8 November 2006
GLOSSARY, ETC. LINKS
Start here Ė and if need more help, click on the glossary web site link:
If those donít help, try some of the others below:
http://blairgenealogy.com/dna/dna101.html [Blair] definitions are at end of section
http://www.kerchner.com/glossary.htm [Kerchner] - Kerchner now sells a hard copy glossary
http://www.onelook.com - not limited to DNA - look up any word - this is a great site!
http://www.genome.gov/glossary.cfm - includes a "talking" glossary feature
http://www.weihenstephan.de/~schlind/genglos.html - includes definition of words in the definition
http://www.cstl.nist.gov/biotech/strbase/glossary.htm - another glossary if the above don't help
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Misc. notes - This is not a complete glossary (use the above links)
BGA - BioGraphical Ancestry. DNA test to determine percentages of African, Indo-European, East Asian, and Native American ancestry. (Results example: 98% European, 2% Sub-Saharan African, 0% East Asian, 0% Native American.)
Clade - see Haplogroup
DYS = DNA + Y chromosome + [unique DNA] Segment. DYS numbers are assigned by HUGO (Human Genome Organization).
False Paternal Event, false paternity, non-paternal event, non-paternity event: all these terms refer to a break in the Y chromosome line due to adoption, name change, "extramarital event" (infidelity), child known by other surname (mother's maiden name, stepfather's name), etc.
Haplogroup (clade) usually refers to ancient/deep ancestry, before surnames
Haplotype - the results of the Y DNA test, the markers and their scores [allele values], are called a haplotype. When two or more results are a close match, the haplotype indicates sharing of a common ancestor. The haplotype, is also sometimes referred to as a fingerprint, blueprint, signature, pattern. The numbers are also known as "allele values" and sometimes are referred to as STR numbers.
Locus - A specific location on a chromosome (loci, plural)
LUCA - Last Universal Common Ancestor, another term used for the Last Common Ancestor of all organisms living today (the root of the tree of life). This is not a surname project term - but someone used it in a joke and I didn't know what it meant.
MLE - Most Likely Estimate - used by population geneticists
Maximum Likelihood Estimate - used in BioGraphical Ancestry (BGA) tests.
Modal -The modal value is simply the most often occurring value or set of values in a given distribution of values or set of values. Compare it to the median value which has half of the distribution above it and half below it. The average or mean value is the sum of the values divided by the number of values. The average can be seriously skewed by a few very large or very small values. So, the modal haplotype is just the most frequently occurring haplotype in a set of haplotypes. (This definition is from John T. Nichols, May 2003, GENEALOGY-DNA-L@rootsweb.com; permission granted.)
MRCA - Most Recent Common Ancestor (first abbr. I had to look up)
SNP - single nucleotide polymorphism. SNPs are used by anthropologists to identify deep ancestry (haplogroups or clades). Haplogroups often can be estimated or predicted based on STRs but to be certain a SNP test is required. This information is not useful for contemporary genealogy
Single Nucleotide Polymorphism (SNP) - (pronounced "snip"), a small genetic change or variation that occurs within a DNA sequence when a single nucleotide, such as an A, replaces one of the other three nucleotide letters: C, G, or T; occur so infrequently that they are used to define haplogroups (From glossary in Trace Your Roots With DNA - by Smolenyak and Turner)
STR - short tandem repeat. The "numbers" [allele values] in a DNA test are based on STRs. In a Y chromosome test, they are also referred to as YSTRs.)
Short Tandem Repeat (STR) - a short pattern (often two to five bases in length) repeated a number of times in a row (in tandem); for instance, GATAGATAGATA, three repeats of the GATA sequence; the differences in the STRs at selected markers on the Y chromosome provide a basis for comparison among individuals and populations and are used extensively for most Y-DNA genetealogical testing; also called a microsatellite (From glossary in Trace Your Roots With DNA - by Smolenyak and Turner)
TMRCA - Time to the most recent common ancestor
WAMF -Western Atlantic Modal Haplotype - see Common Haplotypes, etc.