HomeDNAThe Gilliland Thriller – The DNA Geek

The Gilliland Thriller – The DNA Geek

Household legend holds that younger John was hidden in a nicely when Indians attacked.  His mother and father died within the skirmish, and John was raised by an adoptive household.  Whether or not the Hamilton surname was that of his organic mother and father or his adoptive ones is unknown.  We don’t even know if the story is true.

John Hamilton was born someday between 1860 and 1865, in response to varied sources.  He reported that he was born in Texas, however there are not any up to date paperwork to corroborate that.  The primary confirmed file of John Hamilton is that of his marriage to Mary Rowan Smith in 1888 in Conway County, Arkansas.  He and Mary farmed and raised their household in close by Yell County, Arkansas.  He died there in 1937.

John’s nice grandson Gary has been making an attempt to determine John’s organic mother and father for a number of years.


DNA Testing Technique

Autosomal DNA (atDNA) represents all branches of your tree, however it will get “diluted” with every era.  As a terrific grandchild, Gary inherited solely about 12.5% of John Hamilton’s autosomal DNA.  His finest technique to determine John’s mother and father, due to this fact, is to check a number of descendants of John.  There are two causes to do that.  First, identified cousins can be utilized to eradicate shared matches on Gary’s maternal and grandmaternal strains in order that we are able to give attention to those that are associated by way of John.

Second, these different descendants would possibly characterize parts of John’s genome that Gary didn’t inherit.  One of the simplest ways to visualise that is utilizing the Protection Estimator at DNA Painter.

The 9 DNA testers proven in black within the diagram characterize roughly 52% of John’s DNA.  That’s, these 9 kits might conceivably determine about half of the individuals John would have matched had he examined himself.  In apply, we solely have direct entry to 5 of those kits.  All 9 can be utilized to kind matches, however our entry solely represents about 41% of John’s genome.

Not like autosomal DNA, the Y chromosome is handed undiluted from father to son.  Occasional modifications (mutations) can be utilized to gauge what number of generations separate males whose Y-DNA matches.  Gary and two of his first cousins, SLH and JLH, have finished the Y-111 take a look at at FamilyTreeDNA, and two of the three have finished the Large Y-700 take a look at.  They’re all direct male-line descendants of John Hamilton and match each other as anticipated with each atDNA and Y-DNA.  Nonetheless, they don’t match another Hamiltons; the vast majority of their prime Y-DNA matches have some variant of the surname Gilliland (e.g., Gililland, Gilleland, Gillan, and Gilland).

Apart from each other, their prime Gilliland matches on the 111-marker degree are PG, MG (each actual matches), DG (3 variations), LG (4 variations) and CG (6 variations).  Solely PG shares atDNA with any of the Hamilton descendants.



DNA and/or census proof prompt six hypotheses.  Not all are mutually unique.

  • Speculation 1:  Our John Hamilton is the 17-year-old John Hamilton censused in Cooke County, Texas, in 1880.  He was single, a lodger, and dealing as a porter in a saloon.  That is the one John Hamilton in that census who was born in Texas, of the proper age to be our John Hamilton, and never residing with household.  No DNA proof has been discovered to both assist or refute this speculation.
  • Speculation 2:  Our John Hamilton was the identical individual as John Gilliland (born circa 1861), son of John R. Gilliland (c.1831–c.1865) and his second spouse Charity Wilke, from Van Zandt County, Texas.  The elder John Gilliland died in 1864 or 1865, which partially aligns with the orphan story.  The son was censused together with his mom in 1870 however not in 1880.  May he be the John Hamilton of Speculation 1?  If this speculation have been true, Gary can be a junior third cousin as soon as eliminated to DG, who matches on 108 of 111 Y-DNA markers.  FamilyTreeDNA provides this match solely a 44–60% probability of being throughout the final 4–5 generations, and DG doesn’t share atDNA with the identified Hamilton descendants, so this speculation appears unlikely a priori.

  • Speculation 3:  Our John Hamilton was a son of Joseph Gilliland (1816–1873) of Tennessee.  This speculation is supported by an actual Y-DNA match at 111 markers to MG.  If this speculation is true, MG can be a junior third cousin as soon as eliminated to Gary.  FamilyTreeDNA estimates a 98% probability that the connection is inside 5 generations.  Nonetheless, MG doesn’t share atDNA with the Hamilton descendants, and all of Joseph Gilliland’s identified sons may be traced.  None was sufficiently old to have been our John Hamilton’s father.
  • Speculation 4:  Our John Hamilton was the grandson of Thomas Gilliland (≈1782–1852) and his spouse Mary Ann Galliher (b ≈1790) from South Carolina.  This speculation is supported by an actual Y-DNA match at 111 markers to PG.  If this speculation is true, Gary and PG are 4th cousins.  PG shares atDNA with Gary’s sister (36 cM in a single section) and his two first cousins (23 and 37 cM, respectively; one section every) however not with Gary or his Hamilton second cousins. FamilyTreeDNA estimates a 98% probability that the connection is inside 5 generations, and we count on about half of 4th cousins to not share atDNA, so the DNA proof helps this speculation. Nonetheless, none of Thomas Gilliland’s sons are identified to have lived in Texas, the place John stated he was born, or Arkansas, the place John lived later in life.
  • Speculation 5:  Our John Hamilton was the 14-year-old John Hamilton censused in the township of Texas in Craighead County, Arkansas, in 1880.  He’s listed because the son of Charles Hamilton and his spouse Jane.  They might have been solely 17 and 16, respectively, when John was born, and their subsequent oldest baby was 8 years youthful than him.  The identical couple have been censused as presumed newlyweds in 1870 with no kids, though John would have been at the very least 5 years previous on the time.  Is that this our John together with his adoptive mother and father in 1880?  When he stated he was born in Texas, was he referring to the township and never the state?
  • Speculation 6:  Our John Hamilton was another person fully.

