What's unclear in the submitted article is whether the slugs have genes evolved by mutation for producing chlorophyll from earlier slug genes or whether the slugs have incorporated algal genes into their own genome--which would be be a bigger deal. Of course the article notes that some scientists don't think that the chlorophyll production is being done by slug genes at all, but by algal genes contaminating the slugs. Interesting research, well worth more follow-up.

How many human beings would like to be able to photosynthesize?