Vélez-Zuazo adds that most of the debate centres on two of the eight living orders of sharks and rays. “The main challenge for resolving the phylogeny for sharks remains the limited amount of data,” she says.

But both groups agree that having a proper phylogeny of these animals is invaluable.

“For an ancient and diverse group like sharks, having a comprehensive phylogeny — meaning including the majority of the more than 500 recognized species — will refine our current understanding of fundamental aspects about the evolution of life history traits of these animals, as well as bony fishes,” says Vélez-Zuazo.

This article is reproduced with permission from the magazine Nature. The article was first published on June 25, 2012.

4 Comments

1. 1. David Russell 01:36 AM 6/26/12

   I am sure that we have missed a logarithmic amount just in the so called industrial age. As a race if it can eat us or compete with us, we genocide it. It is amazing we are starting to put the brakes on and taking time to learn before burn.

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2. 2. Alenz 07:42 PM 6/26/12

   Don't tell this to Shark-eaters!

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3. 3. David Russell in reply to Alenz 09:53 PM 6/26/12

   Most shark eaters eat the fins. Means they catch the shark, cut off all the fins and throw the sharks back into the ocean. So far all the sharks are witches, they drowned.

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4. 4. Ed Greding 01:04 AM 6/29/12

   I would like to know the basis for the genetic analysis and conclusions. How are two or more species separated taxonomicaly using a molecular basis. That is, which specific genes are involved in the separation, and how are these sequences separated from the individual gene sequences that represent intraspecific variation but not interspecific difference? How does one know which nucleotide sequences to apply? How did the investigators decide the number of gene differences necessary to constitute a species? In the cited study, was the entire genome sequenced for each included individual(unlikely),or only part of the genome? Which part? Why? The only way I can see to answer these questions is to read the original paper (to which many have no ready access), and even then one would have to assume that the answers to these questions are incorporated into the paper. Perhaps this article should have included a more detailed part of this megthodology. As it is written in this essay, details of methods and criteria are not even mentioned.

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