Large-Y Time Tree

FamilyTreeDNA not too long ago launched their new Uncover™ instruments for the Large Y take a look at.  My favourite is the Time Tree, a graphical illustration of the time to most up-to-date widespread ancestor (TMRCA) between the lads within the tree.  And it’s actually, actually cool!

The Time Tree is predicated on what’s known as a “molecular clock.”  In essence, it estimates how incessantly SNP and STR modifications have occurred per era all through historical past, then calculates how lengthy it’s been since pairs of males within the tree shared an ancestor.  As a result of DNA mutation is random, there’s essentially numerous uncertainty in these estimates.  Thankfully, we are able to quantify that uncertainty and work with it.  (As an apart, I coauthored a e book chapter utilizing molecular clock strategies for bees, ants, and wasps.)

That is a part of Gary’s Time Tree:

The primary department level, on the higher left, is labeled with the SNP mutation (R-FGC64966) that each one seven of the descendants share.  That node occurred someday between about 600 and 1300 CE (the dashed horizontal line) with a mean across the yr 1000 CE.  Clearly, that’s too far again to be related to Gary’s venture, so we are able to ignore it.

The opposite nodes are much more attention-grabbing.  The one in pink (R-BY94024) represents Gary and his cousin SLH’s shared grandfather, who was born in 1897.  The Time Tree common for his or her grandfather’s delivery is 1876, not far off from the reality.

In the event you go to the “scientific particulars,” you’ll see a chance curve for this estimate.  Time is on the X-axis and probability on the Y-axis.  The upper the curve, the extra possible that date is for Grandpa Hamilton’s delivery.  The black vertical bar marks the common at 1876.  What’s much more spectacular is that the very best level of the curve, known as the mode and marked with the pink arrow, is round 1895.  That is remarkably correct!

To handle Gary’s query, we’re most within the node labeled R-FGC64969.  That’s when Gary shared an ancestor with PG and MG.  Time Tree provides a mean delivery yr of 1643 for that man, with a 95% probability that he was born between 1462 and 1775.  The mode is correct round 1650 CE.

That estimate is each disappointing and helpful.  It’s disappointing as a result of 1650 is way too way back to assist us determine John Hamilton’s father.  It’s helpful as a result of it guidelines out Hypotheses 3 and 4 (which have been primarily based on Y-DNA matches to MG and PG).

By logical extension, we are able to additionally rule out Speculation 2, which is predicated on the match to DG, although DG hasn’t finished the Large Y take a look at and isn’t within the Time Tree.  I say that as a result of MG and PG are actual STR matches to Gary at 111 markers and DG isn’t (they match on 108 of 111 markers).  If Gary’s shared ancestor with MG and PG was born within the 1600s, his shared ancestor with DG is sort of actually additional again.

If the Time Tree is correct (and I think it’s not far off), we’ve been chasing a pink herring with these atDNA segments shared by PG and the Hamiltons.  These segments might have been inherited by way of the Hamilton’s grandmother or nice grandmother; they’re not going by way of the Gilliland patriline.

Lastly, now we have to think about the likelihood that John’s father’s surname was neither Hamilton nor Gilliland.  Assuming a mean era time of 35 years, there have been six generations between John’s delivery and that of the 1650 ancestor.  The surname might have disassociated with the Y chromosome in any one among them.  That isn’t a contented thought.


A Reevaluation

Whereas this outcome isn’t what we’d hoped for, it helps us redirect our efforts.  For now, I’m trying intently at Speculation 5, that our John Hamilton was the boy censused in Texas Township, Arkansas.  This makes much more sense from a geographic perspective than him being the porter in Cooke County, Texas.

Think about this map.  The pink factors characterize the 2 John Hamilton’s within the 1880 census.  The blue factors are the identified places of occasions in our John Hamilton’s life.  The 1800s within the US have been characterised by a gradual migration westward.  If the younger John in Cooke County, Texas, wished to farm, he would gone west for cheaper land, not east.  The John in Texas Township, Arkansas, alternatively, is more likely to have moved westward searching for his personal property.


We nonetheless don’t know who John Hamilton’s mother and father have been.  One complication is that we’ve but to discover a cluster of atDNA matches that would characterize them.  The entire atDNA matches examined to date group with identified lineages of the Hamilton tree.  That in itself could also be informative; it might be telling us that John Hamilton was associated to his spouse’s household by some means.  That might not be uncommon in farming communities of that point.

Gary is happy to see if any new clues about John’s ancestry present up within the feedback about this story.  Do you’ve gotten Gilliland ancestors?  Please chime in!



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