Teilhard de Chardin, Pierre - Phenomenon of Man - Reuse of designs
Type of Spiritual Experience
A description of the experience
Pierre Teilhard de Chardin – Phenomenon of Man
And at this extreme beginning of their sub-aerial life [the amphibian of the Permian era], the vertebrates display a surprising characteristic which we must pause to consider. In every variety, the skeletal formula is the same, particularly in the number and composition of the locomotory limbs, to say nothing of the marvellous similarities of the cranial bones. What is the reason for this?
The fact that all amphibians, reptiles and mammals have four legs and only four, might be explained in terms of mere convergence towards a particularly simple mode of locomotion (though the insects never have less than six legs).
But how are we to justify in purely mechanical terms the complete similarity of structure in these four appendices? In the anterior pair, the single humerus, then the two bones of the forearm and the five digits of the hand. Is not this, yet again, one of those accidental combinations which could only once have been discovered and accomplished?
Despite their extraordinary variety, terrestrial air breathing animals can only represent variation superposed on a very special solution of life.