The "C-Value Paradox"
chart shows the range of C-value [genome size,
measured as number of Kbp of
DNA] for a variety of organisms. So-called "simple"
prokaryotic organisms in general have less DNA per
genome than do more "complex," eukaryotic organisms, such as
plants and animals. The
refers to the observation that genome size does not uniformly
respect to perceived complexity of organisms, for example
vertebrate with respect to invertebrate animals, or "lower"
versus "higher" vertebrate animals (red box). Note for
examples that some Amphibians have more than 10-fold more DNA than do Mammals,
There is in fact no "paradox." Evolution
proceed in a linear manner, nor is there a linear
succession of organisms from "lower" to "higher." Despite
in DNA content, the
number of genes in any vertebrate genome is roughly
similar. Also, plant and amphibian genomes in particular are
in which the chromosome number undergoes doubling to two-,
eight-fold. without a radical change to the form of the
Figure © 2005 Griffiths et al.; All text
material © 2011 by Steven