"In the case of birds, however, the major bronchi break down into tiny
tubes which permeate the lung tissue. These so-called parabronchi
eventually join up together again, forming a true circulatory system so
that air flows in one direction through the lungs."
"Just how such an utterly different respiratory system could have
evolved gradually from the standard vertebrate design is fantastically
difficult to envisage, especially bearing in mind that the maintenance
of respiratory function is absolutely vital to the life of an organism
to the extent that the slightest malfunction leads to death within
minutes. Just as the feather cannot function as an organ of flight
until the hooks and barbules are coadapted to fit together perfectly, so
the parabronchi system which permeates it and the air sac system which
guarantees the parabronchi their air supply are both highly developed
and able to function together in a perfectly integrated manner."
"In attempting to explain how such an intricate and highly specialized
system of correlated adaptations could have been achieved gradually
through perfectly functional intermediates, one is faced with the
problem of the feather magnified a thousand times. The suspicion
inevitably arises that perhaps no functional intermediate exists between
the dead-end [bellows] and continuous through-put types of lung. The
fact that the design of the avian respiratory system is essentially
invariant in ALL birds merely increases one's suspicion that no
fundamental variation of the system is compatible with the preservation
of respiratory function. One is irresistibly reminded of Cuvier's view
that the great divisions of nature are grounded in necessity and that
intermediates cannot exist because such forms are incoherent and
non-functional. In his own words: 'Nature...has been settled in...all
those combinations which are not incoherent and it is these
incompatibilities, this impossibility of the coexistence of one
modification with another which establish between the diverse groups of
organisms those separations, those gaps, which mark their necessary
limits...'" (_Evolution: A Theory in Crisis_, by Michael Denton, pp.
210, 212-213)
As Michael Behe (_Darwin's Black Box_) points out, the underlying
molecular machinery which constructs, coordinates and controls these
organs of life is infinitely more complex and difficult to imagine
arising by time plus chance.
So we are left with a choice, either we agree with the evolutionists
that these gaps were *somehow* bridged over time, or we believe that the
various types of animals were created as distinct groups. Which
requires the greater faith?
Bill