Wonders of Life: Exploring the Most Extraordinary Phenomenon in the Universe (Wonders Series)

by Brian Cox

But how does one cell end up inside another? At some point in the history of life on Earth, a cyanobacterium cell must have been engulfed by another cell and, instead of being digested, it survived to perform a useful purpose. This process, called endosymbiosis, has happened more than once in the history of life on Earth; indeed, it is thought to have been fundamental in the evolution of complex life. Endosymbiosis allows for great leaps in the capability of living things – a merger of fully formed skills to produce a result greater than the sum of the parts. In the case of oxygenic photosynthesis, this particular example of endosymbiosis led to the evolution of two of the great kingdoms of life – the algae and the plants – by allowing machinery evolved over billions of years inside cyanobacteria to be co-opted into more complex multi-cellular organisms.