A team of researchers is the first to provide definitive proof that green algae eat bacteria. The finding, captured with electron microscope images, offers a glimpse at how scientists think early organisms acquired free-living chloroplasts, the structures responsible for converting light into food. This event is thought to be a critical first step in the evolution of photosynthetic algae and land plants, which helped raise oxygen levels in Earth’s atmosphere and paved the way for the rise of animals.
In a paper that appears in the June 17, 2013, issue of Current Biology Eunsoo Kim, an assistant curator in the Museum’s Division of Invertebrate Zoology, and her colleague Shinichiro Mauyama, a postdoctoral researcher at Japan’s National Institute for Basic Biology, identify a mechanism by which a green alga that resembles early ancestors of the group engulfs bacteria. Their work provides conclusive evidence for a process that had been proposed but not definitely shown.
credit: American Museum of Natural History