Bipedism first

[Spektralscavenger]

http://davidpratt.info/ape1.htm#a0

The theory of initial bipedalism, as championed by François de Sarre of the Study and Research Centre for Initial Bipedalism (CERBI), states that instead of being a fairly recent evolutionary transformation of an apelike ancestor, man is an extremely ancient stock and has remained morphologically and anatomically closest to the original vertebrate from which all others descend. In De Sarre’s view, this prototype was a hypothetical tiny marine creature that lived some 60 million years ago.

He describes the mainstream evolutionary history of man as ‘a gigantic farce, based on erroneous observations and old prejudices’, and says that since the palaeontological record is so incomplete we have to rely mainly on embryology and comparative anatomy to discover our real origins. Rather than interpreting man’s primitive (‘juvenile’) structure to mean that humans are fetal apes that have matured, De Sarre argues, as does theosophy, that apes descend from man and have evolved anatomically beyond the point where human development ceased.

Humans are the only known mammals that are habitually bipedal. Significantly, in the embryos of humans, other primates, and many other mammals, the foramen magnum (the opening in the skull through which the spinal column passes) is positioned centrally. In adult humans it retains this position – which is required for bipedalism – whereas in other animals, including apes, the opening migrates backward, as growth proceeds, to the position needed by a quadruped.1

A related fact is that in all mammal embryos, including humans and apes, the angle between the plane of the face and the plane of the base of the skull, through which the spinal cord passes, is extremely flexed – essentially 90°. This angle remains well flexed in adult humans (120°), this being connected with our bipedal mode of locomotion. In adult animals, on the other hand, the angle opens up, rising to 140° in apes, and up to 180° in fully quadrupedal mammals.

[Spektralscavenger]

The more I learn about the human body the more I am convinced that no quadrupedal ever turned into bipedal, whatever the average scientist states. On the contrary; apes, pigs, dolphins, etc came from human-like beings or maybe from (bipedal) dinosaur-like beings. The original bipedals might have been terrestial or aquatic (coasts and shallow lakes).

[Sparky]

maybe from (bipedal) dinosaur-like beings.

grandma and grandpaw

[jtb]

The reason humans can balance standing on one foot is because the foot has 3 points that contact the surface. For example, any other creature would fall over very shortly if attempting to stand on one foot. Is standing on one foot an evolutionary advantage? It is to a chicken. A chicken can sleep balancing on one foot.

[fidelio]

I am surprised that you guys haven't caught on to the best answer out there to this question, seeing as it has been referenced on the Thunderbolts forum a few times already... I'll give you another chance:

http://www.macroevolution.net/hybrid-hy ... ion-2.html