The evolutionary science field recently gained some insight last week after UCSB researchers discovered evidence that the first vision-related genes appeared in an organism nearly 600 million years ago.
The researchers came to their conclusion after analyzing the genes of the modern Hydra, which is classified as a cnidarian – a class that includes jellyfish and coral. Following this study, UCSB scientists determined Hydras developed light-receptive genes during the Ediacaran Period of the Neoproterozoic Era. The findings were published in a Public Library of Science journal last week.
According to the research, the development of genes called opsins in pre-historic Cnidarians allowed for light sensitivity.
In a press release, UCSB researcher and graduate student David Plachetzki said Hydras and fellow cnidarians offer scientists a glimpse into the evolutionary process.
“Not only are we the first to analyze these vision genes [opsins] in these early animals, but because we don’t find them in earlier evolving animals like sponges, we can put a date on the evolution of light sensitivity in animals,” Plachetzki said.
Researchers now hypothesize that Hydras, which are predators, use the light-sensitivity to attract prey. While Hydras do not have eyes or other light-receptive organs, such opsin proteins are used all over their bodies and particularly near the mouth.
Since cnidarians were among the first creatures to develop beyond sponges, the presence of these genes in modern Hydra allow for a definitive assumption of when organisms first became light sensitive, Platchetzki said.
“Animals evolved a special way of being photosensitive, which was elaborated in vision,” he said.
UCSB professor and fellow researcher Todd Oakley said the discovery provides a new, key component to the ongoing evolution debate. Since the researchers can now estimate when the specific gene developments occurred, Oakley said this knowledge challenges anti-evolutionist arguments that claim genetic mutation cannot create new traits.
“Our paper shows that such claims are simply wrong.” Oakley said. “Slowly we are showing all the steps [of evolutionary development], and this is another important step.”
The scientists conducted the research with the assistance of a National Science Foundation grant and will use the research as the basis for further study in evolution and genetics.