"Y-chromosomal Adam" is a term used in genetics to refer to the most recent common ancestor of all living humans through their paternal line. While this is a widely accepted term, there are other similar terms that can be used to refer to this ancestor. You may also use "Y-MRCA" which stands for "Y chromosomal most recent common ancestor" or "Y-Adam" which stands for "Y-chromosomal ancestor of all men." Additionally, some researchers use the term "SRY Adam" or "SRY-DYF Adam" which refers to the gene called SRY- which is responsible for encoding a protein called Testis-determining factor (TDF) on the Y chromosome. Regardless of terminology used, this ancestor is believed to have lived around 200,000 to 300,000 years ago.