The prehistory of pedestrians

[trehinp]

La Préhistoire du piéton
Essai sur les nouvelles origines de l'Homme
par Yvette Deloison
PLON, Paris avril 2004

Free translation :
"The prehistory of pedestrians
Essay on the new origins of human beings"

This book is a rather technical essay about bipeds, their apparition and what distinguishes bipeds human from other bipeds primates.
The author, "Chargé de Recherche au C.N.R.S., Docteur d’Etat ès Sciences. Membre de l’équipe U.P.R. 2147<NOBR> </NOBR>: "<NOBR> </NOBR>Dynamique de l’Evolution humaine : Individus, Populations, Espèces<NOBR> </NOBR>". develops a radically different thesis from that currently accepted for human apparition on Earth.
 
Here is a short article on this subject :

<< The Japan Times, April 6, 1999
By VILEM BISCHOF
http://www.trussel.com/prehist/news114.htm
First upright apes may have walked in 15 million B.C.
 
PARIS (AFP-Jiji) A primitive ape walked upright as long as 15 million years ago, French paleontologist Yvette Deloison estimates.
Deloison, with France's National Center for Scientific Research, said last week that certain species of apes later abandoned the bid to stand upright, while our ancestors became permanently bipedal.
The theory is considered groundbreaking, and could disprove the theory that "Lucy," a 3.2 million year-old Australopithecus discovered in 1974 in Ethiopia, is one of humanity's oldest ancestors.
"Lucy," said Deloison, "has bipedal characteristics, ... but she also has divergent big toes like those used by the big primates of today to climb trees."
"Evolution never goes backward," she said. "The human foot, highly specialized for bipedal use, cannot have been derived from a foot adapted to climbing trees, which is also highly specialized but different.
"Lucy thus cannot be the ancestor of humanity and, in consequence, to find the origins of biped creatures one has to look to much older four-footed primates that finally stood upright."
Deloison said she believed there were three species of two-footed primates. The first developed into hominids, the second became Australopithecines and the third developed into orangutans, gorillas and chimpanzees.
Her theory is backed by recent discoveries.
Australopithecus anamensis, discovered in 1995 in Kenya, was bipedal 4 million years ago. And in December, scientists in South Africa discovered an Australopithecus skeleton at the fossil-rich Sterkfontein caves.
Ron Clarke, who headed the excavations, said, "The anatomy of the ankle joint shows (it) was already bipedal but able to climb in trees by virtue of a divergent big toe."
Deloison said the front of the foot of the South African Australopithecus was designed for tree-climbing, while the back and the top were more bipedal.
"This fossil is about the same age as Lucy, or a little older, around 3.3 million years old. So now we have a 4-million-year-old Australopithecus that was perfectly two-footed, and two more recent skeletons that are less bipedal," she said.
Le livre contient une quantité impressionnante de détails sur la morphologie comparée des membres inférieurs humains et de ceux des grands primates. Apparemment d'autres auteurs ont également contesté la thèse traditionnelle de l'apparition de la bipédie.>>

Apparently Dr. Deloison is not the first to contest the validity of the lineage of "Lucy" for humans. But she seems to be pushing this argument further than any other researchers in this field.

For those of you who read French this is an interesting book.
 
Paul

[Daryl Habel]

Hi Paul,

For those who read English, I'll add that the Japanese news report was pretty interesting also.  I'm really happy to see that Dr. Deloison "believes there were three species of two-footed primates".  My question: only three?  I would have thought more than three species of "two-footed primates" existed.

However, given that she undoubtedly means three Miocene species that led to three descendant lineages, I'd like to ask you if she identifies any of these three Miocene primates by name in her book?  

As far as her theory being "backed by recent discoveries", citing A. anamensis and the South African "Little Foot" skeleton, I am  reasonably positive that  these "recent discoveries" can have other interpretations that also "back" other theories.  I'm particularly unimpressed by her argument that  Lucy's foot cannot be ancestral to later bipedal human, and everything following  "evolution cannot go backwards" (whatever that might mean) in the news story.

In other words, although I can respect Dr. Deloison's theory as possible,  it sounds like there is a lot of hype here, and not very much "new" substance to the argument.

