Cells, Bodies, and Brains

This chapter describes evolution as a long-running algorithm that has designed all species on Earth. Evolution, a process discovered by Charles Darwin, has been working for more than four billion years to obtain, at first, simple unicellular organisms (prokaryotes) and, later, much more complex life forms, based on eukaryotic cells. Evolution worked not with bits stored in a computer memory, but with replicators that are digital sequences written in very long DNA molecules, the genomes. Complex cells, which are the results of this optimization algorithm, eventually organized themselves in vast multi-cellular complexes, leading to the multicellular organisms in existence today and, ultimately, to humans and the human brain, the most complex information processing device we know.