Darwin Eugene Peek was born on Friday, the 13th of December, 1940, in an ice storm, just after his "parents-to-be" traveled from the family home in Clairemont, Kent County, Texas, to the Callan hospital in Rotan, Fisher County, Texas.

At five years of age, Darwin began his first job, picking cotton during the cotton-picking recesses of the falls of 1946– 1951. He has taught arithmetic and mathematics at Southwest Texas State University (Texas State University) (1965–1966); at Trinity University (1966–1999); and in the Pre-Freshman Engineering Program (PREP) at the University of Texas at San Antonio and at about thirty sites throughout Texas, the nation, and Puerto Rico during the summers of 1985–2003.

Darwin has published several mathematical articles in refereed journals. He holds a patent for an icosahedron puzzle device that is similar to a Rubik's Cube.

Darwin married Patricia Ann Tanner on August 19, 1966. Their children are Peggy Ann Peek, Penny Ann Davis, and David Eugene Peek.

His present wife is the former Willa Mary Dunlap Smith. They live in McKinney, Texas. His stepdaughter is Susan Elizabeth Kempf.

Darwin has eleven grandchildren