RE: [SeattleRobotics] Re: simulation challenge
- Peter Balch said: Sunday, January 02, 2011 6:45 AM
> The terrain has always been rough. The roughness of theI think this misses a significant point. Evolution is not about
> terrain never changed. What changed was how good the walkers
> were. ...
survival of the fittests, but survival of the best situated.
The truer statement is The terrain has always been varied.
The creatures evolving are doing so according to their
Very few fish sharks on mountain sides well above sea level.
While highly successful evolution-wize for survival, the shark
is very poorly situated out of water.
Again, a reference about horses. Developing a barrel racing
timer revealed a rather startling fact. Almost all horses have a
very narrow range of leg length. The average chest height for a
horse is 41". You can go up or down an inch or so. But their
withers can vary greatly from 13 hands to 18 hands (a hand is
4", so from 4'4" up to 6'). This suggests to me horses evolved
in the savanahs where the biggest step over was about 3 feet
high. In other words, in the area the ancestors to modern horses
"evolved" most fallen trees were less than 4' across, or typical
stream banks could be negotiated 4' at a time. In other words,
there were few natural corals in the enviroment they were
situated which would disable their free migration.
So what evolves depends on what the conditions are in the area
of specilization, as they evolve their structure to fit the
situation they find themselves in.
Survival pressure causes more areas to be occupied. But I think
it is wrong to think the terrain has always rough. More
correctly, the terrain attained was the terrain the fit were
situated for, and the more situated by evolution, the more
terrain was occupied.
- --- In SeattleRobotics@yahoogroups.com, Larry Geib <LJGeib@...> wrote:
>I believe that was "my" comment, and not Randy's. Looks like
> it was just a reference to this statement of yours:
> " Few besides mountain goats go anywheres
> near the sort of terrain they live in, and they only handle it because of their significant evolutionary adaptations. Horses,
> deer, elk, moose, etc, can't handle the same slopes, despite
> outward similarity in body designs."
the deer do pretty good on steep slopes.
The pictures don't capture the total actions, but it does look
like the ability of the deer to make large jumps was the key.
Aided by its remarkable visual system being able to pre-plot a
Wish I had a robot that could jump 30' vertically, and land
on its feet. OTOH, just going over broken terrain, short of
vertical cliffs, might be a good next goal.
> I think the pictures in the link I gave show that mule deer, at least, have no problem climbing very steep terrain, even cliff areas. They actually rather like steep country. They have the advantage that they are willing to jump up to 8 feet vertically and 20 feet horizontally in the steepest areas. They often jump with all four feet at once.
> I've often seen them grazing or browsing in pretty rocky country and they will retreat onto the rock if threatened. Steep ground doesn't get as covered in snow, either. They can find food more easily there in winter.
> I'll bet elk would surprise you, too.
> On Jan 4, 2011, at 9:52 PM, "Randy M. Dumse" <rmd@...> wrote:
> > Larry Geib said: Tuesday, January 04, 2011 6:04 PM
> >> Randy is ,akin assumptions without basis again.
> > Sorry, you might have to explain what assumption?
> > I didn't get the reference.
> > Randy
> > -----------------------------------