IMO, of course.  Thanks for the note.

Dar

[trehinp]

I'd like to ask you if she identifies any of these three Miocene primates by name in her book?  

Hi Dar,

The book is not very specific on that aspect. Her main point being that rather than human being decending from a common ancestor walking on its four members, it is the reverse, a bipedalist creature, dating about 25 million ears ago, branched out in three  types or primates, 1/ the Humans, which remained entirely bipedalists, 2/ highly specialised monkeys living in trees, 3/  Australopitecines and other less specialised apes capable of both living in trees and bipedalism.

The aspect I found interesting in her book was more the refutation of classical theories of evolution applied to human beings than the hypothesis that she made about a common bipedalist ancestor.

One thing that may be of interest is that we may have to look farther down in time to find the "common ancestor" to apes and humans.

This relates to the post I wrote about birds who learn their songs which possess the same FoxP2 gene as Human beings while other primates don't have that gene... This too call for an older branching out of humans and apes than previously thought.

But I'm no specialist of genetics nor of bipedalism...

Any other ideas on the subject ?

Yours very friendly.

Paul

[Daryl Habel]

Hi Dar,

The book is not very specific on that aspect. Her main point being that rather than human being decending from a common ancestor walking on its four members, it is the reverse, a bipedalist creature, dating about 25 million ears ago, branched out in three  types or primates, 1/ the Humans, which remained entirely bipedalists, 2/ highly specialised monkeys living in trees, 3/  Australopitecines and other less specialised apes capable of both living in trees and bipedalism.

The aspect I found interesting in her book was more the refutation of classical theories of evolution applied to human beings than the hypothesis that she made about a common bipedalist ancestor.

One thing that may be of interest is that we may have to look farther down in time to find the "common ancestor" to apes and humans.

This relates to the post I wrote about birds who learn their songs which possess the same FoxP2 gene as Human beings while other primates don't have that gene... This too call for an older branching out of humans and apes than previously thought.

But I'm no specialist of genetics nor of bipedalism...

Any other ideas on the subject ?

Yours very friendly.

Paul

Paul,

Thanks for the explanation.  Even though Deloison does not specifically name the Miocene bipedal primates, the description you have provided makes it much clearer in my mind what her theory is all about (I can supply my own species conjectures).

I must say this "refutation of classical theories" is a bit too radical for my taste.  But I do agree with Deloison that the last common ancestor of apes and humans could very well have had bipedal tendencies (rather than a knuckle-walker like chimp and gorrilla, which is, seemingly, the presently most-favored hypothesis).

I do not agree that we have to look back 25 million years to find this last common ancestor (LCA).  In fact, the morphology of the LCA could very well have been similar to a Miocene (9.7 million-year-old) Dryopithecus laietanus, which is represented by a partial skeleton found in Spain (Moya-Sola & Kohler 1996).  I'm not saying D. laietanus was the LCA, just that the morphology existed from which the chimp/gorrilla/human LCA could have evolved from.

As far as your FoxP2 gene speculation (that the LCA has to be more ancient), I don't think you've got a leg to stand on there (sorry, bad pun).  Sure, humans and birds have the FoxP2 gene.  This only means it either was shared by the bird/human LCA  (Mesozoic - "Jurassic Park" time), or else it evolved as a parallel adaptation separately in humans and birds.

I think other primates DO have the FoxP2 gene.  I think the difference that made the news is that in other primates, it does not "turn on" for speech, like it does in birds and humans (IIRC).

Anyway, it is not the fact that birds and humans have this specific gene that is the important part of it's significance.  It's significance is that in both birds and humans, something in this gene "turns on" when humans use speech or birds chirp.

This FoxP2  "turn-on" again may be a common LCA trait (do lizards chirp?) or may be parallel evolution.  But either way, it is no reason to make one go searching for an earlier ape/human LCA.

Cheers,
Dar
(who wishes he could go enjoy Paris in the springtime!! Been 50 years absent for me.)

 

[trehinp]

I think other primates DO have the FoxP2 gene.  

Cheers,
Dar
(who wishes he could go enjoy Paris in the springtime!! Been 50 years absent for me.)

I'll answer this on the "Birds and Human learning language genes" thread.

