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Thou Shall Not Climb!
I need some help...
Could someone be so kind as to explain to me why is it, that a theropod
is automatically banned from the trees unless its first toe is
reversed??? I simply believe that this view seems just a tad bit
dogmatic. As such, it needs to be questioned...
Is there some sort of written law that I've missed that states that
none of those other claws found on the fingers and toes can be used to
scramble up a tree? Is it because the curvatures of the claws are not
EXACTLY PERFECT as compared to expert climbers, so therefore climbing
is strictly forbidden? (When it comes to perching, one usually requires
a greater degree of curvature because the foot alone is doing the
grasping. But in an animal that uses both the foot and hand, the
curvature doesn't need to be as great.)
Using a modern perching bird as the standard from which to base
conclusions on the climbing abilities of basal birds is stretching it
just a bit don't you think?
On that note, what about the curved phalanges in the manus of
Archaeopteryx? Why can't these be interpreted as an indication of
climbing? After all, monkeys and squirrels have the same trait. Also,
the orientation of the unguals on the manus, as well as an increased
range of motion for the shoulder joint in basal birds and their kin,
look to me like something that would come in handy when climbing... And
what about the pecs? Primates = big pec selection, so why not the same
in some smaller theropods??? Big pec selection in theropods =
pre-evolved state for powering flight.
And furthermore, WHY would the 1st toe reverse if the theropod wasn't
already in the trees??? I mean seriously... did some fluffy little
monster decide one day to give birth to other fluffy little monsters
with reversed 1st toes so that they could climb a tree even though the
parent couldn't? Is that what we are saying here?... The toe magically
reversed for no reason, and then theropods decided to climb? How is
that not the implication of what you are saying?
Selection only works if there is a need... How did the need for a
reversed toe start if theropods were not up in the trees before they
needed the reversed toe to be up in the trees???
And perching.... Perching... Perching is not the same as climbing. I'm
sorry, but you might need the reversed toe to perch WHEN YOU ARE A
BIRD... but a reversed toe isn't required equipment for climbing up
trees and holding onto branches.... especially when you have something
called fingers. Let's avoid using today's heavily derived state to
indicate what a basal state should look like.
Maybe... just maybe... a certain group of theropods were scrambling up
into trees... using their feathered arms with their big'ole fingers and
sharp claws... to cling to branches while being assisted by their feet.
But eventually, as the feathered arms became wings, and the fingers
faded away... the feet completely absorbed the job of clinging to the
branches... leading to selection favoring the reversed 1st toe. Why
would such a scenario not be possible?
Given how these animals are preserved, with the added complication of
how that toe attaches, isn't it possible that due to the nature of the
fossil record, we might never be able to tell that it was on its way to
being reversed? (especially if the toe was mobile, which depends on how
firmly the toe was attached to metatarsal 2 by the ligaments).... That
is, until it was nearly or completely reversed. And by then, with no
wing claws, it had to be reversed if the animal was arboreal... Awfully
convenient too, since so many ended up in the trees only after they
were evolved to allow such behavior, right?
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