How long is a generation?

kw: analysis, genealogy, history

Many years ago I noticed that when I drew out my family tree as I knew it then, there was a distinct skew. My father had an ancestor on the Mayflower, who was born just before 1600, in the 13th generation (counting myself as Generation Zero). My mother had an ancestor from Nantucket, whose forebear came to the New World in 1626 on one of the later "fleets", who was born in 1608, but was in the 10th generation. This made the tree longer on my father's side, to reach approximately to the year 1600.

Recently someone asked how many generations there are in a century, another way of asking how many years there are in a "typical" generation. I decided to look into it in my own pedigree. I scouted all the ancestors born between 1590 and 1610 (nearly all were immigrants, and of course, for those who were not, their child or children immigrated). I found 13 on my father's side and 13 on my mother's side. I determined their generation. They are all in generation 10, 11, 12, or 13. I also found an ancestor, born in 1628, in generation 9 (nearly all of that generation were born from the 1640s to the 1660s).

I have three brothers, and the average of our birth years is 1952. Of the 13 paternal ancestors scouted, the average birth year was 1603, and for the 13 maternal ancestors it was 1601. I suppose I could have found averages for each generation, but we'll see that this is sufficiently accurate. The year spans of either 349 or 351 years, divided by the number of generations, produced these results:

• On my father's side, 349 divided by 10, 11, 12 and 13 yield 34.9, 31.7, 29 and 26.8 years per generation. The grand average is 31.1 years.
• On my mother's side, 351 divided by 10, 11, and 12 yield 35.1, 31.9 and 29.25 years per generation. The grand average is 32.8 years. Also, that one maternal ancestor born in 1628, in generation 9, leads to a figure of 36 years per generation (this one is not counted in the average).

The overall range of between 26.8 and 36.0 can now be treated as the 2-sigma limits of a normal distribution, centered on about 32 years, with an approximate standard deviation of 2.3. Turning this into a 3-sigma range, I conclude:

For European immigrants to the New World, a generation for them and their descendants, averaged over 10 generations or so, is 32 years, plus or minus 7 (25-39). This ought to cover 997 out of 1000 cases.

It will be interesting to see if I hear from avid genealogists who have 10+ generation cases outside this range. Of course, single generations will be more variable, ranging from 12 to about 50. My wife and I were both just over 40 when our son was born, for example, while the ages of my brothers and their wives when their children were born range from 25 to 35.

Not much king left

kw: genealogy, analysis

Caucasian Americans have a fascination with European royalty, and I am no exception. In my own genealogical studies I find it interesting that I am descended through at least three lines, and possibly four, from either Edward I or Henry III. The two of them, father and son, are descended from Charlemagne, sixteen generations back from Edward, who is twenty-two generations back from me via one of the lines.

I began to wonder, just how much of Edward or Charlemagne, or anyone else for that matter, remains in my genetics, this many generations removed? For I have half my father's genes, and half my mother's (plus or minus some statistical variation), one quarter of each grandparent, and so forth. How much of my genome is likely to be descended directly from an ancestor 22 or 38 generations removed?

Ignoring minor variations caused by descent via a male versus a female line, the process of assortment during meiosis, that produces eggs and sperm, is rather blocky and imprecise, and determines what gets included in a particular gamete. There are three figures of interest here:

• The total human genome consists of 3.2 billion base pairs for a woman, 3.1 billion for a man (the Y chromosome is shorter than the X).
• The coding portion of the genome is just under 1.5%, or about 48 million base pairs.
• There are 25,000 or fewer protein-producing genes.

Now I can pick a few ancestors and see how much "influence" each one has on my genetics.