Please come and visit. Where I live there are a few interesting sites:
 "Grotte du Valonnet" 1 million years BP
 "Terra Amata",  400,000 years BP
 "Grotte du Lazaret" 150,000  years BP
 "La Valée des Merveilles" 4,000 years BP
and a few other smaller sites...

Yours very friendly.

Paul

[lagarvelho]

Paul:

You must live somewhere in SW France.  Personally, I'd love to visit some of these places.
Anne g

[trehinp]

Paul:

You must live somewhere in SW France.  Personally, I'd love to visit some of these places.
Anne g

Indeed, Anne,

I live in Cagnes sur Mer, between Nice and Cannes.

You're welcome o visit. Let me know in advance as I do travel a lot...

Sincerely yours.

Paul

[trehinp]

Thanks Jacques,

For having posted in the BOOKYARD section the information on "COMPTES-RENDUS PALEVOL: special issue on the 'First Hominids'.
I went to the site you mention. It is indeed very rich in information."

It is interesting to note that, from the abstracts contents (these are the only free available info articles are for a fee) I didn't see a single reference to Yvette Deloison research on a different origin of bipedalism. Remember I mentioned her book in the "Human Evolutionary Biology" discussion, June 07, 2004.

<<La Préhistoire du piéton, Essai sur les nouvelles origines de l'Homme, par Yvette Deloison >>

Her work is not even criticised... But may be it is in the full articles...

It is interesting to see how difficult it is to get the attention of learned specialists, even as an other learned specialists as is Yvette Deloison who is a member of the French National Research institute (CNRS)...

It seems that it is difficult to go against a well installed paradigm, even just to test a new idea.

Paul

[Jacques Cinq-Mars]

Thanks Jacques,

For having posted in the BOOKYARD section the information on "COMPTES-RENDUS PALEVOL: special issue on the 'First Hominids'.
I went to the site you mention. It is indeed very rich in information."

It is interesting to note that, from the abstracts contents (these are the only free available info articles are for a fee) I didn't see a single reference to Yvette Deloison research on a different origin of bipedalism. Remember I mentioned her book in the "Human Evolutionary Biology" discussion, June 07, 2004.

<<La Préhistoire du piéton, Essai sur les nouvelles origines de l'Homme, par Yvette Deloison >>

Her work is not even criticised... But may be it is in the full articles…

It is interesting to see how difficult it is to get the attention of learned specialists, even as an other learned specialists as is Yvette Deloison who is a member of the French National Research institute (CNRS)...

It seems that it is difficult to go against a well installed paradigm, even just to test a new idea.

Paul

Paul

It would very unusual for an abstract to contain references, that is, unless the actual article were to deal specifically, for example, with another person’s (or persons’) work/hypothesis. Not to mention that rarely do abstracts correspond to the true meaning of the word! So, I would not make too much –- as you seem to be willing to do -- of Ms. Deloison’s absence from the documents you have read so far. As you say yourself, “maybe it is in the full articles…”

Jacques

[trehinp]

Paul

It would very unusual for an abstract to contain references, that is, unless the actual article were to deal specifically, for example, with another person’s (or persons’) work/hypothesis. Not to mention that rarely do abstracts correspond to the true meaning of the word! So, I would not make too much –- as you seem to be willing to do -- of Ms. Deloison’s absence from the documents you have read so far. As you say yourself, “maybe it is in the full articles…”

Jacques

You're right Jacques,

My apologies, I was a bit too hasty in my tentative conclusions.

The theory presented by Dr Deloison seemed to me important and challenging enough as to foster either an answer to refute it or to criticise it in such a way that it would be the theme of an article, hence be in the abstract.

I am not enough of an expert, actually not an expert at all in this domain. As a result reading her book felt rather convincing. But before admitting the theory she presents as reasonable, I would have liked to see a debates by specialists of that field.

This post and the previous ones are pleas for help in understanding more about that theory. Perhaps some PALANTH members will have full access to the "COMPTES-RENDUS PALEVOL: special issue on the 'First Hominids'." and will be able to make comments on my remarks.

