A longstanding question among scientists is whether evolution is predictable. A team of researchers from UC Santa Barbara may have found a preliminary answer. The genetic underpinnings of complex traits in cephalopods may in fact be predictable because they evolved in the same way in two distinct species of squid.
Last, year, UCSB professor Todd Oakley and then-Ph.D. student Sabrina Pankey profiled bioluminescent organs in two species of squid and found that while they evolved separately, they did so in a remarkably similar manner. Their findings are published today in the Proceedings of the National Academy of Science.
Oakley, professor and vice chair of UCSB’s Department of Ecology, Evolution and Marine Biology, and Pankey, now a postdoctoral scholar at the University of New Hampshire, leveraged advances in sequencing technology and cutting-edge genomic tools to test predictability in the evolution of biological light production.
The scientists wanted to know how similar the two species’ photophores are in terms of their genetic makeup. To find the answer, they sequenced all of the genes expressed in these light organs, something that could not be done using older sequencing technology.
“They are much more similar than we expected in terms of their genetic makeup,” Oakley said. “Usually when two complicated organs evolve separately we would expect them to take very different evolutionary paths to arrive where they are today. The unexpectedly similar genetic makeup demonstrates that these two squid species took very similar paths to evolve these traits.”
More specifically, the researchers demonstrated that bioluminescent organs originated repeatedly during squid evolution and then showed that the global gene expression profiles (transcriptomes) underlying those organs are strikingly—even predictably—similar.
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Read full, original article: Scientists show that evolution of complex bioluminescent traits may be predictable
