Overview: An evolutionary perspective on reading can contribute to understanding dyslexia and other learning disorders. Human beings evolved speech over many thousands of years, but writing and reading are recent inventions, only a few thousand years old. People perform reading by a kludge of processes that evolved for other purposes, with wide variation in component processes across people and languages. Research on brain anatomy and function shows strong localization of spoken language functions, but an evolutionary approach suggests that localization will be much more variable for reading. Also, children process language across many more brain regions than do adults, suggesting that dyslexia in children may involve more brain systems as well. Processes involved in reading vary from lower-level, modality-specific processes such as vision and hearing, to mid-level linguistic processes, to higher-level processes of memory and attention. Spoken language involves a tighter integration across levels than does reading, and reading requires a greater contribution from higher-level processes because of its recent origin. One tool for investigating how these processes develop and function is analysis of brain volume in living humans by the use of modern brain-imaging tools, discussed by Verne Caviness in an essay for this chapter.