What does a Y-DNA test show?

The result is a string of 37 numbers, and contains no personal information.

Y-DNA testing relies on the fact that a small portion on the Y chromosome, found only in males, is passed from father to son,usually unchanged. Amongst this DNA are found several places (called markers)where the DNA sequence repeats between about 8-22 times and this number is characteristic of your all-male descents.By testing this section of 'Junk DNA',you can determine if two men are related.

The number merely shows the number of DNA repeats at each of the 37 markers.

The number of repeats does mutate(change) slowly over long periods of time, so that over the entire period of human history,different families have different marker patterns, but these patterns are mainly stable over the relative short period of time when we have used surnames, that is about 500years.

By using 37 markers, tests also include some markers that mutate slightly faster than the 12 markers and this can sometimes help identify individual branches within a connected set of families.

What personal information does the Y-DNA test reveal?

It is important to understand that genealogical Y-DNA testing is quite different from the sort of DNA information contained in Medical DNA tests that doctors might use to prove paternity or investigate inherited conditions.  DNA tests that police might use to identify criminals is also quite different. Genealogical DNA tests are not useful in either of these two circumstances.

A Y-DNA test does not uniquely identify you, since your father, brothers and uncles will in all probability have identical results(so it's not worth testing very close relations, except in very specific situations), but it will show what other families share the same ancestry.

Can I be identified by Y-DNA?

No. The DNA test provides two results. One is a set of 37 numbers, your haplotype. You share this set of numbers with all your male Hollow ancestors.There will be many other Hollows with the same haplotype. Therefore identifying one person by his Y-DNA is impossible.

The other bit of information from your test is your haplogroup. This is given as R1b1a2or I2a or something similar. Haplogroups are the major branches on the human paternal family tree and are used to trace the human migrations out of Africa to the rest of the world. They are used to study a very broader history of humans. There will be 100s of thousands, perhaps millions, of people with the same haplotype. Once again, not able to be used to trace an individual.

What is a haplotype?

A haplotype is the set of numbers provided by your Y-DNA test. People who share the same haplotype have a common ancestor.

What is a haplogroup?

Haplogroups are the major branches on the human paternal family tree. This is given as R1b1a2 or I2a or something similar. Each haplogroup has many subbranches. These are sub-clades. Haplogroups and their sub-clades(branches)mark human migrations. Thus, learning about haplogroups can tell you about your ancestors' history and travels but their travels before recorded history i.e. some thousands of years ago.

Will my complete genetic profile be determined?

No. This test only looks at Y-DNA, the type of DNA that is used for genealogical testing. This particular type of DNA is found on the Y chromosome, which is found only in males and is passed from father to son.

Y-DNA is found on areas on the Y chromosome called “junk DNA.”  “Junk DNA” carries no information regarding a person’s health, traits, and does not contain markers that could possibly identify any specific inherited condition.

This type of DNA is slow to mutate, so it is excellent to determine ancestries generations deep. This helps surname studies place a particular lineage correctly within a context of a complete genetic family.

What if I find out that my markers don’t match others in the HOLLOW clan?

With any genetic test, you may find that you don’t match others in a family.With a Y-DNA test, this is less traumatic than other types of DNA testing. A mismatch may only mean that an illegitimate birth, adoption, or other non-paternal event occurred in the lineage in the past – it may even have occurred centuries in the past. This may also indicate that you descend from an entirely unrelated line that has the same surname but different origins. It does not indicate that you are not related to your family and it does not mean you are not a HOLLOW;it only confirms you are a HOLLOW with a different Y-DNA haplotype/haplogroup.

Why do you need to collect as many samples as possible?

The greater number of participants adds validity to the study. A wide net that is spread over descendants across the world will also lend credence to this study. We would like to have representatives from the UK, Canada, the US,Australia, New Zealand, and any other country where HOLLOWs, HALLOs, HALLOWs,HOLLAs or HOLLAHs live.

Can women participate?

Yes women can participate, but only males can provide the required DNA sample (because only males carry a Y-chromosome). Female HOLLOWs who want to participate will have to get an appropriate male relative (such as a father,brother, nephew,uncle, etc.) to donate a cheek swab of DNA.

It's actually fairly common for women to participate in projects such as ours (often a sister or wife is the family genealogist, while a brother or husband is the DNA provider).

What about people who are not Hollows themselves but have Hollow ancestors or relatives?

It depends how this came about. There are some instances where a Hollow changed his surname to a different surname. Males in such a line would still carry the Hollow DNA and would be welcome to participate in the project. This is an instance when the partnership between the DNA study and the traditional genealogy study is important. This would be described as a non-paternal event(see later).

In other cases if you are not a Hollow by birth, but you have some Hollow ancestors or relatives, you would have to locate a living male Hollow to provide a DNA sample.

What if I or my father (or other ancestor) was adopted?

All people with the name HOLLOW or its variants are most welcome to participate in the Hollow DNA Project. If the adoption was generations ago then there may be hundreds of descendants carrying the Hollow name. It is important that this is documented through both genealogical studies and in a DNA project.I think it is similarly important if it is the first generation of an adoption as future generations will want to investigate their origins just as we are doing it today.

What are non-paternal events?

The term non-paternal event has come to refer to any instance in which a male child ended up with a surname that is different than his biological father's surname.

Such events most frequently occurred as the result of adoption or instances in which a son took his mother's surname. If a boy's mother was recently widowed, it could also be that the newborn son might take the surname of his mother's next husband (i.e., the boy's step-father). In some cases, grown men have been known to change their surname. There is an instance in the HOLLOW family where the name was changed to a stage name and it has been retained.Also in the past surnames have been changed as a condition of receiving an inheritance from their wives' relatives. Finally, infidelity may also be a factor.

However a non-paternal might have event occurred, the consequence is that some living members of the HOLLOW family actually carry a Y-chromosome that at some point in the past belonged to some other family name. Similarly, there are men out there today whose surname is not HOLLOW, but who carry a Y-chromosome that originally came from a HOLLOW forefather. People in either situation are welcome to join our project.

What if my great-great grandfather was illegitimate and he took his mother’s surname, which was HOLLOW?

This is another example of a non-paternal event and males from these families are very welcome to participate in the Hollow DNA project.

What’s in it for me?

The only thing we can offer is knowledge and the satisfaction that you contributed to a greater knowledge about your/our family. This is especially helpful if your generation is the final generation of HOLLOW males in your line.

This information is important now but also in the future when new generations of family historians pop up wanting to know more about their ancestry. We know to our regret that when information is not recorded somewhere it is very difficult, sometimes impossible to reconstruct the full story.