the biggest challenges for hominid and even great ape fossil study is the relatively lack of access to the fossils - few fossil vs much interest. In some cases the finders of the fossils prevent direct access, especially if they think people might develop interpretations at odds with their own. At the very least there is the need for dissemination of very high resolution images, not the cartoon level resolution one finds in Nature articles for example. I have even approached some authors for high resolution images and of course get no reply. The study of floresiensis appears to be an notable exception with the finders giving full and widespread access and providing high quality images.

John- I understand your problem. In a cladistic phylogeny reconstruction we find only a very few novel synapomorphic characters which define closer affinities while numerous sympleisomorphies and autapomorphies are rendered meaningless. It is the basic limitation of Cladistics where we reject most of the characters. On the contrary, the traditional Gradistic analysis emphasized ‘over-all’ similarity irrespective of the primitive or derived characters.

So, you highlighted a fewer novel juvenile features and deciduous dentition in uniting human and orang-utans of course stressing ontogeny/ history, but also recognizing that they are rarely preserved in fossil record. In such considerations the fossil record becomes almost meaningless, and we shall have little fossil evidence to support either the ‘Pongo-hominid’ or ‘Pan-hominid’ theory, which generally stand on extant genomic/molecular and or morphological distances. In my opinion if we follow the “bottom up approach” and depend more on the frequently preserved adult characters in the fossil record (which I have considered in my study) when comparing Sivapithecus, Pongo and Australopithecus/hominids. It is also here that the presence of the LCA is felt. Palaeoanthropologists erect species and genera and do not consider the fossils of teeth and bones as a mere collection but assign to certain extinct group or species first and then fit them in the fossil-based phyolgentic trees, of course based on comparative morphologies.

You noted less significance of the hominoid thin enamel. But, I see it relatively a robust trait compared to several other anatomical features. Despite some variability it consistently segregates the Miocene hominoids and we can distinguish the African and European Miocene hominoids, which in general have relatively thin enamel. The same is true for the extant African apes with slight variation due to dietary habits.

On the other hand, the Eurasian and Asian hominoids are largely thick-enamelled. So are the Plio-Pleistocene hominids and Homo; the Orangutan has moderate enamel thickness (due to preference to frugivory) relative to its Pleistocene and Miocene ancestors with great thickness of the molar caps, which have provided a greater selective advantage for adaptation to a wider range of dietary regime exploiting varied habitats. Therefore, I think, the Eurasian-Asian late Miocene hominoids with thick-enamel dental apparatus were already “dental hominids” would more likely evolve to the Plio-Pleistocene hominids with some cranial and postcranial modifications.

However, if we assume a thick- enamelled common ancestor of the Pan-hominids node, we need to explain the enamel loss through secondary reduction in chimp lineage, while there is no problem for the hominid lineage to evolve further. Alternatively, why not to consider a separate early thin enamelled ancestor of the chimp-gorilla lineage like Dryopithecus?

Lastly, I agree on the possessiveness of hominoid-hominid fossils and the poor images preventing competent scholars to have access, but there are good pictures also available fair enough to reveal morphology. Thanks for sharing.

Different lines of evidence suggest australopiths were swamp forest & later wetland dwellers (Plio- & Pleistocene resp.?), who partly fed on floating vegetation & wetland foods, and were more closely related to Pan or Gorilla than to Homo, see my Hum.Evol.papers, esp.

- Australopithecines: Ancestors of the African Apes? 1994 HE 9:121-139,

- Morphological Distance between Australopithecine, Human and Ape Skulls 1996 HE 11:35-41,

- The aquatic ape evolves: Common misconceptions and unproven assumptions about the so-called Aquatic Ape Hypothesis 2013 HE 28:237-266.

Morphologically the australopith spp are a unique & rather uniform group, much nearer to the great ape morphological group (Pan, Gorilla, and even Pongo through parallel evolution) than to humans.

There's no indication that any of the australopith spp has evolved in the human direction, e.g. their thick enamel, shorter canines, vertical spine, flat footprints & other "bipedal" features etc are primitive-hominoid rather than human-derived. 

(1) South-African africanus-robustus are morphologically closest to bonobos & chimps among the living hominoids.

(2) East-African boisei-aethiopicus are closest to the living gorillas among the living hominoids.

(3) Homo evolution appears to have been very fast (i.e. derived) the last 1 or 2 million years. 

The E.Afr.apiths seem to have evolved in parallel with the S.Afr.apiths (the Plio>Pleistocene drying & cooling = from swamp forest to more open wetlands?), but the E.Afr.apiths were generally more herbi-, the S.Afr.apiths more omnivorous.

Likely IMO, the S.Afr.apiths are fossil spp of Pan, IOW, Taung was some sort of fossil "chimp" after all (vs Dart), whereas most or all E.Afr.apiths are fossil spp of Gorilla. No wonder their fossils are absent from Asia (in SE.Asia we find in parallel the "robust" Gigantopithecus as a fossil relative of Pongo). Homo OTOH "escaped" from Africa following the coasts & later rivers, e.g. see the deltaic sites of Mojokerto in Java already 1.8 Ma, where archaic Homo fossils were found amid barnacles & marine & freshwater shellfish (coastal dispersal model, see the malacological work of Stephen Munro).

Marc- thanks for your great and brief highlight on African Australopithecus spp and their closeness to African apes, which apparently have African origins. The swamp adaptation of S. African Australopithecus is quite interesting and make them closer to Gorilla in adaptive regime. So many queries come from your descriptions.

One, which Australopithecus spp is on Homo lineage? Second, Which late Miocene African hominoid links the chimps with the hominids( Homo)- a central point in the present discussion?

While I do agree with Marc on the points 1 and  2, I have yet to see any evidence that suggests that the Aquatic Ape Hypothesis holds credence. http://www.sciencedirect.com/science/article/pii/S0047248497901469

The AAH is based on observations in modern humans and marine mammals and has no foundation in paleontology, morphology, or genetics. No serious empirical study of this hypothesis has managed to find any evidence to support its claims but rather numerous refutations. The finding of early hominids along lakes, rivers, and shorelines  is due to the favorable conditions for fossilization and not due to habitat preferences. While early hominids almost certainly made use of aquatic resources, in no way does the fossil record suggest an "aquatic ape".

Early hominids could not survive for more than a couple of days without access to fresh water. This was therefore a major factor in determining their range.

