This tutorial is Part 2 of a 9 part series.
Part 1, What is Y-DNA?
Part 2, Types of Ancestral Markers in Y-DNA <<== You are here
Part 3, STR Markers in Y-DNA
Part 4, STR Markers in Y-DNA - Y-DNA STR Marker Testing
Part 5, STR Markers in Y-DNA - What is Genetic Distance?
Part 6, STR Markers in Y-DNA - What is the Time to Most Recent Common Ancestor (TMRCA)?
Part 7, STR Markers in Y-DNA - Why test more STR markers?
Part 8, SNP Markers in Y-DNA - Y-DNA Haplogroup and Subclade Determination
Part 9, SNP Markers in Y-DNA - Summary of Y-DNA Test Types
The Y-DNA has two very different types of markers which are useful for tracing Paternal ancestry: 1) STR markers and 2) SNP markers.
1. Y-DNA STR Markers
STR stands for "Short Tandem Repeat". STR markers have a very fast mutation rate (approximately one mutation every 20 generations). The rapid muation rate of Y-DNA STR markers makes this marker type useful for confirming recent family connections (within dozens of generations).
Y-DNA STR markers can be used to determine whether any two male individuals share the same paternal lineage. If a match is found, calculations can be performed to see how many generations ago the two male individuals most likely shared the same paternal ancestor. Males who have very different Y-DNA STR marker profiles definitely do not have the same paternal lineage.
We will discuss Y-DNA STR markers in greater detail later in this tutorial.
2. Y-DNA SNP Markers
Unlike STR markers, which have a very rapid mutation rate, a different type of marker found in Y-DNA called "SNP" markers have a very slow mutation rate (approximately one mutation every few thousand years). SNP stands for "Single Nucleotide Polymorphism". SNP markers are used for tracing deep ancestry (ancient ancestry from tens of thousands of years ago). Y-DNA SNP marker testing will allow you to determine which Y-DNA haplogroup you belong to. Haplogroups are ancient family groups which can be traced back to ancient origins in Africa over 100,000 years ago. Y-DNA SNP markers are strictly for studying ancient ancestry (haplogroups and subclades) and do not carry any information pertaining to recent ancestry (recent ancestry refers to ancestral events within the past few hundred years). We will discuss Y-DNA SNP markers and haplogroups in more detail later in this tutorial.