Attempts to group plant families by conventional means has not given satisfactory results, and it was hoped that cytochrome c sequences might resolve this problem. Results varied according to the way in which information was given to the computer program, and no consensus tree could be derived. None of the trees seemed reasonable biologically. It appears that cytochrome c sequences in plants are not useful in estimating supposed evolutionary relationships among plant families. Date of the monocot-dicot divergence estimated from chloroplast DNA sequence data.
Angiosperms comprise two separate groups, monocots and dicots.
Monocots and dicots are both found as far back as the record extends. Using chloroplast DNA sequences and assuming a reasonably constant mutation rate for chloroplast DNA, the authors calculated that monocot and dicot lineages diverged approximately 200 Ma before present. The scientific alternative to Neo-Darwinian evolution theory. TWFT Publishers, Costa Mesa, California. Dr. A. E. Wilder-Smith has written some 30 books on the question of origins.