Meet the slug that’s evolving into a leaf

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This green sea slug Elysia chlorotica can survive months without a bite to eat, by photosynthesising. As weird as it sounds, this animal has managed to take on the properties of a leaf. Instead of taking in physical food, this slimy sea dweller can obtain nutrients from the sun.

The algae that usually makes up the sea slug’s diet has become part of its DNA, and the algae’s plant genes have transferred to the slug. This is one of the only cases of gene transfer known to science.

The slug ‘steals’ photosynthesis cells from the algae and uses them for up to nine months. That’s longer than the cells would have lasted in the algae. With these stolen genes, the slug can feed on sunlight when it can’t find any food.

This rapid evolution has amazed the scientific world, including the researchers that made the discovery. The slug’s body itself even looks like a freshly fallen leaf.


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