Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 84 (8914 total)
Current session began: 
Page Loaded: 06-19-2019 4:00 AM
23 online now:
Tangle (1 member, 22 visitors)
Chatting now:  Chat room empty
Newest Member: 4petdinos
Post Volume:
Total: 854,110 Year: 9,146/19,786 Month: 1,568/2,119 Week: 328/576 Day: 3/128 Hour: 0/1


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Bipedalism in apes: a plesiomorphic trait?
Doddy
Member (Idle past 4075 days)
Posts: 563
From: Brisbane, Australia
Joined: 01-04-2007


Message 1 of 14 (425191)
10-01-2007 5:19 AM


I recently came across a creationist espousing a book titled The Upright Ape.

I haven't actually read it, but the author, a spinal neurosurgeon, is suggesting that humans evolved from a bipedal ape. That is, quadrapedalism is apomorphic for modern apes like chimps and gorillas.

I was able to get two quotes from the book. One from the preface:

quote:
In part, this book details what I have discovered since the day in 1981 when David Pilbeam placed in my hands the problem of explaining a seemingly inexplicable 21-million-year-old fossil. This bone had the totally unique features found in humans, but it was from a creature that lived 15 million years too soon. There should not have been anything that looked like this until the human-chimp split 6 million years ago. I believe this conundrum can be explained, but Darwinian Evolutionary Theory as it now stands cannot provide everything that is required to explain it.

And one from the conclusion:

quote:
The first upright ape was also human. In the millions of years that followed, new species branched off and abandoned their upright posture to descend to what we now call "ape."

What do you think? Sound plausible in the least? Honestly, I think it violates everything I know about 'maximum liklihood' cladistics (i.e. not much). How could all apes bar one end up with the hunched over character....how could our spine be so screwy if it had evolved for that long...how could the other fossils be interpreted so wrongly?

Is the author a quack?

Human origins, please.


Help to inform the public - contribute to the EvoWiki today!

What do you mean "You can't prove a negative"? Have you searched the whole universe for proofs of a negative statement? No? How do you know that they don't exist then?!


Replies to this message:
 Message 3 by Modulous, posted 10-01-2007 12:23 PM Doddy has not yet responded
 Message 4 by Chiroptera, posted 10-01-2007 12:31 PM Doddy has not yet responded
 Message 8 by arachnophilia, posted 10-03-2007 9:11 PM Doddy has responded

    
AdminNosy
Administrator
Posts: 4754
From: Vancouver, BC, Canada
Joined: 11-11-2003


Message 2 of 14 (425214)
10-01-2007 9:53 AM


Thread moved here from the Proposed New Topics forum.
  
Modulous
Member (Idle past 269 days)
Posts: 7789
From: Manchester, UK
Joined: 05-01-2005


Message 3 of 14 (425223)
10-01-2007 12:23 PM
Reply to: Message 1 by Doddy
10-01-2007 5:19 AM


The first upright ape was also human. In the millions of years that followed, new species branched off and abandoned their upright posture to descend to what we now call "ape."

Nonsense. The first upright ape, according to this find was Morotopithecus and its close cousins had the potential ability of bipedal locomotion. It is possible that the other great apes had an ancestor that was able to walk upright. I have no reason to suspect that this fact, should it be true, means that current Evolutionary Theory as it now stands cannot explain it.

How could all apes bar one end up with the hunched over character

That question can be asked without this being an issue, we are uniquely bipedal -why? The question is why did evolution modify this trait in us so that we are bipedal specialists (Morotopithecus would probably have not been exclusively bipedal from what I have read), when it modified all the other surviving lineages to have less bipedalism?

how could our spine be so screwy if it had evolved for that long

Our spines of course, have been evolving for much longer. However, there is the possibility that our lineage flirted with both bipedalism and quadrapedalim for some time before evolving into the specialists we are.

Edited by Modulous, : No reason given.


