One individual absorbing the powers of another seems like the kind of thing that only happens in comics or video games. But allow Mother Nature to surprise you once more. A sea slug found mostly along the United States’ east coast has the strange and life-sustaining ability to steal photosynthetic genes from algae. The bright green slug, scientifically called the Elysia chlorotica, is truly an unusual organism that survives by eating algae and at the same time, stealing the algae’s ability to feed off of sunlight. In short, the slug can survive by eating like humans would, but can also sustain itself using sunlight just like plants.
While the photosynthesizing sea slug has been known to do its “power-stealing” act since researchers confirmed it in the ’70s, not much has been known as to how or why such a phenomenon works until now. Apparently, what the slug steals are the chloroplasts from the alga Vaucheria litorea, which are organelles that essentially process light into food. In a method called kleptoplasty, the slug eats the algae but are only partially digested, with the chloroplasts lining the slug’s digestive tract. The chloroplast-lined stomach is able to then photosynthesize for up to nine months, and produce carbohydrates and lipids for the slug.
How does it do that exactly? Using advanced DNA imaging techniques, a study that appears in the Biological Bulletin published on December 1, 2014 reveals that the slug is able to do so because it has incorporated the algae’s genes that code for both chloroplast proteins and chlorophyll synthesis. Translation: the slug has become one with the algae.
If it sounds improbable, the study’s head, Sidney Pierce from the University of South Florida states that it really is: “There is no way on earth that genes from an alga should work inside an animal cell. And yet here, they do. They allow the animal to rely on sunshine for its nutrition.”
The study confirmed that the genes necessary to repair damage to the chloroplasts and sustain them inside the slug are present in the slug’s DNA. Even more remarkable is the fact that this DNA information is transferred to the next generation of slugs–although the slug must still steal chloroplasts from new algae.
In this remarkable example of rapid biological evolution, the sea slug demonstrates a truly one-of-a-kind ability to advance its own evolutionary process faster by 1000 years with its ability to absorb genes from another.