• John Kirkman and his wife Mary Boyd were immigrants from Ireland. They are four generations removed from me. The factor I'll call Descendancy Fraction (DF) is 2^-4, or 1/16, or 0.0625. Genes are usually not chopped during assortment, so 25,000/16, or about 1,560 genes, came to me direct from each of them. Of coding base pairs, I have 3 million from each, and of total base pairs, about 190 million.
• In the twelfth generation I find Peregrine White, the child born aboard the Mayflower in Plymouth Harbor, and his wife Sarah Bassett. The DF here is 2^-12 = 1/4096 = 0.000244… The amounts I have from either of them amounts to just six genes—or enough fragments to make up six—, 11,700 coding base pairs, and about 780,000 total base pairs.
• Edward I and his wife Eleanor of Castile, 22 generations back: DF = 2^-22 = 1/4,194,304 = 2.384x10^-7. Here the number of genes is less than one: 25,000/4 million means there is 1 chance in 160 that any of Edward's genes has found its way to me. Coding base pairs? Eleven (plus or minus one or two). Total base pairs: about 760.
• Now for the real fun: Charlemagne, 38 generations back. DF = 1/2.75x10¹¹ = 3.64x10^-12. Here we'll just check total base pairs, and it comes to one chance in 86 that even one base pair from any part of Charlemagne's genome has made its way into mine!

I find that amusing. When my mother was a member of a genealogy club, and our probable connection to Charlemagne was discovered, everyone was so thrilled. If genes have anything to do with who we are, however, there is little chance that such remote ancestors shape any part of what we are. It is still true: you are what you make of yourself.

Now, briefly, let's turn the calculation around. I have one child. A friend of mine is one of fourteen children (he has only one child). Each child bears half the genetic component of each parent. But the assortment process is quite random, so that if you have two children, there is a 75% chance of any particular gene, or any particular bit of your genome, being passed into the next generation. The more children you have, the higher the percentage goes.

For both my friend and myself, half our genes have been sent into our offspring. But for his parents, it is a different story. The DF works in this direction, to calculate the fraction not passed forward. His father's DF, for fourteen children, is 1/16,384 or 0.000061… That means that, at most, one or two of his 25,000 genes was not reproduced into his children. The same for his wife. You can say that everything they are has been sent forward a generation. My friend's portion of his parents' genetics is, however, only 50% passed forward, but of course nearly all his siblings have one child or more, so a large proportion of the legacy of their parents lives on. Having children is still the most reliable way to have an impact on the future.

Do I shorten the branch?

kw: genealogy

You'll need to click on this image to see the 1200-pixel original, to make any sense of this. It is a clip from the Ancestry.com display of my family tree.


This shows four generations of ancestors of one Lydia Lamb, a great-great grandmother of mine, followed by four generations of ancestors of Dorcas Gayer, a great-great grandmother of hers—that is eight generations back from myself—and back to Dorcas Gayer's great-great grandfather Thomas Gayer, another four generations, which is twelve generations removed from me, and in ten more generations we reach Edward I Plantagenet, King of England.

The central figure in this diagram is William Gayer, Dorcas's father. A good many descendants of these Nantucketers claim Humphrey Gayer and Jane Sparks as William's parents. Their ancestry is well attested. It is known that they had a son William, but there is some controversy over whether this is the right William. There are two other William Gayers mentioned in documents of the middle to late 1600s, and some contend that one of them is the real father of Dorcas, while others say that the William Gayer, son of Humphrey, is further unknown and the antecendents of all other William Gayers are unknown. Makes life interesting.

The current evidence is, I'll admit, quite circumstantial. It is likely to remain so. This is one of four links in my family tree to English royalty of the 13^th and 14^th Centuries, and the only one that I can't pin down with certainty. But I do like to retain a link to Ed the First if I can. His engineers produced the first large-scale trebuchet, a weight-driven siege engine. Named War Wolf, it reduced several castles in Wales in wars to solidify the English claims therein. That makes Edward a bit of a bully, but I am quite fond of trebuchets. I've built a few smaller ones, including one that throws a golf practice ball no more than twenty feet. I have used it in a few speeches about the history of warfare.

As for William Gayer? I have a note in my tree that this branch may stop with him. For the nonce, I'll leave it at that. There is always a chance that letters between him and his parents will be found, clearing up the mystery.

