Definition of "allele" []

• One member of a pair or series of genes that occupy a specific position on a specific chromosome. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Evolution is about one thing: The explanation for the changes in allele frequencies over time."
• "The allele could originate by mutation of an allele for brown fur and the environment caused selection which caused a change in allele frequency."
• "The mechanisms whereby genomes are reduced or expanded are often not the standard "neo-Darwinian processes", ie changes in allele frequency."