Getting Started in DNA Testing for Genealogy - My Series on Geni.com

For the last month, I have been writing a weekly series on getting started in DNA testing for genealogy for Geni. Just in case you missed it, the articles cover the three types of tests and their applications. The series will be too basic for some of you, but for those of you just starting out, it may be exactly what you need.

Part One, Intro and Y-DNA
Interest in DNA testing for genealogy has reached an all-time high thanks to its increasing sophistication and the resulting visibility in the media. We hear about what we can learn from DNA testing from popular genealogy television programs, news stories and in advertising.  As a result, many family history enthusiasts have expressed their desire to venture into the fascinating world of genetic genealogy, but don’t know where to start.  If you are one of these people, then I am writing this for you. In a series of four posts over the next month, I will explain the three different types of DNA testing currently used by genealogists to discover more about their family trees. I will endeavor to help you determine which test or combination of tests would be best suited to your interests.
Read the rest of the article here.

Part Two, mtDNA
Last week we discussed the Y-DNA test that only traces your direct paternal line back in time, but there’s good news for you women who felt left out. Did you know that there is also a DNA test that traces your direct maternal line back in time?  It is called a mitochondrial DNA (mtDNA) test.
Read the rest of the article here.

Part Three, autosomal DNA (23andMe, Family Finder, AncestryDNA)
This week we are finally going to discuss my favorite type of genetic testing for genealogy – autosomal DNA. For the past two weeks we have covered DNA tests that are solely informative of one ancestral line – direct paternal (Y-DNA) and direct maternal (mtDNA). The great news about autosomal DNA (atDNA) testing is that there is potential to find valuable and meaningful information about any of your ancestral lines.  
Read the rest of the article here.

Part Four, ancestral origin tests and summary
We have covered the three types of DNA tests for genealogy over the last few weeks, but there is one more aspect of genetic genealogy that should not be overlooked. In fact, one of the questions that I am asked most frequently is: How can I get a percentage breakdown of my ethnicity? With popular television programs recently highlighting this compelling area of genetic genealogy, it is no surprise that interest in DNA testing has grown.
Read the rest of the article here.

*Also, don't forget about the $50 off 23andMe tests ending tomorrow at Midnight ! Order here using discount code VMQ6KG.

Y-DNA Testing

Y-DNA refers to the DNA found on the Y Chromosome. It is contained in the cell nucleus of all males. All healthy humans inherit 23 Chromosome Pairs from their parents. The last two are the sex chromosomes, or the X and Y. Only males inherit the Y chromosome, so it can only be used to trace the direct paternal line. Simply speaking, a man inherits his Y chromosome from his father who inherited it from his father who inherited it from his father and so on. Testing of this Y-DNA can reveal the ancient origins of a person's direct paternal line. It can also be of great genealogical value since the Y-DNA traditionally follows the same inheritance pattern as surnames. As the surname is passed down from male to male, so is the Y-DNA. Used in conjunction, a male can often identify which ancestral line he belongs to by matching with others of the same or similar surnames. Though not guaranteed, an adoptee may even find success in discovering his biological surname by testing his Y-DNA. Some testees have not yet found success with this type of testing due to the lack of matches in the databases. However, time should rectify this problem for most with the growing popularity of DNA testing. For cultures that did not utilize surnames in the traditional way until the 20th Century, such as Scandinavia, the Y-DNA can still be useful in identifying probable origins and migration patterns.
Upon testing your Y-DNA you will receive a list of the short tandem repeats (STRs) contained on your Y chromosome that determines your haplotype. You may also be assigned a haplogroup based on single-nucleotide polymorphisms (SNPs) contained in your Y-DNA. Matches are measured by genetic distance (GD) and can estimate the time to the most recent common ancestor (TMRCA) for two males depending on how closely their individual haplotypes match each other.
Y-DNA testing currently available includes both SNP and STR testing. For STRs, a male may order anywhere from 12 markers to over 100 markers. The industry standard is generally 37 or 67 markers at this time. Individual SNPs or panels of SNPs can be ordered to determine and refine one's haplogroup. Scientists and hobbyists are continually discovering new SNPs, this further refining the Y Haplogroups.
For further clarification on the Y Chromosome (for beginners) go to Sorenson's Animations here.