Note that while looking again for Yvette Deloison work I've found some positive assessment of her work :
http://www.hominides.com/html/dossiers/bipedie.html

Apparently she is not the only one to question the current interpretation of bipedalism apparition in the evolution of primates and what that entails with regard to the Last Common Ancestor nature...
 
Looking forward to some expert comments.

Paul

[Daryl Habel]

I am not enough of an expert, actually not an expert at all in this domain. As a result reading her book felt rather convincing. But before admitting the theory she presents as reasonable, I would have liked to see a debates by specialists of that field.

Hi Paul,

I'm not the expert you seek to answer your questions, but I've probably read more extensively on the subject (locomotion of the last common ancestor) than you.  I hestiate to mention this, but it seems as though you are lamenting a lack of debate on this subject.  On the contrary, the debate over the form of locomotion our last common ancestor (LCA) possessed (quadrupedal, bipedal, or someting intermediate?) is a very active debate that has been questioned for decades.  One might get the impression from reading many popular books that generalize on the origins of human beings, that the last common ancestor of man, chimp, and gorilla, was probably a "knuckle-walker", since many books state this, reasoning that "knuckle-walking" is such a specialized way of locomotion that it is more parsimonious to assume pan-gorilla knuckle-walking was shared with the LCA, and that humans evolved into bipeds from a knuckle-walking ancestor.  But that is not a view shared by all researchers.  In fact, there are many experts who have published alternate views, including the possibility of a LCA which already possessed some degree of bipedalism.  Deloison is not proposing anything with this aspect (bipedalism) of her book that has not been proposed and debated countless times before.   Rather, she seems more interested in revising current phylogenetic reconstructions.

This post and the previous ones are pleas for help in understanding more about that theory. Perhaps some PALANTH members will have full access to the "COMPTES-RENDUS PALEVOL: special issue on the 'First Hominids'." and will be able to make comments on my remarks.

Sorry, no access for me, but if you are interested I have many pdf files of papers related to this question of possible bipedalism in the LCA.  I can e-mail some of these to you if you are interested.  Write me offline at Dar_83001@yahoo.com.

Note that while looking again for Yvette Deloison work I've found some positive assessment of her work :
http://www.hominides.com/html/dossiers/bipedie.html

Apparently she is not the only one to question the current interpretation of bipedalism apparition in the evolution of primates and what that entails with regard to the Last Common Ancestor nature...
 
Looking forward to some expert comments.

Paul

Interesting webpage.  After translation to English, I've gone over this webpage to see what it is that Deloison is proposing that is "novel".  It seems that the most novel idea that she is attempting to persuade us to believe, is that australopithecines (afarensis and australopithecus) are not in our direct line of ancestry (if I translated correctly, Orrorin tugensis leads to humans H. ergaster and sapiens, without an australo in the line).  She cites the "law of Bollo" (irreversibility of evolution) and elements in the human hand and foot for this conclusion.  I'd be a bit skeptical about (inevitable) "irreversibility of evolution".   Evolution is not a "progressive" process leading to any "idealized" condition.  Rather it is a process which aimlessly follows response to ecological change.  Probably not the best analogy, but think about the ancestry of whales.  Fishy Cambrian ancestors that walk on the land until  the end of the Mesozoic 65 million years ago, then they return to the oceans and lose their legs.  If that isn't some sort of reversal, I don't know what is.

But like you, I'd welcome all comment and criticism from a real expert.

Dar

[Daryl Habel]

(snip)
 She cites the "law of Bollo" (irreversibility of evolution) and elements in the human hand and foot for this conclusion.  I'd be a bit skeptical about (inevitable) "irreversibility of evolution".   Evolution is not a "progressive" process leading to any "idealized" condition.  Rather it is a process which aimlessly follows response to ecological change. 
(snip)
Dar

By accident today I happened across a reference to Dollo's (not Bollo as the webpage reads) principle (1893) of irreversibility:

Dollo, L. (1893). Le lois de l'evolution. Bull. d.l.Soc. Belge. d. Geol...., 7: 164-166.

This was referenced in Sarmiento (1987):

Sarmiento, E.E. (1987).  The phylogenetic position of Oreopithecus and its significance in the origin of the Hominoidea.  American Museum Noviates, no. 2881, pp. 1-44.

