For Darvin Martin, remembering his roots goes way beyond keeping Thanksgiving traditions or reminding himself to call his mother. The Lancaster native has degrees in agriculture and chemistry, but an insatiable curiosity and fascination for genetic genealogy.

"This really is amazing," Martin said, flashing a big smile and diving into topics like single nucleotide polymorphisms and Y-chromosome haplogroups with an infectious enthusiasm and childlike delight.

 Martin has traced his own lineage back more than 1,000 years, but for him, the whole genetic picture is far more captivating than the Martin family's one small part in it. Using Lancaster County names as an example, Martin explained that genetics can tell us not simply that all Martins share certain traits with other Martins, but that, "Martins, Yoders and Zimmermans all share a common ancestor in Switzerland about 800 years ago."

"Neat, right?" asked Martin, who works in technical sales for Sotax, a company that makes pharmaceutical- testing equipment.

Anyone interested in genetics, genealogy or just hearing how interested Martin is in them should set aside 8:30 a.m.-4:30 p.m. Saturday, April 21, and attend the Lancaster Family History Conference at Lancaster Host Resort and Conference Center, where Martin will deliver the keynote address. This year's theme is "Deep Roots: Using DNA to Unlock Your Family's Ancient Past," a topic Martin lives and breathes.

The genetic genealogy Martin and the conference focus on relies principally on Y-DNA testing; that is, finding the genetic information encoded solely on the Y chromosome in order to establish a paternal line through the ages.

We're all carrying a blueprint of all the humanity that came before us, complete with genetic mutation time-stamps. Our DNA comes from mom and dad in equal measure, but only fathers and potential fathers have a Y chromosome. Accordingly, this chromosome provides a genetic snapshot of our paternal lineage that allows researchers to determine not just the likelihood that two individuals share a common ancestor, but, theoretically, also the number of generations removed that ancestor is from the common paternal ancestor from which all mankind descends.

(It's important to note that this method of inquiry isn't the only possible one. Mitochondrial DNA comes only from the mother, and researchers are also using it to find our common maternal ancestor.)

 In testing Y-DNA, scientists look for examples of two phenomena, short tandem repeat, or STR, and single nucleotide polymorphism, or SNP. The former indicates more recent mutations while the latter points to ancient traits. Using SNPs, "All the people throughout the world have been sampled genetically, and they fall into 20 haplogroups," Martin said.

 "Haplogroups" describe subsets of people who are very alike genetically. Some SNPs are present in all populations, while others are common to distinct geographic groups. For example, Asians have certain SNPs that Europeans don't.

"Within 20 minutes," Martin said, "we can tell what haplogroup you belong to. But beyond that, there are markers which further distinguish people and can be specific enough to link common members of a family across generations and continents."

Martin's family, for instance.

"With my Martin ancestors," he said, "I can know that they were of Germanic origin, not Roman or Greek or Celtic, based on these SNPs."

Martin likened the transfer of SNPs to Whisper Down the Lane. The message whispered by the first player undergoes many subtle changes as it travels along its path (assuming no prankster mutates the message along the way), often bearing little resemblance to what the last player hears. If we imagine the message as DNA, testing allows scientists to trace all those changes back to a common source.

DNA consists of four amino acids commonly represented as the cluster of letters ATGC (which stand for adenine, thymine, guanine, cytosine, respectively). The arrangement of these amino acid pairs, that is, the 3.3 billion combinations of A-T and G-C, provide the blueprint for each individual. For more than 99.9 percent of people, these pairs are identical. But occasionally when DNA replicates, the arrangement of one of these acids changes, and that change is what researchers can identify as an SNP.

This phenomenon has the benefit of following surnames in a patrilineal culture like ours. "We can determine that, for example, the Burkholders fall into a certain haplogroup because we've had eight or nine of them tested," Martin said. "So if somebody else tests and ends up being closely related to the Burkholders, we can begin to set up this deeper ancestry."

All humans alive today share a common paternal ancestor who lived in east Africa. And while he was hardly the only man alive then, he was the only one whose genes directly live on in all of modern man. Martin framed it this way, "We do have other ancestors, but we don't have other direct paternal ancestors."

Research into this deeper ancestry has lead scientists to develop elaborate models and theories of human migration out of Africa. But the models aren't yet complete, Martin said.

 "Testing more people will make these [migration] paths more specific," he said. "The way I see it, the paths now are general, which is not to say they're wrong, but they're going to become better and better defined." Martin cited being able to tell if a certain group hailed from the north or south side of the Baltic Sea as the kind of specificity science is on the cusp of achieving.

In order for that happen though, more people will need to have their DNA tested. "The number will have to double or triple," Martin said. "We've got about 400,000 people tested now, and as we have more data, we can build a more likely scenario that explains where people came from and how they got there."

Nevertheless, when asked to compare the state of genetic genealogy today to three years ago, Martin didn't hesitate. "We're worlds ahead of where we were," he said, adding that exponential growth in computing power, as well as the accumulation of raw data, "is happening so fast that it's hard to keep up." In the near future, Martin predicts, "we'll be able to get very, very specific" about an individual's geographic lineage. "If not what town they came from than definitely a small region."

To register or for more information, visit lmhs.org, call 393-9745 or email historyconference@lmhs.org.