A broad synthesis led by researchers at the University of Arizona indicates that many vertebrate species remain unrecognized because they are cryptic. The study finds that for every currently recognized vertebrate species there are, on average, two unrecognized or “cryptic” species. Senior author John Wiens says many of these hidden lineages have probably been evolving separately for a million years or more, and that some may already be at risk of extinction.
The team, including first author Yinpeng Zhang, reviewed results from more than three hundred studies and compared different methods for estimating cryptic species. Advances in molecular sequencing have made it easier and cheaper to compare DNA across populations, which allowed researchers to uncover this hidden diversity. The pattern held across fishes, birds, mammals, reptiles, amphibians and other vertebrate groups.
One example is the Arizona mountain kingsnake: molecular data from 2011 showed northern and southern populations were distinct, and the southern group was classified as Lampropeltis knoblochi rather than a subspecies of Lampropeltis pyromelana. The study warns of clear conservation consequences: splitting a widespread species into several reduces each new species’ geographic range, and smaller ranges are generally linked to higher extinction risk. Few cryptic species have been formally described or named, so they often lack legal protection, and hidden diversity can lead managers to mix or breed different species unintentionally.
The research appears in Royal Society Publishing: Proceedings B. Source: University of Arizona.
Difficult words
- synthesis — summary that combines many research results
- cryptic — difficult to see or recognize as distinct
- lineage — group descended from a common ancestor over timelineages
- molecular sequencing — methods to read and compare DNA sequences
- geographic range — area where a species naturally occurs
- extinction — when a species disappears and no individuals remain
- conservation — protecting species and their habitats
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- What problems might arise if managers mix or breed cryptic species by mistake? Give specific examples.
- How could formally describing and naming cryptic species change their legal protection and conservation status?
- What are the benefits and challenges of using molecular sequencing for identifying species in conservation work?
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