The use of y-dna testing to trace paternal lines stems from the fact that the Y chromosome is inherited solely from the father. Humans have 21 chromosomes that are a mixture of genes from the father and the mother, plus 2 sex chromosomes of type X or Y. Females have two X chromosomes, which also contain a mixture of genes from the father and the mother. Males have one X chromosome, and one Y chromosome which contains only genes from the father (since the mother doesn't have a Y chromosome). Chromosomes are long helical strings of DNA. Genes, of which there are about 30,000 in humans, are particular sections of the dna string forming each chromosome. Genes consist of particular sequences of the base pairs that form the twisted helix of DNA. These sequences vary substantially from person to person, causing the various differences among people, while still being very similar in their basic arrangement since we are all humans.

Since a male's Y chromosome is inherited only from his father, it is in principle passed unchanged from generation to generation. By comparing specific locations on the Y chromosome of 2 men, it is therefore possible in principle to determine if they had a common forefather at any time in the past. The chromosome is not always passed perfectly from generation to generation, however, and mutations (changes) happen occasionally in all genes for various reasons - this is the driving force of evolution. The Y chromosome associated with a particular forefather therefore accumulates changes over time, and the changes are passed on to subsequent generations, with further occasional changes forming more branches. If 2 men had a common forefather in the distant past, their Y chromosomes will show strong similarities, but will not match exactly at every point. The more points (or "markers") used in the comparison, the better are the statistics used to determine the probability that the 2 men had a common forefather within a given number of generations.

In addition to comparing specific points between individual men, large scale comparisons are being made among various ethnic and geographical groups around the world. The Lauperswil Welty line is in "haplogroup I-1c", which is relatively rare and whose common ancestor lived sometime before the last ice age. You can read more about this here: LINK

FTDNA.com is a company that sells DNA testing services. To promote sales (and no doubt for the benefit of mankind, etc. :) they also provide a format for organizing "family name projects", and offer a discount on test services for those who sign up for the projects. Signing up for the project makes your test results available to the administrator.

Detailed results can be found at:

The group administrator's website:

A general discussion of y-DNA testing is here:

Some basic infomation on chromosomes and genes can be found at: