“For the first time ever, we looked at the evolution of venom across all fishes,” said lead author William Leo Smith, assistant curator at the University of Kansas Biodiversity Institute. “Nobody had attempted to look across all fishes. Nobody had done sharks or included eels. Nobody had looked at them all and included all fishes in an evolutionary tree at the same time.”
According to Smith, the 18 independent evolutions of venom each pose an opportunity for drug makers to derive therapies for a host of human ailments.
“Fish venoms are often super complicated, big molecules that have big impact,” he said. “Venom can have impacts on blood pressure, cause local necrosis, breakdown of tissue and blood, and hemolytic activity — it prevents clotting to spread venom around prey. Venom is a neurotoxin. The average response is incredible pain and swelling.” Paper. (paywall) – W. Leo Smith, Jennifer H. Stern, Matthew G. Girard, Matthew P. Davis. Evolution of Venomous Cartilaginous and Ray-Finned Fishes. Integrative and Comparative Biology, 2016; icw070 DOI: 10.1093/icb/icw070
The fact that these “super complicated” systems evolved eighteen different times pretty much rules out a Darwinian origin (natural selection acting on random mutation). No wonder they are rethinking evolution.
See also: Evolution appears to converge on goals—but in Darwinian terms, is that possible?
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