A representative fully resolved tree containing all 1,192 species of sharks, rays, and chimaeras. Coloured branches represent ED (Myr).

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Saving sharks: SFU study identifies conservation priorities based on evolutionary history

January 18, 2018
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To shine light on, and conserve, rare shark, ray and chimaera species (chondrichthyans), SFU researchers have developed a fully resolved family tree and ranked every species according to its unique evolutionary history.

“While we’ve all heard of white sharks and manta rays, how many of us have heard of the Colclough’s shark or the sharkray?” says Christopher Mull, an SFU postdoctoral fellow and one of the study’s lead authors.

“Most shark and ray species are underappreciated because they aren’t featured in the popular media, but they often play important biological, sociological, or economic roles and deserve conservation attention.”

By quantifying how much unique evolutionary history a species accounts for (also known as its evolutionary distinctness), the researchers discovered that the extinction of a single shark or ray species would prune an average of 26 million years of distinct evolutionary history from the shark and ray tree of life, twice the amount for an average mammal and more than four times that for an average bird.

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