Genealogy has entered the molecular era. No longer does a researcher need to pour over microfilm readers in dark archives, but now can turn to something he or she has carried from birth, genetic material. In general all humans have 99.5% identical genetic material in their chromosomes. That is an indication that we are not a very old species and also that at various points in our ancient history our species was on the brink of extinction. Most animal species show much more diversity. For example, the fruit fly has about 10 fold more diversity than man. One species that has less than man is the Cheetah. Among human populations that of Africa has the most diversity and this is taken part of the evidence that mankind evolved in Africa. However, it is not the similarities, but the differences among individuals that is useful in genealogical research. Because the genetic code is so long there are still thousands of genetic differences between people. These differences are generally either single-nucleotide polymorphisms (SNPs) or are copy-number variants. Single-nucleotide polymorphisms have a different code element at one point in the code, such as one might see if a combination lock number code was one number off. Copy-number variants (code repeats) are a block of code that is repeated multiple times, such are one might hear when a phonograph needle catches and plays the same series of musical notes over and over.
In the case of males useful differences in genetic material can be found on the Y-chromosomes. A human being has 23 pairs of chromosomes in his cell nucleus. Only one of them is not identical to its mate. This is the Y-chromosome, which in a male is paired with an X-chromosome. Females lack a Y-chromosome and have a pair of X-chromosomes. The Y-chromosome is passed from father to son and thus follows the surname.
There is also another form of unique genetic material, mitochondrial DNA. Although this exists in both males and females, it is only received from the cellular fluid of the ovum (egg) and thus has been passed straight down the maternal lineage. It is useful in broad population studies, but does not follow a surname. It can be used to compare two individuals who are believed to be direct descendants of a common female ancestor. In European counties mitochondrial DNA types have similar frequencies and cannot be given any particular interpretation. Mitochondrial DNA is not found in the nucleus of cells at all and exists in cell organelles (structures that float in the fluid of cells) called mitochondria as a unique form of DNA that actually has slightly different coding from nuclear DNA. These differences support a theory that what is now part of our cells was once a separate organism that started as a parasite in a symbiotic relationship with the cells.
Analyzing Y-chromosomes holds a promise of trying together many of the Lanham lines that so far have not been connected to an immigrant ancestor. DNA studies can look beyond the brick wall that so many genealogists hit with conventional genealogical research. In most cases the Y-chromosome is received from a male's father as an exact copy. Every so many generations the copy is not exact and contains a mutation at a certain location. Some mutations effect critical genes and can be lethal or produce birth defects. However, in most cases they occur in the genetic bubble wrap code between critical genes and cause no obvious problems.
The physical characteristics of a chromosome can be studied by laying it out and looking at certain locations along it. A particular location is called a locus and the variable gene coding at a locus are different alleles of the gene. The DNA code segments used to identify a particular allele are called markers. A particular trick used to make DNA studies practical and affordable is to study areas in which the code is repeated over and over in what are called short tandem repeats (STR). These stand out in the way music does then mixed with background noise. A number can be assigned to the allele based on the number of times the segment repeats itself. There are a mean number of repeats that a sample of males have at each of these loci where STR segment markers occur. For example, in one sample population 82% of males had 13 code repeats at locus DYS# 393. The range of repeats at that locus is between 10 and 17 in different people. By looking at a large number of loci within the Y-chromosome a unique pattern of alleles emerges almost like the numbers of a combination lock.
If you compare the results of two different people who might be related the differences between the series of numbers defines the degree of relationship. This is because every so many generations a mutation occurs that drops or adds a repeating segment changing the number value (allele) for that locus. After this happens the male descendants of that individual will pass that difference down as a distinction of that line. Several Lanhams, including myself, have had Y-chromosome DNA analysis done. The results are very similar but not identical.
There is another type of Y-chromosome DNA analysis which looks at single nucleotide polymorphism (SNP) and defines various human Haplogroups. The pattern of results from this analysis indicates that the sampled Lanhams all belong to the R1b Haplogroup. Human populations around the world have different patterns of Haplogroups. Rib is most commonly found in individuals living in the Great Britain (about 75% of the population) and also Spain (about 66%). It also can be found to a somewhat lesser degree (30-40%) in France, Germany, Italy and Ireland. People from these counties appear different to us in their physical features, but what these genetic results tell us is that the basic stock originated together and then genes that influenced things like skin tone and eye color diverged. The original mutation defining the R1b group is believed to have developed 20,000 years ago in the Caucasus region. It spread westward into Western Europe and Britain. Following waves of migrations by peoples of other Haplogroups diluted it in Asian and Eastern European populations. It is known that during the last ice age northern Europe was basically uninhabitable and a remnant human population survived in Spain. When the last ice age ended and the glaciers receded these people moved northward and repopulated Western Europe. These events occurred long before identifiable historical ethnic groups emerged in Europe.
Haplogroup analysis has occasionally turned up surprising results. For example, studies of living relatives of Thomas Jefferson revealed a K2 Haplogroup pattern. This is most commonly found in individuals living in the Middle-East and Egypt and is rare among people of British background. The original mutation defining the K group is believed to have developed 40,000 years ago. The result caused some to say that Jefferson's male line originated with an individual who was of Jewish or Phoenician background. This is a case of over interpretation. K2 may have been present as a remnant in European populations long before Phoenician traders visited the British Isles or the Jewish Diaspora.
Of course, the Lanham results are no surprise. Most Lanhams claim that their ancestry arose in the British Isles and these results confirm it. They also make it less likely that the origin of the Lanham line came from a Scandinavian county. There was heavy Viking settlement in all the British Isles, but R1b is less common among Scandinavians. However, about a quarter of modern Norwegians have an R1b pattern and the possibility cannot be excluded.
Can we learn more from Y-chromosome analysis about Lanham family relationships? The answer is yes, but at this point in time we only have a limited number of individuals who have been studied. We need more to see if patterns emerge that characterize certain Lanham lines. The cost of doing these tests is over a hundred dollars and involves mailing away a swab taken from the month. There are various vendors who offer the tests. The more markers done the more specific and discriminatory the results, but also the greater the cost.
I should caution any person doing DNA analysis that the results may be surprising. They might show a pattern that is totally dissimilar to other kin and suggestive that somewhere up the paternal line is an ancestor was not who you believe he was. It might let the skeleton out of the closet. Hopefully, a nature person will be able to accept this risk and the knowledge that our ancestors were flesh and blood humans and capable of the human failings not unlike those known to occur in our own time.