It follows from this that their need for access to fresh water forced them to live in those habitats where fresh water could be found. These were hence the habitats they became best adapted to living in

In this context modern great apes are regularly seen wading waist deep in water to gain access to certain mineral rich plants.

Therefore the most radical statement in any description of the aquatic ape/waterside hypothesis is that our ancestral stock were doing much the same as great apes do today but wading out a little deeper

http://ebooks.benthamscience.com/book/9781608052448/

Lots of confusion on the initial adaptation of the hominids. Even savanna hypothesis is rejected and there is a good debate in the latest issue of Current Anthropology.

Dear Anek

Thanks for the information  -  is this the paper? 

Is the “Savanna Hypothesis” a Dead Concept for Explaining the Emergence of the Earliest Hominins?

http://www.jstor.org/stable/10.1086/674530?seq=0&uid=3738032&uid=2134&uid=2&uid=70&uid=4&sid=21104648662913

There is also an interesting debate in Advances in Anthropology - summarised in this paper by Algis Kuliukas 

Removing the “Hermetic Seal” from the Aquatic Ape Hypothesis: Waterside Hypotheses of Human Evolution

http://file.scirp.org/Html/7-1590246_48899.htm

There is as you say doubt about the very early phase and that leaves no room for dogma on either side

In that context I always rather enjoy watching this film clip of Desmond Morris explaining the AAH since it was Elaine Morgan's feminist response to his Naked Ape book that bought the whole debate into the public eye

https://www.youtube.com/watch?v=mFRYtPQfyCk

Marc,

I have not read your 1994, 1996 papers so I will check them out. But to my knowledge there is no cladistic evidence to support the contention that australopiths are phylogenetically nearer to any living ape than they are to humans (although australopiths do share a number of uniquely orangutan clade features). I am also not aware of empirical evidence to support your contention that the features such as thick enamel, shorter canines and other bipedal features are primitive hominoid rather than hominid (Humans plus closes fossil relatives). Certainly thick enamel is unique to humans and orangutans among living hominoids and among fossils thick enameled taxa are either orangutan relatives or human relatives. Humans and orangutans also share a variety of other derived features such as the single incisive foramen, the foramen lacerum, posteriorly thick palate, and several derived juvenile dental cusp characteristics.

The aquatic ape hypothesis is just like all the rest of the adaptationist hypotheses – in my opinion they are all just fantasies. Not science.

I think the CA article with CA treatment is quite exhaustive and deals with with various hypotheses. So, we may have better interactions after reading that.

Joshua, your information is very much outdated. J.Langdon's writings are also outdated & irrelevant to AAT today: Pleistocene Homo dispersed along coasts & rivers of Africa & Eurasia.  We (& A.Kuliukas apart IIRC) answered Langdon a few times, e.g. M.Vaneechoutte, S.Munro & M.Verhaegen 2012 "Reply to John Langdon’s review of the eBook: Was Man more aquatic in the past?" HOMO J.compar.hum.Biol.63: 496-503 (J.hum.Evol. without arguments systematically refuses our replies to Langdon: they "know" AAT is wrong & don't allow replies). If you send me [email protected] your email, I'll send you our reply.

Archaic Homo's coastal diaspora (AAT today) is without doubt: how else did they reach Mojokerto on Java, Dungo V in Angola & Pakesfield in England, all early-Pleistocene coastal sites: barnacles, marine shells etc. I hope you don't believe they got there running over savannas as some paleo-anthropolgoists still think?

AAT is firmly based on observations in modern humans & marine mammals, and is fully supported by paleontology, archeology, morphology, physiology & genetics, e.g. M.Verhaegen 2013 "The aquatic ape evolves: common misconceptions and unproven assumptions about the so-called Aquatic Ape Hypothesis" Hum.Evol.28:237-266.

John, I strongly advise to read M.Verhaegen 2013 "The aquatic ape evolves: common misconceptions and unproven assumptions about the so-called Aquatic Ape Hypothesis" Hum.Evol.28:237-266. 

Colin, yes, the savanna theory is dead at least since my letter to Nature 325:305-6, 1987 "Origin of hominid bipedalism": Sinclair et al.(1) believe that human bipedalism arose in scavenging hominid ancestors that had to carry their children while following migrating savanna ungulates, but this seems highly improbable.

There was no empty niche of migrating scavengers to be occupied by hominid ancestors. Not only vultures, but also canid, felid and hyaenid carnivores were much better preadapted for such a niche. They possessed sharp beaks or long canine teeth and did not need to carry stones for cutting carcasses. Moreover, the bipedal way of locomotion – whether fast or slow – is inefficient and costly (2,3).

Another argument against the migrating hypothesis in particular and the savannah theory of human evolution in general is that it is highly unlikely that hominid ancestors ever lived in the savannas. Man is the opposite of a savanna inhabitant. Humans lack sun-reflecting fur (4), but have thermo-insulative subcutaneous fat layers, which are never seen in savanna mammals. We have a water- and sodium-wasting cooling system of abundant sweat glands, totally unfit for a dry environment (5). Our maximal urine concentration is much too low for a savanna-dwelling mammal (6). We need much more water than other primates, and have to drink more often than savanna inhabitants, yet we cannot drink large quantities at a time (7-8). The fossils of our hominid ancestors or relatives are always found in water-rich environments.

It is difficult to understand why most anthropologists keep believing in the savanna theory (possibly because it goes back to Darwin), or why so many anthropologists keep trying to seek the most improbable reasons for bipedalism, while they should know there are much better explanations (9-11).

1. Sinclair, A. R. E., Leakey, M. D. & Norton, M. Nature 324, 307 (1986).

2. Washburn, S. L. & Moore, R. Ape Into Human, 77-78 (Little, Brow and Company, Boston, 1980).

3. Wheeler, P. E. J. Hum. Evol. 13, 91 (1984).

4. Macfarlane, W. V. in Adaptations of Domestic Animals (ed. Hafez, E.) 164-182 (Lea and Febifer, Philadelphia, 1968).

5. Montagna, W. in Biological Anthropology (ed. Katz, S. H.) 341-351 (Freeman, San Francisco, 1975).

6. McFarland, W.N., Pough, F.H., Cade, T.J. & Heiser, J. B. Vertebrate Life, 674 (Collier Macmillan, London,1979).

7. McFarland, D. Animal Behaviour, 267 (Pitman, London, 1985).

8. Schmidt-Nielsen, K. Desert Animals, 67 (Dover Publications, New York, 1979).

9. Hardy, A. C. New Scient. 7, 642 (1960).

10. Morgan, E. The Aquatic Ape (Souvenir, London, 1982).

11. Verhaegen, M. J. B. Med. Hypotheses 16, 17 (1985).

Anek, if possible, could you send me [email protected] the Curr.Anthr.papers on the savanna hypothesis? Thanks a lot.