Turn over a rock and...

kw: genealogy, writing

For the first time since writing a dissertation, I spent the whole day writing. I was composing mini-biographies of selected ancestors, going into the production of a book-length document. In most cases, once I got into each person's records, there was a conundrum or two to solve. In one case, a few sources indicated a certain wife and mother, but the dates were funny: she was 20 years older than her purported husband, and supposedly gave birth at ages between 55 and 70. Even if you shift the birth date by twenty years, having children at age 50 was pretty darn rare in the 1600s. Women who tried, mostly died. Also, the records indicate the man's wife was widowed while the children were somewhat young, but she was in no way feeble. I had to conclude that I do not know the name or dates of the woman. In another case, nearly every account cobbles together events from the lives of a father and his son to produce one generation where it seems certain there were two.

This kind of work is interesting and gratifying. The day went by like nothing.

Panning the arch

kw: travel notes, landmarks, photographs, genealogy

Late yesterday we returned from a five-day road trip. I was on a genealogical expedition and my wife accompanied me. We followed I-70 across five states into Missouri, where we stayed at Marshall, the county seat of Saline County, and paid a few visits to Malta Bend, where my father was born, and a goodly number of his ancestors. Drive time each way was a day and a half. We started out last Tuesday early, stayed the night in western Indiana, and arrived in Marshall about lunchtime Wednesday. The Marshall Public Library has a wonderful (though small) Genealogy Room with very friendly people to help.

A couple of hours there made it clear we had plenty of family graves to locate, in three cemeteries. One family was split between two cemeteries because of the fears of one couple that a property was not being well maintained. Fortunately, when we visited, we found it is being well cared for. So here is the rundown.

We first visited Ridge Park Cemetery in Marshall, where the caretaker showed us how to find the graves of the stray couple, the parents of my father's cousin. Then we had dinner and checked in to our hotel. The following day we went early to the Malta Bend cemetery. There we found ten of my father's ancestors' graves, and those of eighteen other relatives, including, sadly, five children and infants.

Some of the gravestone inscriptions faced west, and some faced east; a few faced north or south. There was no geographic pattern, such as facing walkways. It seemed instead that some people would face a grave to the east in anticipation of resurrection, while others would face it to the west as a symbol of the sunset of life. So while I photographed everything, I decided to return in the afternoon.

We went into Malta Bend to look for landmarks my father had marked on a map and an aerial photo. Only three buildings remained. The town had about 420 people in the 1920s, and there are about 250 now. It is a dying town. There are no stores, only two churches still operating, and people do all their business at Marshall or, if they want to drive 80 miles, in Kansas City. Before getting lunch we went to Little Grove Cemetery, south of Malta Bend. We found nine graves of interest there. It is about half the size of MB Cemetery, and both are smaller than one of the 26 sections of Ridge Park Cemetery. In the afternoon, back at MB Cemetery I was able to get much better pictures of almost half the gravestones. In total I got pictures of 39 headstones and several plotstones that announce a family group. Before returning to Marshall, we drove west to Grand Pass, population 52, where one of my great-grandfathers grew up. We saw no buildings of any great age there. For a dying town, it has had a complete turnover of construction in the past century.

I also obtained copies of many documents at the library, mostly lists of cemetery "residents", but also the record of an ancestor who was in the Civil War, and the surprise information that one couple I'd thought had died in Ohio, instead had died in Malta Bend and were buried there. That solves one family conundrum.

We turned in early, and awoke quite early Friday to watch the wedding of William and Katherine. Then we had breakfast and took off, arriving at our hotel in Springfield, Ohio in time for a rather late dinner. We slept well and drove home Saturday. On Friday, however, we took an extra hour to go into St. Louis to see the Gateway Arch.

Though we have passed by St. Louis a few times, the fastest route uses Hwy 270 north of the city, and we had never seen Gateway Arch. Fortunately, parking was not too costly, and there is no admission at the Arch unless you want to go up inside to the top. We are both fearful of heights (though we did visit the Empire State Building last month), and did not want to take the time either.