This message is a reply to:
 Message 1 by Doddy, posted 10-01-2007 5:19 AM Doddy has not yet responded

Replies to this message:
 Message 5 by RAZD, posted 10-01-2007 4:40 PM Modulous has responded

  
Chiroptera
Member
Posts: 6623
From: Oklahoma
Joined: 09-28-2003
Member Rating: 4.7


Message 4 of 14 (425226)
10-01-2007 12:31 PM
Reply to: Message 1 by Doddy
10-01-2007 5:19 AM


I don't know whether it is relevant to the OP exactly, but this past summer I linked to a BBC article about a proposal that bipedalism evolved among our arboreal ancestors to aid in walking along thin branches, and that it is the obligate bipedalism of the more terrestrial apes that is the derived feature.

In that context it seems plausible.


In many respects, the Bible was the world's first Wikipedia article. -- Doug Brown (quoted by Carlin Romano in The Chronicle Review)
This message is a reply to:
 Message 1 by Doddy, posted 10-01-2007 5:19 AM Doddy has not yet responded

  
RAZD
Member
Posts: 19871
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 5.3


Message 5 of 14 (425280)
10-01-2007 4:40 PM
Reply to: Message 3 by Modulous
10-01-2007 12:23 PM


Nonsense. The first upright ape, according to this find was Morotopithecus and its close cousins had the potential ability of bipedal locomotion. It is possible that the other great apes had an ancestor that was able to walk upright. I have no reason to suspect that this fact, should it be true, means that current Evolutionary Theory as it now stands cannot explain it.

I have felt for some time that the capability for bipedalism would be older than currently theorized, and that the range of bipedalism vs quadrapedalism is more a matter of degree than of kind. Certainly all members of the hominoid superfamily are capable of walking on two legs in varying degree, as are many old world monkeys (the capuchin "organ grinder" monkey for example).

I looked up Morotopithecus and found several articles discussing the find, such as:

BU Professor Digs Up Clues To Human Origins

quote:
Most primate fossils that date to more than 20 million years ago show adaptations for movement on four legs, called quadrupedalism. The Morotopithecus discovery, however, shows a completely different locomotor pattern: suspensory locomotion, like swinging from branch to branch in trees.

This suspensory pattern is believed to fill an important transitional role in the development of primates. Many anthropologists believe primates evolved from quadrapedal ancestors into suspensory primates and finally into the bipedal creatures we see today in humans.


Click to enlarge

Morotopithecus shows a mixture of both primitive and modern features. It had a face and teeth resembling earlier species, while the lower spine, legs, and shoulders show a new design allowing suspension from branches. Being able to support an upright posture more easily than previous species meant Morotopithecus could more easily take advantage of the food and shelter found in trees.


Hanging from branches would tend to favor adaptation to a body capable of being verticle from head to toe, and would act to "pre-adapt" apes for occasional bipedalism.

(Morotopithecus would probably have not been exclusively bipedal from what I have read)

More like a baboon, a gibbon (without long arms), or an orangutan it seems to me. Capable of bipedalism but not attached to it.

That question can be asked without this being an issue, we are uniquely bipedal -why? The question is why did evolution modify this trait in us so that we are bipedal specialists

Because there was an opportunity for a bipedal ape and our bipedal capable ancestors were able to take advantage of it. Once taken there was not much opportunity for turning back.

Our spines of course, have been evolving for much longer. However, there is the possibility that our lineage flirted with both bipedalism and quadrapedalim for some time before evolving into the specialists we are.

Suspensory behavior would also adapt our spines (and hips and knees) for a vertical orientation without requiring much bipedal activity. And our necks and skulls, etc.

Enjoy.


Join the effort to unravel AIDS/HIV, unfold Proteomes, fight Cancer,
compare Fiocruz Genome and fight Muscular Dystrophy with Team EvC! (click)


we are limited in our ability to understand
by our ability to understand
RebelAAmericanOZen[Deist
... to learn ... to think ... to live ... to laugh ...
to share.

