Yes Way machnn..Its simple Genatic Mutation..Either we like or not all the creatures in earth are made with basic simple DNA Codon.it is called a "GEnome".In other words a basic DNA Structure..
When creatures having their evoulution, sme DNA Codons hidden..some get Highlighted..For humans all the characteristics are continues becz of those Highlighted codons..
"Codons" means three phases of Nuclic Acids (Adinine.Thaymin,Guwanin,Cytosin or Urasil)..
But that dosent mean all the Hidden DNA Codons are vanished..Somehow those Hidden Codons comes to the action..This happens very rarely..Very very rarely..
This is the "Mutation"..Bcz of those Hidden Codons are weak and UnHighlighted, the Subject became completly differant than the Original..therefore no need to worry..