Getting to the parking garages proved a bit of a challenge. The usual approach, which the car's GPS unit took us down, happens to be partway under water because of the flooding on the Missouri River. We took some side streets, which are all cobblestone in that area; very difficult to drive on! However, we soon stumbled on a garage that advertised "Arch Parking" at a reasonable rate and parked there. It was right on the edge of the Gateway property, but the walk was still about a quarter mile.

The Arch gave me the chance to try some rather challenging panoramic photography. The grounds are simply not large enough to photograph the Arch with ordinary lenses. This is my best attempt. It is composed of three horizontal pictures, taken from an angle that I could get both "feet" in one frame. The panorama stitcher in Windows Live Photo Gallery did a fine job with them.

Then I followed the Arch's shadow to a spot where I could take the next panorama. It is composed of eight images, and it is evident that the stitcher has centered the fisheye simulation at the center of the final image. I had been expecting the ground to come out flat. Silly me! There are also a couple of fitting glitches. I tried using the Canon Stitcher, but it would not properly put the images together at all.


From the opposite side, on the stairway down to the river, I tried again. This time I was far away enough that I could use four images. Again, Stitcher failed completely, but the Windows Live software did a pretty good job with no glitches. The flat ground sure seems to swoop, though.


Both panoramas make it clear that I need to include lots more surrounding material for such projects, so I have something to crop out for a final image. I could probably use a circular mask on the backlit image. These two pictures are fun, but that is about it.

The trip was enjoyable though tiring. We have concluded that we'll fly in the future. A 2,200 mile trip is too much driving for a two-day visit. I have plenty to keep me busy with the family tree, for the next few months.

Weaving with straw

kw: family history, genealogy, writing

If locating a new ancestor is like finding a needle in a haystack, genealogy as practiced by my mother and two other women to whom I am related is like weaving the haystack into a tapestry, and using it to display one's needle collection. First and foremost, I am thinking of a book I received very recently, Buckland Filleigh: A Continuous Thread by Madeline Jane Taylor.

There are thousands of books that recount the family history of one specific family, but a much smaller number that weave together the history of a region or place out of all the family stories to be found in it. When a place is small enough, it is possible in one volume to encompass all the family histories, and that appears to be what Mrs. Taylor has done for Buckland Filleigh, a parish in Devon, England that is one of twenty-six in the Shebbear Hundred.

A Hundred is an administrative unit, as set up by the Saxons, consisting of one hundred "hides", a hide being a land area that can support one family. It is not hard to determine that Buckland Filleigh, then, contains but a handful of hides. But in modern times, by which I mean since the Industrial Revolution of the early 1800s, only a few families might live by farming, while the rest have "day jobs", so the chronicle of even this small place is rich with stories and is quite a challenge to compile.

I cannot yet review the book, as I am still reading it, and that right slowly. For the moment, it is quite amazing the amount of raw information from parish records, land office records, tax records and other sources that the author has compiled to produce the book. Was it Rumpelstiltskin who wove straw into gold? The nugget for which I obtained the book is the last appendix, an 8-generation descendancy chart for Stephen Vanstone, an ancestor of Mrs. Taylor's, and also one of mine. From noting where the line to her and the line to me branch, I reckon that we are eighth cousins.

Genealogy of the Lindsey Family, compiled by Emily Lindsey, is an unpublished manuscript that jump-started me and my mother in the genealogy obsession. We received in 1962 a typescript produced by my mother's cousin from the manuscript. This cousin had typed up the 1901 manuscript and added a few pages to bring it up to date to 1962. The total volume is but 30 pages of double-spaced typescript, containing the vital data for about 100 people, beginning with Thomas Macy, one of the original purchasers of Nantucket Island, Massachusetts. Miss Lindsey, my great-grandfather's sister, must have been about my age when she compiled the material, starting with the Lindsey family Bible.