This message is a reply to:
 Message 3 by Modulous, posted 10-01-2007 12:23 PM Modulous has responded

Replies to this message:
 Message 6 by Modulous, posted 10-01-2007 9:01 PM RAZD has responded

  
Modulous
Member (Idle past 269 days)
Posts: 7789
From: Manchester, UK
Joined: 05-01-2005


Message 6 of 14 (425342)
10-01-2007 9:01 PM
Reply to: Message 5 by RAZD
10-01-2007 4:40 PM


Because there was an opportunity for a bipedal ape and our bipedal capable ancestors were able to take advantage of it. Once taken there was not much opportunity for turning back.

Well yes, but the question remains: what was that opportunity that was not presented to our uncles?


This message is a reply to:
 Message 5 by RAZD, posted 10-01-2007 4:40 PM RAZD has responded

Replies to this message:
 Message 7 by RAZD, posted 10-01-2007 9:05 PM Modulous has not yet responded

  
RAZD
Member
Posts: 19871
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 5.3


Message 7 of 14 (425344)
10-01-2007 9:05 PM
Reply to: Message 6 by Modulous
10-01-2007 9:01 PM


what was that opportunity that was not presented to our uncles?

The opportunity was there, but there were other opportunities as well, and "our uncles" took one of those other opportunities.

Not everyone becomes a banker to become a millionaire.

Enjoy.


Join the effort to unravel AIDS/HIV, unfold Proteomes, fight Cancer,
compare Fiocruz Genome and fight Muscular Dystrophy with Team EvC! (click)


we are limited in our ability to understand
by our ability to understand
RebelAAmericanOZen[Deist
... to learn ... to think ... to live ... to laugh ...
to share.

This message is a reply to:
 Message 6 by Modulous, posted 10-01-2007 9:01 PM Modulous has not yet responded

  
arachnophilia
Member (Idle past 143 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 8 of 14 (425712)
10-03-2007 9:11 PM
Reply to: Message 1 by Doddy
10-01-2007 5:19 AM


i'll look it over, but i see one startling flaw:

chimpanzees are capable of walking upright. that's oliver the chimp, who had such a tendency to do so that people called him a "humanzee." (genetic tests confirmed that he was entirely chimp, btw).

what's even more truly bizarre is that i'm pretty sure that chimps are better at bipedal locomotion that we are. after all, they don't have pass giant-headed freak babies through their hips. we do.


אָרַח

This message is a reply to:
 Message 1 by Doddy, posted 10-01-2007 5:19 AM Doddy has responded

Replies to this message:
 Message 9 by Doddy, posted 10-04-2007 2:18 AM arachnophilia has not yet responded
 Message 10 by Jon, posted 10-04-2007 2:37 AM arachnophilia has responded
 Message 11 by RAZD, posted 10-04-2007 6:09 PM arachnophilia has responded

  
Doddy
Member (Idle past 4075 days)
Posts: 563
From: Brisbane, Australia
Joined: 01-04-2007


Message 9 of 14 (425792)
10-04-2007 2:18 AM
Reply to: Message 8 by arachnophilia
10-03-2007 9:11 PM


arachnophilia writes:

what's even more truly bizarre is that i'm pretty sure that chimps are better at bipedal locomotion that we are. after all, they don't have pass giant-headed freak babies through their hips. we do.

Depends how you define 'better'. If you do mean being able to do it and still have little complications, then yes they are better. If you mean being able to do it efficiently and quickly (i.e. run), then we certainly outdo the chimps, even the thinner hips (but bigger heads) do cause some problems.


Help to inform the public - contribute to the EvoWiki today!

What do you mean "You can't prove a negative"? Have you searched the whole universe for proofs of a negative statement? No? How do you know that they don't exist then?!