Anek, you ask "which Australopithecus spp are on Homo lineage?"  In fact, I don't think any known australopith species is a closer relative of Homo than of Pan & a fortiori of Gorilla, although IMO the S.African australopiths are closer relatives of Pan & therefore also of Homo than of Gorilla.  I do think that our ancestors looked more like australopiths than like extant apes (living apes are derived, although in different directions than we are).

"Which late Miocene African hominoid links the chimps with the hominids (Homo) - a central point in the present discussion?"  I'd call australopiths+Gorilla+Pan+Homo all "hominid", as opposed to "pongid" = orangutans + fossil relatives. The term "hominins" can better simply be replaced by Homo IMO. The mid-late-Miocene probably-hominids in Africa (Chorora-, Nakali-, Samburupithecus c 10 Ma) were remarkably large & +-gorilla-like, but with thick(er) enamel. Late-Miocene Sahelanthropus c 7 Ma also was more gorilla-like. Orrorin c 6 Ma was more Homo-Pan-like IMO. I'm not sure Ardipithecus was hominid, even sensu lato. You can read my recent view on ape+human evolution in "The aquatic ape evolves: common misconceptions and unproven assumptions about the so-called Aquatic Ape Hypothesis" Hum.Evol.28:237-266, 2013. In brief, I discern schematically 3 hypotheses:

1) Aquarboreal Hypothesis (Mio-Pliocene hominoids incl.australopiths): Miocene hominoids in hot swamp/mangrove forests c 20 Ma spent more & more time in the swamp below the branches, collecting floating herbs (papyrus, aquatic herbaceous vegetation AHV) & hard-shelled foods (palm nuts, mangrove oysters, hard-shelled invertebrates HIS), evolved vertical & below-branch climbing, a central & vertical spine, tail loss, a larger body, wider thorax & pelvis, stone tool use & thick enamel.

2) Littoral Dispersal Hypothesis (archaic Homo), an update of AAT senso stricto: early-Pleistocene Homo in forested & later more open coasts spent more & more time in littoral waters of Africa & Eurasia, beach-combed, waded & dived for shell- & crayfish, evolved shallow-diving skills (voluntary breathing), a projecting nose & mid-face, very heavy skeletons for ballast, flat low long skulls, larger brains (DHA), tool making & mouth-throat adaptations for swallowing soft & slippery sea- & other foods.

3) Wading Hypothesis (late-Pleistocene H.sapiens): Early H.sapiens spent more & more time wading in fresh water, collecting diverse plant & animal foods from very shallow aquatic & waterside habitats, evolved more gracile skeletons, very long & straight legs, stronger basi-cranial flexion, pronounced chins, flatter faces, high-vaulted skulls & more complex tools.

Anek, I just had a look at the discussion in Curr.Anthr., I sent the author this email:

I read with great interest your recent discussion in Current Anthropology 55:59-81:

'Is the "Savanna Hypothesis" a dead concept for explaining the emergence of the earliest hominins?'

From Dart's 1925 paper in Nature:

"... It will appear to many a remarkable fact that an ultra-simian and pre-human stock should be discovered, in the first place, at this extreme southern point in Africa, and, secondly, in Bechuanaland, for one does not associate with the present fringe of the Kalahari desert an environment favourable to higher primate life. It is generally believed by geologists (vide A.W.Rogers, "Post-Cretaceous Climates of South Africa," African Journal of Science, vol.xix, 1922) that the climate has fluctuated within exceedingly narrow limits in this country since Cretaceous times ..."

IOW,

- Dart found Taung in the 'veld', the "fringe of the Kalahari",

- geologists in 1925 thought the climate hadn't changed much since Taung, so Taung must have lived in the 'veld',

- Dart thought Taung was "pre-human": a human ancestor.

Leading primatologists in the 1920s said Dart had found some sort of fossil chimp, no human ancestor.

At was only a few decades later, when the Piltdown skull (large brain, large canines) was unmasked, that PAs followed Dart's diametrically opposite hypothesis:

that Taung (small brain, small canines) was about halfway between apes (small brain, large canines) & humans (large brain, small canines),

and also that our ancestors (i.e. Taung) therefore had lived in savanna-like conditions.

It seemed very logical (Darwin already):

quadrupedal simians live in forests, bipedal humans live on the ground,

IOW, when human ancestors left the forest for the savanna, they became human=bipedal.

This savanna hypothesis was based on unproven suppositions:

- Tim Partidge in 1980s showed that Taung had lived in "a more humid environment".

It now appears that all or nearly all australopiths lived in well-wooded & well-watered milieus (see refs in attachment).

- There's no evidence we descend from apes ("ultra-simian"), rather both humans and apes evolved (in different directions) from more australopith-like ancestors:

it's not ape>australopith>human, but it's australopith-like>chimp//gorilla & australopith-like>human.

- There's even no evidence that Taung was a human ancestor:

the humanlike features of australopiths (thick enamel, small canines, vertical spine etc.) could well be primitive-hominoid rather than human-derived, e.g. some or most Miocene apes already had thick enamel & small canines ('Ramapithecus') & vertical spines (Moroto).

The discussion in CA is often mostly about definitions of 'savanna', but this is unnecessary IMO: apparently the savanna idea (even in 'mosaic' form) is a fantasy, based on no real evidence.

Only professor White mentioned the IMO very relevant paper by Bender, Tobias & Bender.

I was surprised not to find in the discussion in CA a reference to professor Tobias' famous lecture in 1990s, where he said:

"All the former savannah supporters (including myself) must now swallow our earlier words."

http://users.ugent.be/~mvaneech/outthere.htm

I was also surprised not to find a reference to my letter to Nature in 1987, which was the basis for professor Tobias to question the savanna hypothesis:

'Origin of hominid bipedalism' Nature 325:305-6:

Sinclair et al.(1) believe that human bipedalism arose in scavenging hominid ancestors that had to carry their children while following migrating savanna ungulates, but this seems highly improbable. There was no empty niche of migrating scavengers to be occupied by hominid ancestors. Not only vultures, but also canid, felid and hyaenid carnivores were much better preadapted for such a niche. They possessed sharp beaks or long canine teeth and did not need to carry stones for cutting carcasses. ...