In Sarmiento's section titled "Oreopithecus and Dollo's Law" (p. 24-34), he states: "...As noted by evolutionary theorists (Gregory, 1920; Mayr, 1963: Simpson, 1941) reversibility is a regular process of evolution.  As long as certain features occur as a matter of variation, the possibility of reversals always exists (see page 14 and Darwin, 1871).  The principles of irreversibility more aptly applies to structures composed of a number of anatomical elements and not to disassociated features.  While it is conceivable that the length of a digital ray could increase and decrease many times during the evolutionary history of a lineage, loss of a ray can never be regained without leaving a record that the new ray is not homologous to the original one.  In Oreopithecus the traits which have been proposed as examples of Dollo's principle are not indisputedly irreversible features.  These traits find an analog with fluctuations in the length of the ray rather than with its loss and reappearance..." (Sarmiento 1987:24).

I'd have to read Deloison's original source material to know exactly what she finds in the hand and foot of Australopithecus that, according to her, adheres to the principle(s) of Dollo, but again I'd advise caution in blind acceptance of a determination of irreversibility in evolution.

Dar

[trehinp]

Rather than opening up a new discussion, I prefer to post here about another controversial theory about bipedalism which was presented in a TV show on the Germano-French TV Channel "ARTE" yesterday night, October 29 2005:

"Homo Sapiens - Une nouvelle histoire de l'homme. Un os dans les théories de l'évolution, le sphénoïde ! "

"Homo Sapiens - a new history of man. A bone(*) in the theories of evolution, the sphenoid !"

See some explanations, in French, about that TV show here : http://www.hominides.com/html/references/homo-sapiens-dambricourt-chaline.htm

The show presented an alternative analysis to the now renowned "East Side Story", dear to  Yves Coppens as well as a great number of palaeontologists linking the origins of bipedalism to climatic changes, triggering the disappearing of forests to the benefit of Savannas vegetation.
 
The analysis presented in the TV broadcast proposes that bipedalism was already acquired while hominids were still living in trees in the forest.  The research conducted by a French palaeontologist, Anne Dambricourt Malasse, is based upon the analysis of the evolution of a small bone structure, the sphenoid, which would have caused radical transformation of the shape and position of the skull via successive mutations independent of climatic changes. Pr Philipp Tobias, of Witwatersrand University of South Africa, gave her several new skuls to analyse. And that confirmed her hypothesis.
 
It is clear that this fundamental questioning of the "East Side Story" theory provokes strong reactions among the palaeoanthropology authorities. One can note that Toumai discovery had already challenged that theory...
 
Even though I'm not a specialist of bipedalism, Anne Dambricourt's theory seems to me fitting better the neo-Darwinian theory that that of the "East Side Story" linking bipedalism to an adaptation to the environment. In fact, this interpretation has some Lamarckian connotations, placing bipedalism acquisition after a change in climate. On the contrary the fact that some hominids might have had acquired bipedalism while still living in trees would have given those individuals with that capability an evolutionary advantage for survival when a change in climate happened later on. This would correspond to the concept of exaptation dear to Gould.

I'd be glad to hear what some specialists think about that hypothesis.
 
Paul Trehin.
 
(*) play on word: in French a "bone" can be used meaning that an thing or an event is a hitch for something. Maybe “a stone in the shoe” could be an equivalent expression in English…

[trehinp]

Once again, rather than openning a new topic, I prefer to expand on bipedalism in this old one...

Here is a short summary of a recent publication on new foot prints datin 1.5 millon years

Newswise — The George Washington University professor Brian Richmond and his colleagues have discovered a set of 1.5 million-year-old human ancestor footprints in Kenya that show the earliest direct evidence of a modern human style of upright walking called bipedalism. The discovery of ancient hominin footprints is an incredibly rare event, and the new prints are the second oldest in the world after the 3.7-million year-old prints in Laetoli, Tanzania, making this one of the most important discoveries in recent years regarding the evolution of human walking. For the first time ever, research establishes a methodology for three-dimensional analysis and comparison of ancient human footprints.


For more information about the Center for the Advanced Study of Hominid Paleobiology, Click here to visit their site.

This is not my field of research at all but I thought that a few of you might be interested...

Paul