| Everyone is related. The term "related" or "relationship" is used
within the context of a "recent" relationship -- i.e. within approximately the
last 1,000 years. This is the period of interest to most genealogists.
Research before that time is made more difficult due to the lack of family
surnames and the absence of records.
DNA evidence is a series of numbers. If two people have matching
numbers, they may be related. The more numbers that match, the more likely
they are to be related. (These numbers are called "markers" or "alleles".
A marker is the position on the DNA chromosome where the change took place, and
the allele is the count of the number of molecules at that position.)
DNA changes very slowly. When and where the changes occur are random.
The odds of one marker changing multiple times is extremely unlikely. For
this reason, we assume certain starting points for a group of people and we assume the markers do not return to a previous value.
A "haplogroup" is a designation given to a large group of people descended from one common, ancient ancestor. A person can be placed into a "haplogroup" based upon his (or her) DNA signature.
For Y-DNA, there are certain very slow-moving markers which can be tested to
confirm the haplogroup a person belongs to. The signature for that
haplogroup is assumed to be the starting point for that person's DNA signature
and any difference from it is assumed to have occurred after the haplogroup
progenitor lived.
The haplogroup for all of the Cloud Project members, at this time, is R1b1,
and most likely R1b1c. The signature for that haplogroup is used as the
starting point for our interpretation of the results.
We look for unique changes from the haplogroup signature to identify certain
branches. Some changes (mutations) may occur within one line and won't be
seen in others. These are "noise" in that they confuse the analysis. In mathematical terms, these are points on the graph which must be ignored because they fall outside the bounds of reasonable data. Having more tests from people in that branch can isolate those mutations and can
indicate when they occurred.
Having good pedigree information of the participants allows us to combine it
with the DNA data to come up with useful DNA signatures and to identify and
isolate the spurious mutations which occurred more recently and which might
otherwise confuse the analysis. |