Another argument against the migrating hypothesis in particular and the savannah theory of human evolution in general is that it is highly unlikely that hominid ancestors ever lived in the savannas. Man is the opposite of a savanna inhabitant. Humans lack sun-reflecting fur (4), but have thermo-insulative subcutaneous fat layers, which are never seen in savanna mammals. We have a water- and sodium-wasting cooling system of abundant sweat glands, totally unfit for a dry environment (5). Our maximal urine concentration is much too low for a savanna-dwelling mammal (6). We need much more water than other primates, and have to drink more often than savanna inhabitants, yet we cannot drink large quantities at a time (7-8). ... It is difficult to understand why most anthropologists keep believing in the savanna theory (possibly because it goes back to Darwin), or why so many anthropologists keep trying to seek the most improbable reasons for bipedalism, while they should know there are much better explanations (9-11).

Renato & Nicole Bender co-authored a paper which can be found by googling 'Verhaegen econiche Homo', and which in much greater details disproves the savanna idea.

It also the disproves the now popular 'endurance running' ideas, a modern version of the savanna hypothesis (which remarkably was not mentioned in the discussion in CA).

For an IMO very (bio)logical view of ape & human evolution, based on fossil, paleo-environmental, comparative, anatomical, physiological etc.data, please see the attachment.

Marc- thanks for your very excellent elaborate replies and pdf copy of your paper in HE. It needs considerable time to read and digest your thoughts and more so to re-evaluate the same.

Without reading your paper fully, although it is premature for me to speculate, but may I just have an impression that for an acquaboreal hominid it was easier to travel a large distance along the sea coast compared to a terrestrial hominid/hominin?

Can we explain Homo habilis gracility by acquaboreal adaptation?

Aquarboreal (term of Marcel Williams) = aquatic + arboreal, from Latin aqua=water + arbor=tree.

Anek, you ask: "Was it easier for an aquarboreal hominid to travel a large distance along the sea coast compared to a terrestrial hominid/hominin?"

Dispersals seem indeed to be easier along waterways than overland.

Hominoid evolution shows several out-of-Africas, at least 3:

1) Early-Miocene (~20-18 Ma), some or all hominoids left Africa: hylobatids (gibbon-siamang) now live in SE.Asia, pongids (orang) idem. Probably hylobatids & pongids left Africa apart, since pongids are closer relatives of hominids (now Pan-Homo-Gorilla) than of gibbons. Some 18 Ma, hominids-pongids left Africa along the Tethys coasts, pongids went East (now Indian Ocean), hominids West (Mediterranean coastal forests). Whether all hominids left Africa, is still debated: European Gripho-, Pierola-, Dryo-, Ruda-, Hispano-, Ourano-, Oreo-pithecus etc might or might not closer relatives of (later) hominids. Probably-hominids in Africa were Chorora-, Nakali- & Samburu-pithecus ~10 Ma, then come Sahelanthropus ~7 Ma (Gorilla??) & Orrorin ~6 Ma (Homo-Pan??), after 5 Ma we have Ardipithecus (presumably) & after 4 Ma the australopiths (IMO relatives of Gorilla or Pan). About 5 or 4 Ma, Homo & Pan split (possibly in the littoral forest along the Indian Ocean), Pan remained in Africa, and Homo colonised the Indian Ocean coastal forests IMO:

2) Pliocene human ancestors, according to retroviral data (Yohn cs 2005 PLoS), were absent from Africa at least between 4 & 3 Ma, I guess they lived then in the Indian Ocean coastal forests of S.Asia. When the Pleistocene sea-levels dropped, vast tree-poor & shellfish-rich areas came available for handy, intelligent, stone-using "littoral apes", who gradually also learnt to dive deeper for shellfish (= AAT sensu stricto IMO). With interglacial high sea-levels, e.g. ~1.8 Ma, Homo populations appeared in lake Turkana together with stingrays, no doubt via sea-connections, but at that time we also find Homo fossils amid barnacles & shells in Mojokerto, tools in a coastal palin in Algeria (Aïn-Hanech & el-Kherba), at a paleo-lake in Iran & in large rivers near the Black-Caspian Sea connection then (Dmanisi). They certainly hadn't gone there running over savannas... A remarkably fast worldwide dispersal is also seen e.g. in the pakicetids (~45 Ma IIRC) when they developed pachyosteosclerosis as in H.erectus: extremely thick, dense, brittle, calcium-rich bones for hydrostatic ballast in shallow littoral waters.

3) Late-Pleistocene ~70 ka, non-African humans left Africa for the 3d time (out-of-Africa sensu stricto).

IOW, Miocene hominoid & Plio-Pleistocene Homo migrations typically occurred along the coasts.

You also ask: "Can we explain Homo habilis gracility by aquarboreal adaptation?"

Aquarboreal means tree+water. For climbing trees, you need lightly-built bones. Most aquarboreals might be surface-feeders (e.g. A.boisei is often found amid sedges in papyrus swamps, and their dentition, micro-wear, C & N isotopes, paleo-environment etc suggest A.boisei fed largely or partly on papyrus sedges, see the work of P-F.Puech, N.vd.Merwe, Sponheimer etc., comparable to lowland gorillas wading in forest bais for sedges, google "gorilla bai" illustrations). For diving, you initially (shallow & slow diving, large lungs) need heavy bones, as seen in erectus-like archaic Homo (neandertals were about halfway erectus & sapiens in this respect). H.sapiens' gracilisation is partly a post-aquatic adapation (not diving any more). Gracilisation in "habilis" (possibly depending on which fossils you mean) can be (re)adatation to an aquarboreal lifestyle, or to a more arboreal life, or to a fresh water side life (sea water is ~2.5 % denser than fresh water, so shallow littoral divers typically show pachy-osteo-sclerosis).

Anek, you definitely have to read my recent papers.

Very interesting answer Marc, thank you

Just a point of detail in a line of argument I mostly agree with - in point 2 you suggest that  human ancestors were absent from Africa during the Pliocene 3-4 Ma and I am wondering if that is necessarily the case since the same pattern of retrovirus infection amongst Pan-Homo- Gorilla would be seen if those species were in roughly the same region but simply separated for a period by physical or other barriers?

