Haplogroup J1, more fully Y DNA haplogroup J-M267, is a Y chromosome haplogroup found in the Middle East. This means it represents a group of descendants from a single common ancestor along the father's line. It carries a mutation on the Y chromosome known as M267. This type of mutation is called a SNP, or a single nucleotide polymorphism, which is a change in the chemicals at one position in a gene's DNA. Y chromosomes are passed down from father to son without changing, so an SNP like this shows common ancestry.
The origin of this mutation was between 4,000 and 24,000 years ago.
This mutation followed a previous mutation, which created the haplogroup known as haplogroup J-P209 or simply haplogroup J, and so this makes this Y chromosome the "child" of the older version of the Y chromosome. Haplogroup J arose from a mutation which occurred about 31,700 years ago in Southwest Asia.