Points of 235 bacterial genomes mapped to a regular tetrahedron with a height of 1 and edge lengths of /2. Here, the face of the tetrahedron towards the observer is flat against the plane of projection. The points are mapped according to Z-curve coordinates with an origin in the center of the tetrahedron. The two spheres in the figures are an inscribed sphere of a regular tetrahedron with a radius of 0.25 and the sphere calculated by Zhang and Zhang . Forty five percents of the points P are found outside the inscribed sphere thus violating the "constraint."