Such a situation currently exists between Pan troglodytes and Pan paniscus for example and so it is not too hard to imagine our own species being included in a similar process

Our ancestors remaining in the same region during this time also sits a lot easier with data showing that the Pubic louse Pthirus pubis crossed over from Gorillas about 3 Ma (e.g. Weiss (2009) Apes, lice and prehistory Journal of Biology 2009, 8:20 ).

Marc,

In your Aquarboreal ancestors? paper you state "This coastal phase could help

explain furlessness, subcutaneous fat and voluntary breath-control – features that are unique among primates but common to walruses, seacows, babirusas, hippos,

whales and dolphins [4,5]." My understanding is that breath control has been demonstrated in the orangutan where at least one individual has learned to whistle and this is an ability that requires breath control.

John, besides whistling, is there any other related specialty of the Orangutan as it is also called as a "Talking Ape" ?

Colin- another interesting point from Marc's paper surfaces in No.2) "Pliocene human ancestors, according to retroviral data (Yohn cs 2005 PLoS), were absent from Africa at least between 4 & 3 Ma, I guess they lived then in the Indian Ocean coastal forests of S.Asia."

If it was so, then some of the Homo erectus populations continued to inhabit southern Indian coast even before they spread to Africa. This may be supported by the new dates of of over 1.4 ma assigned to the Attarampaccam (Tamil Nadu) Palaeolithic industry by Pappu et al. (in Science 2010).

Anek,

I'm afraid I do not have any information on related abilities at this time. The comment about the breathing illustrates the problematic nature of 'explaining' specializations by creating an imagined selection scenario. A comparable example is all the varied and bizarre notions that have been generated to 'explain' concealed ovulation evolving in humans while 'forgetting' that orangutans also have concealed ovulation (i.e. absence of estrus swelling during ovulation). And of course if humans and orangutans are sister taxa then they each have concealed ovulation because this features was inherited from the last common ancestor that was not also the ancestor of African apes.

John- the concealed ovulation in Orangutan and humans considered by you a shared trait from their last common ancestor not shared  by African ape is very important. If is is not convergent trait then it would over throw the human-African ape theory.

I  think Marc would be able to explain through AB adaptation or other notable champions of he 'African-ape-human' theory may have other alternative interpretation for the same.

Humans and Orangutans also share some more unique traits lacking in African apes- like long coarse and sparse body hair, reduced number of lumbar vertebrae..... you have long list. This would further create difficulties for the unique  'African ape-hominid' theory until there is strong fossil evidence to unite them together.

John, you say: "In your Aquarboreal ancestors? paper you state "This coastal phase could help

explain furlessness, subcutaneous fat and voluntary breath-control – features that are unique among primates but common to walruses, seacows, babirusas, hippos, whales and dolphins [4,5]." My understanding is that breath control has been demonstrated in the orangutan where at least one individual has learned to whistle and this is an ability that requires breath control."

Yes, orangutans (& possibly also the other great apes, Gorilla & Pan) seem to be intermediate in this respect. This is not unexpected, e.g. because they underwent apparently an aquarboreal phase (see the paper you mention & more recent papers of ours on this subject). Some orangs are able to swim a few meters underwater (recent paper by Bender IIRC). I'd perhaps better written "This coastal phase could help explain fur loss, SC fat &  profound breath-control" or so. In any case, humans are not only better divers than orangs, but also better singers. Thanks for your correction. Could you please send me [email protected] the paper with the information on the whistling orang?

Anek- That Homo & Pongo have some features in common that are not seen Pan, Gorilla & hylobatids (e.g. concealed ovulation?) could be due to parallel loss in Pan & Gorilla, or to parallel evolution in Homo & Pongo, but does not change the DNA data that our closest relative is Pan, then Gorilla, then Pongo, then hylobatids, etc.

Colin, yes, that our direct ancestors (i.e. not necessarily all Homo then) were not in Africa between 4 & 3 Ma (Yohn cs 2005 PLoS) is by no means settled, but that we got Pthirus from gorillas is even less certain IMO: I'm inclined to think that Homo kept both lice from the hominid LCA, that Pan lost Pthirus, and Gorilla lost Pediculus, and that Pthirus evolved slower than Pediculus.

Marc - the story is of course complicated (involving according to Reed et al 2007 at least one duplication, two losses, and one host switch) and whilst these authors agree with the 'Pair of Lice lost' hypothesis with respect to Pthirus and Pediculus they are nonetheless convinced on the basis of their data showing that Pthirus pubis and Pthirus gorillae diverged only 3-4 Ma that there must have been a host switch. If that is the case it follows that we must have been in Africa at the time

Hence I would be very interested to read the evidence you have that leads you to a different conclusion if you can let me have the references?

I would also be grateful if you could please pass on the whistling Orangutan paper if you get a copy as that sounds very interesting

Thanks

----------------------------------

Reed DL, Light JE, Allen JM, Kirchman JJ: Pair of lice lost or parasites regained: the evolutionary history of anthropoid primate lice.

BMC Biol 2007, 5:7 

http://www.biomedcentral.com/1741-7007/5/7

Marc,

Your assertion that "That Homo & Pongo have some features in common that are not seen Pan, Gorilla & hylobatids (e.g. concealed ovulation?) could be due to parallel loss in Pan & Gorilla, or to parallel evolution in Homo & Pongo" is theoretically possible, but only if humans and orangutans were not sister taxa.

If by "but does not change the DNA data that our closest relative is Pan, then Gorilla, then Pongo, then hylobatids, etc. "  you are claiming that this DNA data cannot be challenged by any other DNA data then I would disagree. The shared derived morphological similarities between humans and orangutans are DNA based (or they would not be inherited consistently). Further, they are more 'genetic' in terms of inheritance as they involve developmental genetic processes where as the molecular DNA comparisons are just comparisons of DNA sequence morphology for which there are several possibilities as to why they may in some cases give erroneous results.

I am not aware of published material on the orangutan whistling, but there is a video on the web. I have not looked at that for a long time so I would have to check to see if that is still available.

