Where does shuffle collide?

In molecular evolution, exon shuffling is the recombination of exons (the coding segments of genes) so that modules encoding protein domains are duplicated or joined in new combinations to build novel proteins. Gilbert's 1978 Why genes in pieces? proposed that the split structure of eukaryotic genes, with exons separated by introns, allows this reassortment and speeds the evolution of new functions. The referent is a genomic recombination process, inferred from shared domains and intron positions across proteins, and it is a different construct from randomizing a deck of cards or the data-regrouping stage of a computation.[1]

Unit

The rate at which exons recombine into new domain combinations

Recovery means

Not applicable

Measured by

Inferred from shared protein domains, intron phase conservation, and module boundaries across genes

In probability, the riffle (or dovetail) shuffle is a mathematical model of mixing: a deck is cut into two packets that are interleaved, and the question is how many such shuffles are needed before the order is effectively random. Bayer and Diaconis's 1992 Trailing the dovetail shuffle to its lair solved the model and produced the famous result that about seven riffles suffice to mix a 52-card deck, with randomness setting in sharply around that point. The referent is a Markov mixing process on permutations, measured by how fast its distance from the uniform distribution falls, and it is unrelated to gene recombination or a computational shuffle stage.[2]

Unit

The number of shuffles until the deck's order is effectively uniform

Recovery means

Not applicable

Measured by

Quantified by the total-variation distance from the uniform distribution as a function of shuffle count