The descendancy record from Thomas Macy to her generation occupies just five pages. The following twenty-one pages record other descendant families, Freelands, Pecks, Turners and others. My mother's cousin added Lusters, Wilcoxes, Vanstones and more, and one or two more recent generations of the other families, for a record of about 100 cousins through the fourth degree, most of whom I've never known.

Then there is my mother. She, my brothers and I figured out Miss Lindsey's system (by no means clear at first), and drew charts of the ten generations of our own family tree. Within a few years, my parents' nest emptied and my mother joined a genealogy club, among other pursuits. Then I found in a library The history of Nantucket: county, island, and town, including genealogies of first settlers by Alexander Starbuck. Mom told me, "At the genealogy club, we all have cake when someone finds one new ancestor. This book has about thirty, so we had quite a party!" That was in 1970, now forty years ago.

Just a few years ago, my brother sent all her genealogical records to me; she'd sent them to him when she could no longer continue to research and compile. He did quite a bit of research himself, in the years just before we all got computers. The core is a large, half-folio-size binder of pedigree pages, more than 100 of them. A box of photocopies from books, newspapers, and other sources rounds out the material. My brother did not add to the pedigree pages, but had gathered census records in both the US and England. Again, this was before computers: he photocopied microfilm records.

I think if she'd had time and energy, my mother would have written a book from all this. She is gone now six years. Since my brother sent me all the stuff, I've put it into Ancestry.com and the number of ancestors in the tree has grown to just over one thousand. The descendancy information on cousins I've chosen to track adds another hundred or so. That is quite a needle collection!

Graves matter

kw: genealogy, good finds, tools

I stumbled upon a very useful web site for certain genealogical information, Find a Grave. While it is often used to find graves of famous people, such as Paul Revere, it is most useful as a first place to look for information about the burial of a relative.

This shows the search I used to locate someone six generations back in my family, tree, Phebe Lamb (née Macy). This search returned four records, one of which was in the Lamb Cemetery, with the right date of death; see below:

This is a good example of a grave record for which a useful amount of information has been entered. The Lamb family was prominent, and has many descendants, so someone has not only taken a picture of the graveyard entrance, but also of the gravestone, a double stone for both Phebe and her husband John Lamb.

While a headstone date is not always accurate, it usually has the most accurate record of the date of death. It is at least a great starting point for pinning down the dates and locations of a person's life. I am very thankful to the people such as those of "Vermilion County Saving Graves" who make these records for all of us.

Impossible ancestors

kw: genealogy, software

As one might guess from several recent posts, I've been spending a lot of time on my family tree at ancestry.com recently. I finally purchased the companion software, Family Tree Maker, the 2011 version. It has a few specialized tools I've been wanting. One is the Errors Report, which audits a list of conditions, particularly date anomalies.

When I first began loading the family data, the web site had an option to take "hints" that included copying up to five generations from another public tree or from the One World Tree, which is a semi-curated meta-tree. Once I had entered the people and relationships I knew already, I happily took hints pretty freely. I got a lot of junk in the process. I am glad that the download options are much more restricted now, a generation at a time, with the chance to check each person before clicking OK.

Anyway, the Errors Report produced a five-page list of people, mostly those who are recorded as having married or had children prior to their 13th birthday, after their death, or past childbearing age. I'll go through the targeted sections of the tree and remove those that are most suspect, unless there is new information with better dates. While I like to collect ancestors, I don't want to collect imaginary ones!

Is moving genetic?

kw: genealogy, family history

In answer to a friend's question, I said something like "all my ancestors come from different places." Then I looked into it and found it is true on two levels. Firstly, from four to fourteen generations back, I have lots of immigrants to and emigrants within the continental United States and Canada. Secondly, just picking the fourth generation, my eight great-grandparents each have a different birthplace from all the others.

Running down the Ahnentafel (ancestor table) from father's father's father to mother's mother's mother, the places of birth are England, Canada, Missouri, Ohio, Arkansas, Alabama, Illinois, and Indiana. The next generation prior, of sixteen people, twelve states or countries of birth are represented. None of the above was born in California, but I was, so every generation moved somewhere.

