reply to post by spitefulgod
A single non-functioning foot isn't a very good mutation for evolution either. And it's also highly unlikely in evolution.
You could ask the same question the other way around. Why would a snake evolve a single non-functioning leg anymore than it would adapt one? Well it
wouldn't. Neither evolution or adaptation work that way.
You can make evolution look just as much a fool here with that logic because in evolution you can't just evolve an entire leg. Even if it doesn't
function.
So, what we're talking about is the activation of a recessive gene. Most likely because of a genetic error, perhaps the kind that's caused from the
DNA being copied over and over or perhaps the environment.
We know that because in evolution it's impossible to get an entire leg. What would happen is a small mutation of something like an appendage would
start. Then enlarge. Then change shape. Then grow larger over many generations. Eventually that appendage would take on the shape of a leg.
All the while the structures to make the leg work would evolve over time as well. Just like the leg itself. The structures to make the leg work and be
useful can't just pop into existence anymore than an entire leg can. They must slowly evolve over time as well right along with the actual leg.
Because the leg is worthless without the supporting structures to make it work, but so also are the supporting structures worthless without the leg.
Both must evolve along side each other.
It would evolve muscles to maybe move at random. Then back and forth in one direction. Then it might evolve structures to allow for rotation of some
sort. A very slow process.
It is highly unlikely that millions of years ago a fully non-functioning leg evolved with no supporting structures to make the leg work and yet
somehow it provided enough advantage to the snake that the recessive gene wouldn't have been bred out in natural selection by now. In fact, I think
it's easier to believe in sky fairies than that scenario lol. Evolution just doesn't work that way.
Okay, so what can we take away from that? Well, what we can take away from that is, that even though the leg doesn't work, the information stored in
the snake's genetic code to build the supporting units that would make the leg fully functional are most likely STILL in that genetic code somewhere,
but they simply didn't get activated correctly. That's the most logical and simplest explanation we have right now.
The alternative explanation is that snakes spent millions of years evolving one single non-functioning leg that never did work. Not a very likely
scenario based on what we know about evolution.
But the genetic code that controls growth of the supporting structures didn't activate when the leg did? Why? Most likely they're in there, so why
didn't they turn on? Because the gene activated in error. Perhaps due to genetic damage.
That doesn't change in adaptation. In adaptation we have the exact same scenario. All the genetic code to build a fully functioning leg is present
somewhere inside the genetic code. Part of it activated and part of it didn't. Now the leg is broke and doesn't work like it's supposed to?
Why?
I don't know why but whatever explanation evolution provides will probably be the same answer adaptation provides because in this type of scenario
there is no difference between evolution and adaptation. They both make the claim that all the genetic code is already available, but that it can be
damaged. The only difference is where the code came from?
This doesn't answer that question either way.
[edit on 23-9-2009 by tinfoilman]
[edit on 23-9-2009 by tinfoilman]

