From: kevin@nuchat.sccsi.com (Kevin Brown)
Subject: Re: Holden Numbering
Organization: I can't see any in the immediate vicinity...
Date: Sun, 23 Aug 1992 02:20:34 GMT

In article <2868@fedfil.UUCP> news@fedfil.UUCP (news) writes:
>In article <Bt8816.HLs@world.std.com>, twalters@world.std.com (Tim Walters) writes:
>> Ted, let's imagine that another of your bursts of radiation bathes the
>> Earth and a bunch of new mutants are created.
> 
>> Is it possible that one of these mutants could get more weight off the
>> ground than Kaz?
>
>In my opinion, no.  By all published accounts, muscle tissue is nearly 
>identical from any vertibrate to any other, so that mouse, human, and
>elephant muscle tissue is hard to tell apart under the microscope.  I
>don't easily see what any further mutation could add to that picture.

This is because, despite the weird scenarios you believe in, you seem to
lack imagination.

Here's an example of a mutation which could get more weight off the ground
that Kaz:


Kaz's arm:

		    |
attachment pt ----->|\
		    ||
		    ||
		    |\
		    | |<-- muscle
		    | |
		    | |
         elbow ---> O--------------------  <-- hand here
		      ^
		      |
		attachment point


Mutant's arm:


		    |
attachment pt ----->|\
		    | \
		    |  -\
		    |    \
		    |     \<-- muscle
		    |      \
		    |       \
         elbow ---> O--------------------  <-- hand here
			     ^
			     |
		    attachment point

The mutant's muscles are *identical* in cross-section and strength to those
of Kaz.  Since the attachment points differ, however, the Mutant will have
the ability to lift greater weight.



Kaz's leg:

			attachment point
				 |      +----- knee joint
		                 v      v
pelvic joint  ----> O-------------------O|
         muscle --> -------------/      ||
					||<-- muscle
					||
                     attachment point-->|/
					|
					|
					|
					|
				    foot here





Mutant's leg:

				        +----- knee joint
					|
					v
		 /--\                 /---\
pelvic joint --> |  |-----------------|   | |
                 \--/       /-------/ \---/ |
      muscle --> ----------/        ^   |   |
			            | 	|   /<-- muscle
			            | 	|  |
				    |   |  |
				    |   | /
				    |   | |
				    |   | |
             attachment points ---> +-->|/
					|
				    foot here

Again, the Mutant's muscles are *identical* to Kaz's.  But the mutant's
joints are much larger than Kaz's, and the attachment points of the
muscles are much closer to the points at which the weight is being
borne, so the mutant has a huge lifting advantage over Kaz.


If you have problems following this, try the following experiment:

Take a piece of plywood, about 3 feet long, and drill two holes in it,
one at about the center and one close to one of the ends.  Take a piece
of rope, and thread it through the hole close to the end, and tie the
end of the rope in a knot so it won't go back through the hole.  Put a
weight on the end with the rope attached and the other end on a table.
Feel how easy it is to lift the end of the plank with the rope.

Now do the same thing, but with the rope attached to the center of the
board.  Feel how much more difficult it is to lift the weighted end of
the plank with the rope when the rope is closer to the "joint" (which
is the end of the plank resting on the table).

This is conclusive proof that the attachment point makes a lot of
difference in how much force the muscle has to exert in order to lift
the weighted end of the lever.

A mutation with much larger joints than Kaz and muscle attachment points
much closer to the ends of the bones will be able to lift much greater
weight than Kaz can, because the muscles are being used much more
efficiently to actually lift the weight rather than putting axial force
on the bones.

The tradeoff is that, with larger joints and attachment points closer to
the ends, the muscles have to contract much more in order to produce the
same amount of movement that the other arrangement would yield with a
smaller amount of contraction.  This means that, if both muscles are of
the same strength (and thus maximum contraction rate), Kaz's arrangement
will allow greater speed of movement of the assembly than the mutant's
arrangement, since in Kaz's arrangement, the muscle doesn't have to
contract as fast to get the same speed of movement.

For a creature that has to be able to run, the larger joints and wider
attachment points will put the creature at a disadvantage.  The smaller
joints and closer attachment points will yield greater running speed and
will thus be better suited to a creature that must run.

For a creature that has to be able to lift heavy objects (which can, of
course, include itself), the larger joints and wider attachment points
will be an advantage to the creature, whereas the smaller joint and
closer attachment point arrangement will put it at a disadvantage.

Kaz is not "optimized" to lift weight because his joints aren't as big as
they could be and his attachment points aren't as close to the ends as
they could be.  Therefore, Kaz cannot lift as much as a mutation that is
"designed" for the task, and therefore a mutation which can lift more
than Kaz is possible.  Thus, Kaz is not the ultimate in lifting ability
for a given size.

>Ted Holden


-- 
				Kevin Brown

			    kevin@nuchat.sccsi.com
			    kevin@taronga.taronga.com
Newsgroups: talk.origins