When considering my ancestors, I have sat endless hours online, and in the dusty archives, looking for the concrete evidence, or clues as to where that evidence may lie. Usually we hit walls, and then begin to construct downwards a few generations in hope of some clue to help us get back up the tree further. Why do we do this, to research our pedigree? This all started when a German (or Moravian as German had not been formed then) Augustinian monk called Gregor Mendel (1822-1884) started playing around with sweet peas. His experiments with breeding peas and mice lead to the birth of the idea of heredity.

If we ever find the answer to why we do this madness, we then have to solve the problem of how we show our data to others, and understand it ourselves. We get many of the of the family tree conventions from the world of medicine. Thankfully the classical cross fertilization breeding experiments as performed by Mendel are not allowed in humans - human geneticists are not allowed to selectively breed for the traits they wish to study! Therefore, unable to do experiments, what did develop was pedigree analysis. When human geneticists first began to publish family studies, they used a variety of symbols and conventions. Now there are agreed upon standards for the construction of pedigrees.

On medical studies, males are always represented by square symbols, females with circular symbols. A line drawn between a square and a circle represents a mating of that male and female. Two lines drawn between a square and a circle indicate a consanguineous mating (the two individuals are related, usually second cousins or closer relatives). They always place the square on the left and the circle on the right of the mating line. Generations are connected by a vertical line extending down from the mating line to the next generation. Children of a mating are connected to a horizontal line, called the sibship line, by short vertical lines. The children of a sibship are always listed in order of birth, the oldest being on the left.

These charts get very complicated, so sometimes, to simplify a pedigree only one parent is shown, the other is omitted. This does not signify divine conception; it merely means the parent left out is not from the family being studied. Each generation is numbered to the left of the sibship line with Roman Numerals. Individuals in each generation are numbered sequentially, beginning on the left, with Arabic Numerals. For example, the third individual in the second generation would be identified as individual II-3.

As genealogists, we have adopted this medical system, but have used the double line to indicate a marriage, rather than consanguineous relationships, and the single line for a less formal relationship. To make matters simpler, we use the direct line charts. These are called an Ahnentafel, which is simply German for ancestor (ahnen) table (tafel). Preparing an ahnentafel chart is a very efficient way of organizing your pedigree chart in order to make it quickly understandable by others.

On a standard pedigree chart, each person is assigned a number. These numbers are worth remembering since, if you follow the traditional numbering system, just by looking at a number you can know the relationship of any person on the chart to yourself. You are always 1, your father 2, your mother 3, paternal grandfather 4, paternal grandmother 5, maternal grandfather 6, maternal grandmother 7, patrilineal great grandfather 8, and so on in consecutive fashion.

Using this system, one quickly notices some patterns. First, each new generation has double the number of ancestors of the previous generation. Thus, you have four grandparents, eight great-grandparents, 16 great-great-grandparents and so on. By the 10th generation, you will have completed research on more than 1,000 ancestors; so, in theory, you are related to the following ancestors

Assuming that you have four generations per hundred years, then;
100 years ago, you would have had 16 direct ancestors
200 years ago, you would have 256 direct ancestors
300 years ago, you would have 4,096 direct ancestors
400 years ago, you would have 65,536 direct ancestors
500 years ago, you would have over a million ancestors, 1,048,576 to be exact.

However, I used the word theory, because by the 10th generation, many of your ancestors will be unknown and others will be duplicates because of cousin intermarriage (it is estimated that before 1800 about 40 percent of marriages were between first, second or third cousins).

Some nice features of the Ahnentafel is that every father on your chart will have an even number and every mother will have an odd number that is her husband?s plus one. Traditional pedigree charts usually print four generations to a page so that 16 generations usually take around four pages to display. The beauty of an ahnentafel is that these same 16 generations would fit on one page.

Your Ahnentafel
The ahnentafel takes the numbering system described above and uses it to create a continuous list of ancestors instead of a chart. The format would be as follows:

1. Your name
2. Your father - 3. Your mother
4 - 7. Your grandparents
8 - 15. Your great-grandparents
16-31. Your great great grandparents
32-63. Your great-great-great grandparents

An ahnentafel is particularly useful when you are corresponding with another genealogist in your family because indicating unknown ancestors with a blank space or line will allow them to see immediately where your genealogical research ends and, from the names and dates given, where you might have common ancestry.

Most of the popular genealogy software programs have the ability to print out an ahnentafel. The most popular format for presenting genealogy data is the pedigree chart, but the simple beauty of an ahnentafel will no doubt appeal to many genealogists wanting a quick, simple view of their ancestry. Increasingly, software programs are offering hourglass charts, bow-tie charts and other picturesque and creative arrangements more notable for their novelty than for any intrinsic value. Set against these, the simple format of an ahnentafel and its superior way of organizing information in a numerically ascending lineal format that allows you to immediately identify your relationship to anyone on the chart is difficult to beat. Most software programs identify each person entered with a number or can be configured to do so.
It may help to have a calculator on hand when you get into the 15th and higher generations. A common shorthand trick is to refer to one?s 15th-great-grandfather as ?G15?, but this could be misleading since you have over 16,000 grandfathers in the 15th generation, so let?s simply refer to him by his unique ahnentafel number of 32768. It would require a thick binder to present this many fifteenth generation ancestors in conventional pedigree charts.
While you may add other information to your ancestral ahnentafel listings other than number and name, in the interest of maintaining simplicity any added data should not take a listing beyond one line of data. It may take a while to get used to this numeric way of organizing ancestors, but it is a remarkably efficient system.