Normal DNA sequence variations in humans
Part 2. Genomics
Published Online: 15 JUL 2005
Copyright © 2005 John Wiley & Sons, Ltd
Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics
How to Cite
Kidd, K. K. 2005. Normal DNA sequence variations in humans. Encyclopedia of Genetics, Genomics, Proteomics and Bioinformatics.
- Published Online: 15 JUL 2005
Within the past quarter century, researchers have been able to study variation directly in the human DNA sequence. Though almost all of the human DNA sequence is identical in all humans, the small fraction, less than 1%, that does vary is more than sufficient to make each independently conceived human genetically unique. Many types of normal variation exist, from differences in a single nucleotide to the presence or absence of blocks of DNA hundreds of nucleotides long. The distributions among populations of the variant forms can differ but overall, they are consistent with a pattern of human expansion from an origin in Africa to occupation of all major continents.
- linkage disequilibrium