Colin-  If we simply assume that Pthirus evolved a bit more slowly than Pediculus (cf the early probably-hominids Nakali-Chorori-Samburupith fossils c 10 Ma seem to have resembled (except for their thicker enamel) Gorilla more than Homo-Pan), we don't have to accept that we got Pthirus from gorillas by eating them or having sex with them. There are other considerations: AFAIK African apes are born furless but with scalp hair (AH Schultz, SC Coon) & redevelop fur (only upper fur) after birth, so the hominid LCA (HPG) might have had 2 lice: scalp & pubic (i.e. "allopatric"), and when HP & G split, G redeveloped body hair, both lice came in contact, and G's pubic louse replaced Pediculus, whereas in chimps, after the H & P split, P redeveloped fur, and the scalp louse replaced Pthirus. I have no idea whether it happened like that, I only consider it a possibility (cf aquarboreal theory): we always underestimate the frequency of parallel evolution, but it's the cornerstone of Darwinism. So: no need to hypothesize host switches. Whatever, in any case, the lice don't prove our ancestors 4-3 Ma didn't leave Africa (Yohn cs 2005 PLoS).

John-  Of course, as expected, Homo & Pongo have a few features in common that are not seen in P of G, but werever DNA & morphology are seemingly in contradiction in the eyes of some (not in my eyes here), the DNA data are correct: morphological parallelism is very frequent in evolution (it proves Darwin's theory), e.g. it's now generally accepted (as I argued already 20 years ago) that chimps & gorillas evolved knuckle-walking in parallel. Another example: in the 1970s it was believed that gorillas & chimps were closer relatives of each other than one of them was to Homo, and that the man/ape split happened >10 Ma, but the DNA data (Sarich, Goodman etc.) proved this wrong.

Here's a press release on the orangutan whistling.

http://www.sciencedaily.com/releases/2008/12/081211112004.htm

Marc,

Agreed that most believe that where DNA sequences are in-congruent with morphology it is because the morphology is wrong. This belief has no empirical substantiation. It is, in my view, voodoo evolution. Ironically, the view that DNA sequences shows morphology to be wrong about human - ape relationships  means that the fossil record of hominids and apes is completely devoid of evolutionary meaning since it has already been decided that morphology cannot be relied upon, and yet people make up two contradictory rules - that morphology is useless for living relationships but authoritative for fossils or fossil-living relationships.

I read the whistling news of the Orangutan which marks development of a higher human -like faculty in it. Coupled with the concealed ovulation, sexual behavior and considerable other advance learning skills, the Orangutan draws closer to hominins.

The morphology also supports the same, but it is 1% more DNA difference from humans vis-a-vis the chimp which has been highlighted to show Orangutan's remote ancestry with humans compared to the African apes. Why cannot we interpret the 1% more divergence due to a shift from its ancestral ecology of the Orangutan?

At large, both Asian and African great apes have 97% DNA similarities with humans and that in my view is plesiomorphic retention from their common ancestor. I speculate that the apes are derived to different extents from this basic ancestral genomic make up; the Orangutan seems slightly more derived followed by the Gorilla, whereas the Pan is less derived and retained the primitive make up like the hominins. If we accept this interpretation then there is no conflict between morphology and genetics- and there is is no need to reject one to prefer the other.

Anek,

The problem here is that there is conflicting information about the distribution of shared derived characters. The cladistic premise is that a larger set of shared derived characterss (or character states) provides for a smaller number of ad hoc hypotheses to explain their origin if that set is seen as representing the phylogenetic sequence. In many cases there is considerable ambiguity in the distribution of similarities among taxa and what stands out with humans and orangutans is not that they share more such features in common, but that they share so many. In addition to the 28 or so that seem to be very or fairly strongly corroborated there are more than have yet to be researched in detail and others that are consistent with the orangutan relationship even if they may not be uniquely shared (as with concealed ovulation). My personal opinion is that in this case it is the molecular result that is more problematic. But that's just my opinion and there is as yet no recipe for making an 'objective' decision.

It will be very interesting in the future to find out whether chimps or gorillas can whistle.

John & Anek - whistling orang - very interesting - thanks a lot for the link.

Chimps (& probably orangs?) can voluntarily make mouth smacking sounds. Chimps & orangs can form a round mouth opening + protruding lips to suck fruits (better than gorillas), which they do voluntarily: can sounds (e.g. whistle?) be a byproduct of such suction? Some arboreal animals (often?always monogamous? parrot etc.) can very well imitate human & other sounds. Cetacea can voluntary breathe (for diving), and some (humpback) can "sing" underwater. Some seals can voluntarily imitate human speech. So it's not clear to me whether whistling orangs can be explained by their arboreal ancestry (cf duetting hylobatids), their suction feeding abilites (fruits, grubs, molluscs...), their limited diving skills (ex-aquarboreal), or combinations of these (I guess the 2d).

Human speech is based on bringing the emotional/territorial loud & variable sounds (cf gibbon song) under voluntary breathing (cf diving mammals), plus transforming these sounds in the mouth: humans (& chimps & orangs? only at the lips?) can close our mouth at the lips, teeth, palate, uvula etc. (cf labial, dental, palatal, uvular consonants) for better swallowing soft & slippery foods without biting or chewing: fruit juice, snails, shellfish... The combination of all this (+ larger brains? cf DHA in aquatic foods? cf Pleistocene Homo's littoral dispersal) was the basis for human speech IMO, see our speech papers, e.g.2004 with Stephen Munro "Possible preadaptations to speech – a preliminary comparative approach" Hum.Evol.19:53-70,

2011 M.Vaneechoutte, S. Munro & M.Verhaegen "Seafood, diving, song and speech" in M.Vaneechoutte cs eds 2011 "Was Man More Aquatic in the Past? Fifty Years after Alister Hardy: Waterside Hypotheses of Human Evolution" eBook Bentham Sci Publ :181-9.

John & Marc- While John has shown concern for the problematic molecular affinities uniting the Af apes-hominids, Marc has cited so many parallels for whistling/songs/speech among non related taxa. Both demonstrate dilution of the characters considered important in resolving the phylogenetic debate. With this, we are coming to a chaotic situation in which we cannot take African or Asian side in deciding the ape-human common ancestry based on extant molecular or morphological including behavioral shared affinities. Perhaps the Creationists would better exploit this situation to dump evolution!!

Ironically, Creationists were quick to recognize the morphological similarities between humans and orangutans and used this as a 'disproof' of evolution! One can still sometimes find references to this on the web.

So, they have already done it!! I think it needs a full conference of all kinds of scientists interested in the debate on common ancestry. One important attempt was in 1980s which generated the edited volume of "New Interpretations of the Ape and Human Ancestry.?

