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Author Topic:   Laetoli footprints and modern design
Speel-yi
Inactive Member


Message 1 of 5 (60685)
10-13-2003 2:41 AM


There has been some idea that australopithecine feet were fully human, this is in reference to the thread

www.evcforum.net/cgi-bin/dm.cgi?action=page&f=12&t=168&p=4 -->www.evcforum.net/cgi-bin/dm.cgi?action=page&f=12&t=168&p=4">http://www.evcforum.net/cgi-bin/dm.cgi?action=page&f=12&t=168&p=4

where a "lively" discussion about the evolution of the human brain was being debated. The thread was closed before I could rebut a point.

The footprints at Laetoli have shown that fully bipedal hominids did indeed have a developed arch, but there is a lack of actual fossil evidence that matches the footprints since there have been few complete feet recovered from any site. This can possibly lead to some mistaken conclusions:

http://www.answersingenesis.org/docs/1304.asp

Where we have:

quote:
We could not wish for clearer evidence from an evolutionist that it is only his (and his colleagues’) evolutionary assumptions that force him to reach evolutionary conclusions. There are many similarities between apes and man, but one of the most distinctive differences is the feet. Ape feet are like our hands, with an opposable big toe (like our thumb). Human feet are different from any in the animal world-no other has feet like ours.

In contrast to the previous site we have:

quote:
Instead, White tried to fit the foot of A.
afarensis to the Laetoli prints. This was very difficult because
no complete foot skeleton of A. afarensis had been found at the
Hadar site. A partial foot skeleton, however, had been recovered.
This was the AL 333-115 foot skeleton, which included only bones
from the front part of the foot--phalanges and metatarsal heads.
According to White, the best tracks at Laetoli were in the G-
1 trail, representing the smallest of the three individuals of
the G group. Even White admitted that the phalanges of AL 333-115
were "obviously incompatible with the G-1 tracks" (White and Suwa
1987, p. 497). Stern and Susman, and Tuttle, found them
incompatible with any of the tracks. White, however, pointed out
that the AL 333-115 individual represented one of the larger,
presumably male, members of the First Family group and proposed
that the foot of Lucy, one of the smaller, female individuals,
might have fitted the G-1 Laetoli prints.

The preceding was from the site:

http://www.anatomy.usyd.edu.au/danny...
{Shortened display form of URL, to restore page width to normal - AM}

A reconstruction of the afarensis foot results in an 'foot triangle' of 140 degrees in the 3 points of the ankle axis to the distal metatarsals and the calcaneous tip. A modern human foot has only 110 degrees in this angle. Thus it can be seen that the australopithecine foot arch is an intermediate stage between modern humans and the feet of tree dwelling primates.

------------------
Bringer of fire, trickster, teacher.

[This message has been edited by Speel-yi, 10-13-2003]

[This message has been edited by Adminnemooseus, 10-13-2003]


Replies to this message:
 Message 2 by Andya Primanda, posted 10-13-2003 4:53 AM Speel-yi has replied

  
Andya Primanda
Inactive Member


Message 2 of 5 (60693)
10-13-2003 4:53 AM
Reply to: Message 1 by Speel-yi
10-13-2003 2:41 AM


I have a picture of an australopith/Homo habilis foot in my page:
http://redrival.com/evolusi/humevol3.htm7

This message is a reply to:
 Message 1 by Speel-yi, posted 10-13-2003 2:41 AM Speel-yi has replied

Replies to this message:
 Message 3 by Dr Jack, posted 10-13-2003 6:29 AM Andya Primanda has taken no action
 Message 4 by Speel-yi, posted 10-13-2003 4:18 PM Andya Primanda has taken no action

  
Dr Jack
Member (Idle past 1344 days)
Posts: 3507
From: Leicester, England
Joined: 07-14-2003


Message 3 of 5 (60696)
10-13-2003 6:29 AM
Reply to: Message 2 by Andya Primanda
10-13-2003 4:53 AM


Think you got the link wrong there, should it be: http://redrival.com/evolusi/humevol3.htm

This message is a reply to:
 Message 2 by Andya Primanda, posted 10-13-2003 4:53 AM Andya Primanda has taken no action

  
Speel-yi
Inactive Member


Message 4 of 5 (60752)
10-13-2003 4:18 PM
Reply to: Message 2 by Andya Primanda
10-13-2003 4:53 AM


Thanks for the link, a very interesting page, I have seen casts of the habilus foot, but the model I have seen is based on a different foot.

It looks pretty flat by comparison to a modern humans foot, White made a completely subjective statement about the arch.

------------------
Bringer of fire, trickster, teacher.


This message is a reply to:
 Message 2 by Andya Primanda, posted 10-13-2003 4:53 AM Andya Primanda has taken no action

Replies to this message:
 Message 5 by Speel-yi, posted 10-13-2003 4:33 PM Speel-yi has taken no action

  
Speel-yi
Inactive Member


Message 5 of 5 (60755)
10-13-2003 4:33 PM
Reply to: Message 4 by Speel-yi
10-13-2003 4:18 PM


Oh yeah, and I did agree with this from your site:

quote:
However, bipedalism had to evolve from something, if not the quadrupedal knuckle-walking of chimps and gorillas. There are lots of theories offered to explain the origin of bipedalism. I prefer Svend Palm's theory (Palm 1999). Palm proposed that early human ancestors had a mode of locomotion like gibbons (Hylobates). Gibbons were arboreal brachiators, but if they must move on the ground, they do it by walking bipedally without using their hands to touch the ground like chimpanzee knuckle-walking. Palm pointed that about 10 million years ago, well before the human-chimp molecular split, a change of climate reduced the amount of trees and converted dense forests into sparse forests and plains, thus forcing ancient gibbon-like apes to spend more time on the ground. This condition served as a trajectory of the evolution of human bipedalism. Chimpanzee knuckle-walking may be a derived condition from bipedalism. Roughly, chimps might even be considered descendants of early bipedal humans!

Knuckle-walking is less efficient for movement on the ground than bipedalism, so you would predict it would evolve in an environment that was more heavily forested, while bipedalism would evolve in a sparse forest. Early hominids didn't evolve bipedalism to get out of the trees, they evolved it to stay in the trees.

------------------
Bringer of fire, trickster, teacher.


This message is a reply to:
 Message 4 by Speel-yi, posted 10-13-2003 4:18 PM Speel-yi has taken no action

  
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