This message is a reply to:
 Message 8 by arachnophilia, posted 10-03-2007 9:11 PM arachnophilia has not yet responded

    
Jon
Inactive Member


Message 10 of 14 (425794)
10-04-2007 2:37 AM
Reply to: Message 8 by arachnophilia
10-03-2007 9:11 PM


what's even more truly bizarre is that i'm pretty sure that chimps are better at bipedal locomotion that we are. after all, they don't have pass giant-headed freak babies through their hips. we do.

Unfortunately, though, chimps are not bipedal, and they are actually worse at it than we are.

quote:
The bones of human legs have a somewhat knock-kneed appearance, with the femur pointing inward toward the knee joint at the valgus angle. This allows human beings to easily transfer the center of gravity directly over the foot in the course of bipedal walking. Ape femurs [which includes chimpanzees] do not angle inward in this manner, so apes waddle when they try to walk bipedally.
...
Finally, the great toe of the ape foot diverges like a thumb from the rest of the digits, a feature that allows apes to use their feet for grasping but inhibits their ability to use this tow for the "push-off" so important for effective bipedalism.¹

Human/Ape²:

There is a slew of other characteristics that make chimpanzees unsuited to habitual bipedalism, from skull structure to pelvic shape; and save for those strange little primates like Oliver, bipedalism's never been the preferred way to go.

Jon
__________
¹ Robert H. Lavenda & Emily A. Schultz, Anthropology: What does it mean to be human? 117
² http://www.amonline.net.au/human_evolution/skeleton/more_info.htm


In considering the Origin of Species, it is quite conceivable that a naturalist... might come to the conclusion that each species had not been independently created, but had descended, like varieties, from other species. - Charles Darwin On the Origin of Species
_ _ _ _ _ _ _ ____ _ _ _ _ _ _ _

En el mundo hay multitud de idiomas, y cada uno tiene su propio significado. - I Corintios 14:10
_ _ _ _ _ _ _ ____ _ _ _ _ _ _ _

A devout people with its back to the wall can be pushed deeper and deeper into hardening religious nativism, in the end even preferring national suicide to religious compromise. - Colin Wells Sailing from Byzantium


This message is a reply to:
 Message 8 by arachnophilia, posted 10-03-2007 9:11 PM arachnophilia has responded

Replies to this message:
 Message 12 by arachnophilia, posted 10-05-2007 1:17 AM Jon has not yet responded

  
RAZD
Member
Posts: 19871
From: the other end of the sidewalk
Joined: 03-14-2004
Member Rating: 5.3


Message 11 of 14 (426002)
10-04-2007 6:09 PM
Reply to: Message 8 by arachnophilia
10-03-2007 9:11 PM


chimpanzees are capable of walking upright. that's oliver the chimp, who had such a tendency to do so that people called him a "humanzee."

There is also the case of the black macaque:

http://www.msnbc.msn.com/id/5479501/

quote:
A young monkey at an Israeli zoo has started walking on its hind legs only — aping humans — after a near death experience, the zoo's veterinarian said Wednesday.

Natasha, a 5-year-old black macaque at the Safari Park near Tel Aviv, began walking exclusively on her hind legs after a stomach ailment nearly killed her, zookeepers said.


Click to enlarge

Natasha, a 5-year-old black macaque, walks at the Safari Park near Tel Aviv on Tuesday.

This really shows how unremarkable the human ability to walk upright really is - when looked at in comparison to other primates it is really a difference of degree.

The only real difference that I can see is that since adapting an upright posture, subsequent human evolution has made it awkward and counter-productive to use a quadrupedal lifestyle (the turkish "hand walkers" notwithstanding). The difference is more that we are no longer able to not use bipedal locomotion.

Enjoy.


Join the effort to unravel AIDS/HIV, unfold Proteomes, fight Cancer,
compare Fiocruz Genome and fight Muscular Dystrophy with Team EvC! (click)


we are limited in our ability to understand
by our ability to understand
RebelAAmericanOZen[Deist
... to learn ... to think ... to live ... to laugh ...
to share.

