Bipedalism on an Arbitrary Scale

The next step in the process of acquiring information is to move past what we can think of onto what we can see. That is, we have the way things are done and how to do them but we have not yet touched the work. In this case, we begin by reviewing some information regarding a trend towards bipedalism based on an arbitrary scale. That is, we use  diagnostic features we can see and judge for ourselves.

Although some may believe arbitrary assessments to be vague or assumptive, this step is sometimes used by those who know about the subject. That is we have spent many weeks getting to the point where you are trained observers. That is what you see matters and you will now “show what you can do with what you know.”  This quick step is used to give immediate feedback to guide the path of inquiry. For example, an arbitrary scale can give values which can be interpreted as useful or not.

The values can also be added to a graph which may show connections, divergence, and trends. Although the arbitrary assessments may be cursory they can be used to help make predictions. The predictions can aid in a direction of inquiry such as future experimental design to pursue a lead or quickly and simply rule out an assumption.

An assumption in science can be either a premise for an idea based on experience, or a prediction based on prior data. That is, the premise from an informed  previous statement can lead to inquiry. Informed statements come from experience or existing data. Therefore, an assumption in science is very different from how assumptions are used in daily activities by many non-scientists.

Here we may assume that the diagnostics features listed in the drawing plantigrade, digitigrade, unguligrade highlight things of interest in relation to patterns of  locomotion, in this case distinctions of speed and power compared to bipedalism.

Grade scale x/30 x 20 = score

12.1. Bipedalis.Start with an ABC about each foot grade.

Now that we have gone past the basics and the surprise that other animals have very similar skeletal structures it is time to review the basics of locomotion. Later, other forms of locomotion will be investigated in depth, but, for now it is wise to stay with what is familiar and the basic three.

On the drawing for anthbiolab.mckendricksj.footgrades.plantigrade.digitigrade.unguligrade above, observe the normal standing postures and note the following for each species A, B,and C:

1. (3 points) On the drawing above note the angle of the hip to the femur by the scribed line(s) down to the caudal line (a line towards the tail) of the hip in connection to the femoral line (of the femur). Estimate the angles of hip to femur by selecting the answer(s) which fits (delete the wrong answers) for each species:

Species A what is angle 1 =

1. Near to 180 deg
2. Near to 115 deg.
3. Near to 95 deg.

Species B what is angle 1 =

1. Near to 180 deg
2. Near to 115 deg.
3. Near to 95 deg.

Species C what is angle 1 = 

1. Near to 180 deg
2. Near to 115 deg.
3. Near to 95 deg.

1. (1 point) Note the location of the calcaneus relative to the point of contact at ground level and length relative to the tibia by selecting the answer(s) which fits (delete the wrong answers) for each species:

Species A the location of item 2, the calcaneus to the ground is-

1. On the ground and shortest compared to tibia
2. Off the ground and longer compared to tibia
3. Very high off the ground and longest compared to tibia

Species B the location of item 2, the calcaneus to the ground is-

1. On the ground and shortest compared to tibia
2. Off the ground and longer compared to tibia
3. Very high off the ground and longest compared to tibia

Species C the location of item 2, the calcaneus to the ground is-

1. On the ground and shortest compared to tibia
2. Off the ground and longer compared to tibia
3. Very high off the ground and longest compared to tibia
4. (1 point) Note the relative length of the metatarsals compared to the other species by selecting the answer(s) which fits (delete the wrong answers) for each species;

Species A

1. Short
2. Short to medium
3. Very long

Species B

1. Short
2. Short to medium
3. Very long

Species C

1. Short
2. Short to medium
3. Very long
4. (1 point) Note the position of the pedal phalanges in relation to the metatarsals especially note hooves as on the ground but not the pahalages by selecting the one answer which fits (delete the wrong answers) for each species:

Species A

1. On-ground- inline
2. On-ground-not-inline
3. Off-ground-not- inline

Species B

1. On-ground- inline
2. On-ground-not-inline
3. Off-ground-not- inline

Species C

1. On-ground- inline
2. On-ground-not-inline
3. Off-ground-not- inline
4. (1 point) Note the pedal phalanges in relation to the tiba phalanges by selecting the answer(s) which fits (delete the wrong answers) for each species:

Species A

1. On-ground- and 90 deg.
2. On-ground- and greater than 90 deg.
3. Off-ground- and greater than 90 deg.

Species B

1. On-ground- and 90 deg.
2. On-ground- and greater than 90 deg.
3. Off-ground- and greater than 90 deg.

Species C

1. On-ground- and 90 deg.
2. On-ground- and greater than 90 deg.
3. Off-ground- and greater than 90 deg.
4. (1 point) If a species has an angle of femur to hip bone is closer to 90 deg., then they are better at jumping without a run. Select the species one or more which has that by selecting the answer(s) which fits (delete the wrong answers) best for power related to speed and jumping:

A: human

B: Dog

C: Deer

1. (1 point) If a species has a calcaneus not in contact with the ground and has a longer length relative to the tibia, then they are able to have a burst of speed and jump easily exceeding what humans can do. Select the species, one or more, which has that characteristic by selecting the answer(s) which fits (delete the wrong answers) best for power related to speed and jumping:

A: human

B: Dog

C: Deer

1. (1 point) If a species has a relatively longer calcaneus length when compared to the other species then they are better at jumping without a run. Select the species one or more which has that by selecting the answer(s) which fits (delete the wrong answers) best for power related to speed and jumping:

A: human

B: Dog

C: Deer

(1 point) If a species has pedal phalanges in relation to the metatarsals which are not in line and have less contact overlength to the ground then they are able to have a burst of speed and jump easily exceeding what humans can do. Select the species, one or more ,which has that characteristic by selecting the one answer which fits (delete the wrong answers) best for power related to speed and jumping:

A: human

B: Dog

C: Deer

10.  (1 point) If a species has the tibia in relation to the pedal phalanges which are in excess of 90 degrees then they are able to have a burst of speed and jump easily exceeding what humans can do. Select the species one or more which have that by selecting the one answer which fits (delete the wrong answers) best for power related to speed and jumping:

A: human

B: Dog

C: Deer

11.  (10 points) From questions 1 thru 5 fill in the table to evaluate which species ranks the lowest for power for speed and jumping. Total each time A species scored a 1.

12.  (2 points) Questions 1 thru 5 and 11 indicate that Species A is unique. What are they limited by, what can’t they do?

13.  (2 points) Questions 6 thru 10 indicate that species B and C have less limitation and can do what?

14.  (6 points) Why is this interesting to learn that humans even when compared to dogs and deer, to say nothing about them to top predators, have far less abilities in relation to their bipedalism?

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