Great suggestion about the conference, but it will never happen (sticking my neck out here). If I recall correctly, the new interpretations book did not address this issue of orangutan origins to any extent. There was a compilation of papers in an edited book about the orangutan theory in 1988, but now I think that ideas on the molecular evidence have fossilized to the extent of absolute truth. Some practitioners will even refuse to edit papers on the subject. The editors had some difficulty even finding reviewers for our 2009 paper. Among the paleontologists opposition is nearly absolute. Even orangutan conservation folk don't like the idea. One person working for an orangutan conservation agency told me that he would lose his job in orangutan conservation if he expressed sympathy to the possibility of orangutan origins.

Anek-  "New Interpretations of the Ape and Human Ancestry" was mostly about the re-interpretation of "Ramapithecus". Many PAs in the 1970s believed "Ramapith" (in fact a female Sivapitheucs with small canines) were our (Homo's) ancestors, but it became clear in the 1980s that "Ramapith" had nothing to do with African hominoids, but was probably pongid. Time & time again we see the same mistakes in PA (paleo-anthropology), e.g. most PAs think australopiths were our ancestors, but all human-like traits they see in australopiths are primitive, not derived: thick enamel, smaller canines, vertical spine, "low" iliac blades etc.

Marc,

I agree that Ramapithecus/Sivapithecus is apparently closer to orangutans than honinids, but that does not mean that it had nothing to do with African hominids. I would be interested in what you cite as evidence (other than incongruence with molecular phylogeny) that thick (molar) enamel is primitive. Also, the characters we cite for australopiths being related to Homo are as follows and I would be interested in any refutation you would offer (numbers refer to ref numbers in our publication).

9 pubic ramus long, 10 ilium superoinferiorly short, 11 ilium expanded posteriorly, 12 iliac crest (tubercle) thickened, 13 anterior inferior iliac spine, knoblike, 14 anterior inferior iliac spine near acetabulum, 15 linea aspera present, 16 spiral line connects to linea aspera, 17 femur condyles unequal, 18 femoral neck thickened inferiorly, 19 femoral shaft outwardly angled, 20 two tibial tubercles, 21 lateral tibial facet concave, 22 lateral prox. tibial facet level with medial facet, 23 distinct angle at L5-S1.

John & Marc- I am sorry to observe that even if John raise the Orangutan -hominid list to a century mark, the Orangutan has to remain a distant relative of the hominids since PAs have clear continental biases. Most even would not entertain any idea which misadventures to seek hominid origins outside African continent. For them Asia remains Orangutan's paradise and has nothing to do with hominins. On the same belief or bias all diverse taxa and species of the ramapithecines /sivapithecines or the like hominoids, whether or not  they really qualify for Orangutan's ancestry, are supposed to be relegated to the "pongid evolutionary waste basket". Similarly, even if hominins existed in Asia, they have to be all a paraphyletic side branch!!!

But, how does it matter so much if hominids have not originated in Asia and if Africa becomes the  "cradle". We need to be more concerned with the processes of hominid origins rather than any continent. We are to explain the apparent paradox between morphological and molecular affinities without taking sides like political parties but as neutral scientists. We need to re-think and re-understand the character polarities before assigning them phyletic weight. Both of you have discussed at a good length, I complement both of you for a healthy discussion.

John-  Most early great hominoids had thick enamel (some had thinner, some had superthick), so thick enamel is probably ancestral: Pongo & Homo kept thick enamel, Pan got intermediate, Gorilla got thin enamel.

Of course, Homo is related to apiths. In some instances (thick enamel, low ilia, vertical spine etc.), Homo is more primitive than Pan & Gorilla, in others Homo is derived (brain size, external nose, very long legs etc.), and still others, Pan and/or Gorilla are primitive (small brain, derived (longer arms-hands in Pan, knuckle-walking & long ilia in Pan // Gorilla, thin enamel in Gorilla, etc.). I've discussed this in my Hum.Evol.papers, in detail in my 1990s papers, for a summary & overview of Afr.ape-human evolution see my 2013 paper, see www.researchgate.net/profile/Marc_Verhaegen, independent.academia.edu/marcverhaegen (or let me know your email address). There's no problem with the DNA data. The preassumption many PAs make is that we had apelike ancestors (schematically they think ape>apith>us), but the living apes are derived, they're not primitive, they live today, a few millions of years after the apiths: apiths are more primitive than extant Pan, Homo & Gorilla, who are derived in different directions (often Pan // Gorilla). So the evolution is not "ape">apith(like)>Homo, but apith(like)>Homo plus apith(like)>Pan plus apith(like)>Gorilla. We don't descend from chimps: both Homo & Pan had the same apith-like ancestor c 5 Ma, who probably looked +-like A.africanus & perhaps bonobos: "small" brain, thick enamel, rel.small canines, basi-cranial flexion, rel.inferior foramen magnum, no external nose, "low" ilia as in monkeys & Homo, no knuckle-walking, arm length +-as in Homo & Gorilla, leg length +-as in Pan, feet as in Laetoli (female lowland gorilla, newborn chimp), vertical spine as in hylobatids & Homo, very broad body (pelvis, thorax, skull), broader than in all living primates, iliac flaring, long femoral necks, very valgus knees etc.

This evolution of Gorilla-Homo-Pan has nothing to do with Pongo, who diverged from our ancestors c 15 Ma, but evolved several features in parallel with (or in excess of) the African apes (very long fingers, arms & ilia, very short 1st digital rays, arm-hanging & below-branch locomotion etc.) and was more primitive in others (e.g. thick enamel). As Anek says, it's often a problem of character polarity.

Marc,

Which hominoids do you cite as having thick enamel to substantiate your assertion that the common ancestor of hominoids?

Thank you for clarifying that you are in agreement with Homo and australopiths being closely related. I had got the erroneous impression to the contrary from your earlier comments.

Regardless of what one might think about how ape like our ancestors were, the evidence currently points to australopiths being closer to us than any of the living apes. I guess I get lost as to what you consider evidence for humans and Pan having a common ancestor c 5 Ma and that this looked like A africanus. So please send me the relevant publication at [email protected]

What do you cite as evidence that the Pongo lineage diverged from our ancestors c 15 Ma?

Marc- though you are to reply to John, I got from your arguments that hominid thick enamel and associated dental and other traits are primitive and retained in the Orangutan but lost in Af apes. It sounds logical.

