I belive it is important to consider that "cryptic species" is much more an anthropic point of view of how we (humans) are seeing the species. Of course that cryptic species are in general closely related species. But, in some cases, as in some fungal species, the two "cryptic species" might be genetically isolated for more than 20-30 million of years and we (humans) have difficulties to see them as distinguish species.
I belive it is important to consider that "cryptic species" is much more an anthropic point of view of how we (humans) are seeing the species. Of course that cryptic species are in general closely related species. But, in some cases, as in some fungal species, the two "cryptic species" might be genetically isolated for more than 20-30 million of years and we (humans) have difficulties to see them as distinguish species.
I think any species can be developed as long as they have DNA as a genetics material. Most species have genomic mobile elements that is activated and moved with the genome and make a lot of changes in the genetic material over time.
Article Transposable elements domesticated and neofunctionalized by ...
Its really interesting to look into what is a species? This term itself is more complex to understand. Moreover taxonomic approaches add more to the puzzle. As concern "cryptic species" we tried to make a way on one of our research by proposing putative cryptic species in five cases of fish (Please refer (attached PDF) one of our manuscript). We were having issues in describing five individuals from five fish species which were resembling morphologically similar species but when analysed with COI sequence variation, intraspecific divergence is exceeding (>3%) significantly. Other analyses like bootstrap support and ABGD barcode gap analysis also suggesting for new taxonomic position. We were not having alternative instead of describing these individuals as putative cryptic species.
Now question still remains in discussion whether its on way of speciation? we may quantify how far speciemen in discussion is differing from its neighboring counterpart. Appropriate sampling strategy and considering a complete habitat may lead to accurate quantification using suitable molecular markers (Mt DNA).
Cryptic species is defined by similar phenotype but distinct genetic architecture. Speciation is a reproductive isolation process. My understanding your question is about cryptic species have higher evolutionary rates, which could be examined via DNA analysis. On the other hand, are there more cryptic species than non cryptic species in the same taxa? It is most likely that more parallel evolution scenarios have bee observed in cryptic species. Thus, it appears to be a big missing gap linking cryptic species to more chances of speciation.
The question and discussion seems interesting. I liked the explanation given by Dr. Khedkar and Dr. Zhao. I would add further confusion to the discussion. Do cryptic species are already genetically differentiated species and we still call them cryptic species on the basis of morphological similarities? If my argument is correct then the species can either be already distinctly different from each other and some may be re-productively isolated. If we use the molecular markers alone to decide species distinction then there are some species which are genetically similar but morphologically different. Then, there is no other way than combining morphological and genetic approaches together to differentiate species.
My advice is more technological then theoretical: A term "Cryptic species" means that you cannot recognise it because of a set of cryptic characters. If you may define the meaning: what characters are cryptic, then you may study your question on real taxa. The best way to do it is to review the taxonomic characters, making a taxonomic compendium or taxonomic revision of a taxon (genus, tribe, spaecies group) which is intensively studied last years (pests, indicators, invasive species). Developing of a list of characters (from diagnosae and keys) of neighbour taxa are very efficient because of similar variability.
Actually, I do not understand the basic question. By definition, cryptic species are already "species"! Maybe you are asking something about the dependence on the species concept you are adopting.
In nature there are many examples of sibling or cryptic species ( different species) that are morphologically identical but genetically different. Generally they are sympatric species throughout its range. These species generally adopt the same coloration pattern as in many insects that exhibit warning coloration like the butterfliy Philaethria dido and Philaethria ostara, or Heliconius melpomene and Heliconius erato, are good examples. Check this paper: https://www.researchgate.net/publication/263349148_A_review_of_the_Philaethria_dido_species_complex_%28Lepidoptera_Heliconiinae%29_and_description_of_three_new_sibling_species_from_Colombia_and_Venezuela
Article A review of the Philaethria dido species complex (Lepidopter...
In the Canary Islands we have good examples of cryptic species with some birds, e.g. Fringilla polatzeki (proposed to be segregated from F. teydea) and the complex of "Afrocacanarian" Blue Tits (Cyanistes teneriffae - species group). Recent tendences in taxonomy, based on genetics, morphometrics and acoustics, show that some of our local subspecies merit a full species status.