This message is a reply to:
 Message 8 by arachnophilia, posted 10-03-2007 9:11 PM arachnophilia has responded

Replies to this message:
 Message 13 by arachnophilia, posted 10-05-2007 1:21 AM RAZD has not yet responded

  
arachnophilia
Member (Idle past 143 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 12 of 14 (426077)
10-05-2007 1:17 AM
Reply to: Message 10 by Jon
10-04-2007 2:37 AM


Unfortunately, though, chimps are not bipedal, and they are actually worse at it than we are.

i had heard they expend less energy walking fully erect than we do, not having to swing wide hips back and forth. maybe i've got that backwards, though. the point about the toe does make sense, too.

There is a slew of other characteristics that make chimpanzees unsuited to habitual bipedalism, from skull structure to pelvic shape; and save for those strange little primates like Oliver, bipedalism's never been the preferred way to go.

as an interesting aside, oliver is no longer bipedal in his old age.


אָרַח

This message is a reply to:
 Message 10 by Jon, posted 10-04-2007 2:37 AM Jon has not yet responded

  
arachnophilia
Member (Idle past 143 days)
Posts: 9069
From: god's waiting room
Joined: 05-21-2004


Message 13 of 14 (426078)
10-05-2007 1:21 AM
Reply to: Message 11 by RAZD
10-04-2007 6:09 PM


This really shows how unremarkable the human ability to walk upright really is - when looked at in comparison to other primates it is really a difference of degree.

well, yes. we're more evolved with bipedalism in mind, whereas they are not. it's actually somewhat easy to see the process by which greater adaptations for erect bipedalism would evolve for states very similar to modern apes.

The only real difference that I can see is that since adapting an upright posture, subsequent human evolution has made it awkward and counter-productive to use a quadrupedal lifestyle (the turkish "hand walkers" notwithstanding). The difference is more that we are no longer able to not use bipedal locomotion.

i was thinking of bringing them up. iirc, they are actually slightly anatomically different in terms of ligaments and joints -- but mostly as a result (not the cause) of their quadrapedalism. it's sort of odd to think of bipedalism as at least partly developmental.


אָרַח

This message is a reply to:
 Message 11 by RAZD, posted 10-04-2007 6:09 PM RAZD has not yet responded

  
MauriceAWilliams
Junior Member (Idle past 1650 days)
Posts: 3
From: Cleveland, OH
Joined: 05-07-2008


Message 14 of 14 (465638)
05-08-2008 8:25 PM


I read the book.
Doddy brought up the subject of “The Upright Ape.” She posted a few quotes from the book and asked if anyone had read it. I have just finished reading it, and I posted a review of it on Revish.com.

The author has impressive credentials, both as an anthropologist and as a MD specializing in spinal surgery. His book is about a twenty-two-million-year-old fossil of several lumbar vertebrae from a hominoid primate. His skill as a spinal surgeon helped him recognize that this fossil is from an animal that stood erect and probably could not get about in a crouched position as modern-day apes do. He claims that twenty-two million years is seventeen million years too early for an upright ancestor for humans according to the present understanding of evolution. Therefore, the author felt some reappraisal of Darwinian Theory is justified to explain this fossil and also the very large number of new fossils and discoveries of the past twenty-five years. That reappraisal is what his book is all about.

I think his book is very well organized and contains much valuable information on what is happening in anthropology right now. I disagree with the author’s main conclusion because it does not fit with my Christian faith. I believe humans have spiritual souls; animals do not. I have no problem accepting that humans probably descended from apes. I do have a problem accepting what Doddy quoted from the book:

quote:
--------------------------------------------------------------------------------
The first upright ape was also the first human. In the millions of years that followed, new species branched off and abandoned their upright posture to descend to what we now call "ape."
--------------------------------------------------------------------------------

Edited by MauriceAWilliams, : I left out a few words


  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2019