But, like John, I also want to understand from which African  fossil ancestor they were inherited by the austropiths and why not by the chimp and gorilla? In my earlier statements I have attached great significance to such "primitive" hominids traits since they enhanced dietary regime, diversity and therefore  success of the hominins. I see no logic for their being lost in the chimp-gorilla lineage as the loss would delimit there ecological domain. I would rather interpret that the thin enamel of the chimp-gorilla lineage has been inherited from a similar 'thin-enameled'  African /Eurasian/European hominoid ancestor, like Dryopithecus sp.  I will solicit your opinion or explanation p.

For added clarification of the dental enamel thickness, I am only referring to the molar enamel. Among living primates thick dental enamel is unique to humans and orangutans, and to a few species in two monkey genera (one OW and one NW). Therefore, in looking at relationships among large bodied hominoids (humans and great apes), the occurrence of thick molar enamel in humans and orangutans supports their having a closer relationship with each other than either has with the African apes - IF the relatively isolated occurrence of thick enamel in OW and NW monkeys is regarded as an separate development (i.e. these monkeys are well supported as belonging to monkeys rather than a clade of humans, orangutans, and two monkey genera. 

With this starting point the question for fossils is whether fossil large bodied hominoids with think molar enamel also belong to, or are sister taxa to a human-orangutan clade. Jeff and I have suggested that taxa such as the australopiths, Orrorin, Ouranopithecus, Ankarapithecus, Sivapithecus, Leufengpithecus, Khoratpithecus are closely related to the human-orangutan clade or are members of that clade. Other fossil taxa may also be associated with this grouping or it is possible that thick molar enamel may prove to occur in fossil apes that are more closely related to African apes. Some fossils known from dental remains have been regarded as similar to gorilla in overall dimensions, but their thick enamel may suggest that their relationships are not  close to gorilla. More material will be needed for these to make a confident determination.

Thanks John for your reply. I also look at this broader orang-hominid clade. But, let me wait for Marc's reaction to your and my earlier query, and now to your this one too..

John, you ask: "Which hominoids do you cite as having thick enamel to substantiate your assertion that the common ancestor of hominoids?"

Most Miocene hominoids: Afro-Moroto-Helio-Gripho-Pierola-Anola-Ourano-Nachola-Chorora-Samburo-Siva-Lufeng-Giganto-etc.pithecus, refs in my 2013 paper I attached. There were more (super)thick-enameled hominoids in the past than thin-enameled.

"Thank you for clarifying that you are in agreement with Homo and australopiths being closely related. I had got the erroneous impression to the contrary from your earlier comments.

Regardless of what one might think about how ape like our ancestors were, the evidence currently points to australopiths being closer to us than any of the living apes. I guess I get lost as to what you consider evidence for humans and Pan having a common ancestor c 5 Ma and that this looked like A africanus. So please send me the relevant publication at [email protected]"

You can find my Hum.Evol.papers by googling "verhaegen human evolution". Note I did not say that Homo & australopiths are more closely related than Pan & australopiths, and the objective evidence does not point to australopiths being closer to Homo than to Gorilla or even Pan, see my Hum.Evol.papers. As Anek says, it's often a matter of character polarity.

"What do you cite as evidence that the Pongo lineage diverged from our ancestors c 15 Ma?"

Hominids & pongids split when the African-Arabian plate hit Eurasia, and soon thereafter hominids went West (peri-Medit.Sea) & pongids East (S.Asia). This fits the DNA data that Homo & Pongo or Pan & Pongo are about 3 times more different than Homo & Pan, and 2 times Homo & Gorilla.

Anek-  Why gorillas evolved rel.thin enamel is uncertain. Enamel thickness appears & disappears frequently in evolution. Gorilla's thin enamel (sharper ridges, e.g. to slice herbs) seems to be an adaptation to more terrestrial herbaceous vegetation (THV), whereas their ancestors ate more aquatic herbaceous vegetation (AHV). Chimps (less herbivorous) have intermediate enamel. Humans & orangs kept the thick enamel (more omni- or (hard?)frugivory). Wetland hominoids seem to have had (super)thick enamel (e.g. poor quality of sedges etc.? small snails on AHV?), but the Pleistocene coolings & dryings apparently favored a more terrestrial life cf parallel evolution of knuckle-walking in Pan // Gorilla. Most monkeys (herbivorous) have rel.thin enamel, but e.g. the omnivorous capuchins have rel.thick enamel (hard-object-feeding? nuts? hard-shelled invertebrates? mangrove oysters?). In many instances (e.g. enamel thickness), Pan & Gorilla are apparently more derived (e.g. drier forests? ground-dwelling?) than Pongo or Homo.

Marc-you are giving good ecological explanations for the the occurrences of the thin or thick molar enamel, which, of course can be explained through ecology.  That is fine, but the fundamental question remains whether the enamel thickness could be used to infer common ancestry or not? if not, then other morphological similarities, which can also be explained /accountable to locomotion, etc., may also be dismissed or become little relevant in understanding phylogeny.

Then, perhaps what we are to depend upon the DNA data for phylogeny. But, that again is based on the extant DNA similarities or dissimilarity.  Who knows about the ancient DNA affinities of the Australopithecus and African apes?

Enamel thickness, as +-all body characters, can be used to reconstruct evolutionary relationships (esp.of fossils, where no DNA is available). The finer the distinctions (very thin, thin, intermediate, thick, superthick), the better. But there's always the possibility of reverse evolution: some thick-enameled spp had thin-enameled ancestors, and v.v. We have DNA from neandertals & denovians, but not from australopiths.

At the risk of being an Agent Provocateur I have asked a new question.

https://www.researchgate.net/post/Why_is_paleoanthropology_the_most_contentious_of_sciences

If PA is the most contentious of all sciences, it's because of anthropocentrism IMO, which also seems to be the main reason why so many traditional assumptions in PA are wrong, e.g.

1) Many PAs think that australopithecines are closer relatives of Homo than of Pan or Gorilla, because they were "bipedal", but comparative, embryological & other data suggest that Pan & Gorilla also had more bipedal ancestors (discussed in attachment).

2) Many PAs believe that our Pleistocene ancestors were "endurance runners", but this is physiologically, nutritionally & otherwise impossible, e.g. the human olfactory bulb is only 45 % of the chimp's, whereas if we went from forest to plain we had evolved a keener olfaction. Moreover, salt & water (sweat) are scarce in savannas, as are most or all brain-specific nutrients: iodine, DHA, taurine, oligo-elements. Etc.