Mitochondria and Chloroplasts

Margulis believes that mitochondria were originally parasites (or predators - the distinction is not important at this level) which attacked the larger bacteria that were destined to provide the shell of the eucaryotic cell. There are still some bacterial parasites that do a similar trick, burrowing through the prey's cell wall, then, when safely inside, sealing up the wall and eating the cell from within. The mitochondrial ancestors, according to the theory, evolved from parasites that kill ...

 Spring Recapitulates Evolution

Spring provides a kind of annual recapitulation of the evolution of life on Earth, an opportunity to celebrate anew the greening of the planet three and a half billion years ago by the first photosynthesizing bacteria. All life—the whole glorious parade along the path—depends upon the photosynthesizers. As spring dresses the deciduous woodlands in its Easter best, the nonphotosynthesizers get moving too. Suddenly the woods are skittering, fluttering, munching. singing. From rock-hard seed...