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Sun, Feb

Saving Sharks With Trees: Researchers Aim To Save Key Branches Of Shark And Ray Tree Of Life

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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 the unique evolutionary history they account for.

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 the unique evolutionary history they account for.

“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?” asks 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 their 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. That’s twice the amount for an average mammal and more than four times that for an average bird.

“We were excited to see that the most evolutionarily distinct shark and ray species included a diversity of forms and functions,” says SFU biological sciences professor Nick Dulvy, a senior author of the study. “Everything from deep-water and filter-feeding sharks to electric rays and sawfish rose to the top as being particularly evolutionarily distinct.”

Read more at Simon Fraser University

Photo credit: Jeff Kubina from Columbia, Maryland via Wikimedia Commons