Randomization of protein encoding gene during species evolution

Employing chi-square teat, the authors observed the bias of 4 kinds of bases’ locating in 3 codon positions in gene sequence, and proved that there is a positive correlation between higher chi-square value and protein coding structure. By this, the observatlon that genes undergo progressive reduction in chi-values along evolution direction will reflect the progressive randomization of gene structures and the loss of the characteristics of protein coding sequences. The result proposed that during the evolution of life, genes are unexpectedly degenerating.