C value paradox describes the lack of relationship between genome size and organismal complexity (Buchanan Biochemistry and Molecular Biology of Plants, 2nd Edition p. 405). I wonder if this description is valid in terms of genome complexity.
In this case: Is there a lack of relationship between organismal complexity and genome complexity?
I doubt it. While we can envision measures of organismal complexity that are independent of their genomes, there isn't really an unambiguous independent definition for genome complexity. I would guess that any genome complexity estimate would include genome size to some degree (e.g., number of loci, number of regulatory elements, etc.). That makes these two concepts correlated and would eliminate the chance for a "paradox" in which they were unrelated.
Scientists now have the ability to sequence complex genomes from multicellular organisms. Does the genome size correlate with the complexity of the organism? The answer is surprising.
Complex Genomes: Shotgun Sequencing
By: Jill U. Adams, Ph.D. (Freelance science writer in Albany, NY) © 2008 Nature Education
Citation: Adams, J. (2008) Complex genomes: Shotgun sequencing. Nature Education 1(1):186
http://www.nature.com/scitable/topicpage/complex-genomes-shotgun-sequencing-609
Dear Aleš,
With all respect why « trivial » ? The cybernetic analogy (with your proposed « exploration and exploitation searches ») as applied to biology is surely fascinating but it is still just speculation : no reproducible proof tests, no falsibiability. Interesting conjectures even if abundantly cited (as the ER=EPR conjecture in quantum gravity) are not proven facts (like that the Earth turns around the Sun). They are just put forward to trigger further research. This is also what the articles conclude :
Tyagi : « Genome-wide studies of noise in related organisms, or in the same organism under different conditions, such as stress or aging, will allow researchers to determine whether noise is simply a limitation of the gene expression apparatus or an essential trait subject to evolutionary selection and refinement. »
Adams : « Multicellular genomes have yet to reveal all of their secrets, however. While comparison to unicellular genomes has helped define the basic genes required for all life, the genes and splice variants found in complex metazoan genomes promise to elucidate how limbs, organs, and behaviors are sculpted. As the genomes of more and more species are sequenced, scientists will gain even greater insight as to how to read the genomic blueprint and understand how life is encoded in DNA. »
That there is poor correlation between genome dimension and « complexity » is a known issue (maybe over 30 years …). There is e.g. a huge number of bp (base pair) repetitions and introns in the human genomes without known informative content. First of all, what one means with « complexity » in the context must be defined. We share 98% of our DNA with chimpanzees but genetic organization might be locally different in both species.
However, I agree with Ashley that there is some rough correlation anyway : bacteria have globally less protein coding genes than eukaryotes, or less gene density and chromosome numbers than mammals.
Dear Aleš,
With all respect, I cannot agree with such bold jumps. If genome size is a crude (global view) measure of information complexity and cells execute experimentation (local view), does it necessarily mean that the complexity of the system - which is there under my eyes in the laboratory – is growing ? Such jumps are speculative. They are not falsifiable. Do you know the work of Richard Lenski and coworkers ? By the way, is there established proof that Kolmogorov definition is the right one for biological systems ?
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