It relates to the paradox that would emerge if the majority of eukaryotic non-coding DNA were assumed to be functional and the difficulty of reconciling that assumption with the diversity in genome sizes among species.
So why can A. altyncolicum make do with one fifth as much regulation, structural maintenance, protection against mutagens, or [insert preferred universal function] as A. ursinum?Some researchers argue that the onion test is related to wider issues involving the C-value paradox and is only valid if one can justify the presumption that genome size has no bearing on organismal physiology.
Ryan Gregory knew that most so-called explanations look very silly when you try using them to account for genome size in onion species.Ewan Birney (then head of the ENCODE Project) explained the difference as a product of polyploidy,[14][15][better source needed] and therefore not relevant to the discussion of humans.
(re: onions etc); polyploidy and letting your repeats "go crazy" (bad piRNAs anyone) mean your genome can be v. big Similar claims were made by John Mattick in an article defending the ENCODE project against arguments disputing the main finding of the project:[16] The other substantive argument that bears on the issue, alluded to in the quotes that preface the Graur et al. article, and more explicitly discussed by Doolittle, is the so-called ‘C-value enigma’ , which refers to the fact that some organisms (like some amoebae, onions, some arthropods, and amphibians) have much more DNA per cell than humans, but cannot possibly be more developmentally or cognitively complex, implying that eukaryotic genomes can and do carry varying amounts of unnecessary baggage.
Moreover, there is a broadly consistent rise in the amount of non-protein-coding intergenic and intronic DNA with developmental complexity, a relationship that proves nothing but which suggests an association that can only be falsified by downward exceptions, of which there are none known.Freeling et al. proposed a genome balance hypothesis that presumably accounts for the C-Value Paradox and passes the Onion Test.