Scientists reveal how a little-known amoeba engulfed a bacterium to become photosynthetic. About 100 million years ago, a lowly amoeba pulled off a stunning heist, grabbing genes from an unsuspecting bacterium to replace those it had lost.
Now... scientists have solved the mystery of how the little amoeba, Paulinella, committed the theft. It engulfed the bacterium, kept that cell alive and harnessed its genes for photosynthesis, the process plants and algae use to convert carbon dioxide into oxygen and sugar via solar energy.
“The major finding of the study is the microbial world, which we know is full of valuable genes, can move these genes between organisms according to need... When a microbe has a gene deficit, it can in some cases fill that deficit by grabbing the same gene from the environment. This shows how fluid microbial genomes really are”...
The Earth is green because photosynthetic plants and algae contain chlorophyll... Their photosynthetic ability arose from a much more ancient theft committed some 1.5 billion years ago. Back then, an algal ancestor engulfed a photosynthetic bacterium, reducing it to a chloroplast... The engulfing process is known as primary endosymbiosis, and it altered life on Earth by allowing the rise of animals that depend on plant life.
“Evolution can find a way, in this case by solving the problem of broken genes by gathering replacement genes from the environment... Who knows, in a 100 million years or so, the descendants of Paulinella might become the dominant plants on our planet.”