No wonder I have been a wanderer. I come from a long line (a dozen long lines) of people who moved multiple times in their lives. I find it astonishing that I've lived in the same place for fifteen years now. It is more than twice as long as I lived anywhere else. So, OK, I am slowing down. Not at a full stop, though, not yet!

One third Irish?

kw: genealogy, family history

A guy announces that he's one-third Irish, and a friend challenges him, "That's impossible? How can you figure you are one-third anything?" He answers, "It isn't hard at all. My Mom isn't Irish at all, and my Dad is two-thirds Irish!"

I happen to be blessed with many ancestors who were good record-keepers, so I know a lot about my family heritage. I recently began gathering together all the information I have about the ancestors who were immigrants to America. I know that, except for a line of Cherokees, all of my ancestry goes through immigrants, but I don't know who the actual immigrants were in all cases. I can determine about 2/3 of my heritage at the moment, and I think I'll be able to increase that with a little more study.

If I add up the influence of each immigrant I know about (there are 152), it totals about 62% of the total. It works this way. A great-grandparent (three generations ago) has a factor of 1/8, or 12.5%, while a great-great-great-grandparent (five generations back) has a factor of 1/32, or 3.125%. Some of those 152 are 12 generations back, a factor of 1/4096 or 0.0244%. It takes a bunch of them to equal a great-great-grandparent.

So here is the approximate breakdown. Of the 62% I know, 22% (just over one third of the 62%), is English, and 21% is Irish. Less than half the rest is Welsh, a bit less is Scottish, and I have one known Cherokee line and one known German line, far enough back to be about 2% each. If those proportions fairly represent my entire heritage, then I am about 1/3 English and 1/3 Irish (But only "about", not exactly 1/3!). And that surprises me. I'd gotten the impression from the prominence of one Scottish line that I was mostly Scottish, but it is closer to 8%. The largest contingent, by a small margin, is English.

Another census mystery

kw: discoveries, genealogy, census records

In this post from about three years ago, I reported on an ancestor of mine who appears twice in the in the 1840 census. This composite image shows portions of two pages from the 1920 census in which my grandmother's brother and his wife were recorded twice.

In the upper section, William F. Nye and his wife were with the wife's mother Mary A. Levy in Carrollton City, MO on 13 Jan 1920 when the census taker visited. In the lower section the same couple (the wife's name is Katherine) were with William's parents, John and Cynthia Nye in Malta Bend, MO, just a week earlier. The two towns are about sixteen miles apart.

I am not sure if they lived at either address, though I think it most likely that they lived with Mrs. Levy, a widow. It may be that there is still a record somewhere of their being visited by a census taker in their own home!

Calculating with Ahnentafels

kw: family history, genealogy

A few days ago I wrote about Ahnentafel numbers, or "ancestry table" numbers. See the explanation there.

When I am confronted with an Ahnentafel number (AN) larger than about 32, I have to do some work to figure out where in the family tree this person fits. Converting the number base makes it simpler. I have a scientific calculator that can convert from base 10 to bases 2, 8 and 16. I use base 2 for smaller numbers, and an intermediate of base 8 for larger ones, for which I can pretty easily convert to base 2 (binary) for whatever next step I have in mind.

If you don't have a calculator that will do it for you, you can convert from base 10 to base 8 with pencil and paper, using successive division and keeping remainders. I'll do an example with the AN 10569:

10569/8 = 1321 with a remainder of 1; that is what the first two lines show. You keep dividing until you get a number smaller than 8, and that is your last remainder. Based on the calculation shown, the base 8 (octal) representation of 10569 is 24511.

For many needs, it is most convenient to know the binary representation. For example, if you have an AN of 19 for an ancestor, in binary it is 1011. The first 1 is always you, and after that zeroes represent males, and ones represent females, so this is your father's mother's mother. Your father's father's father has a binary representation of 1000, which is 16. Memorize the table that follows if you don't already know these:

These make it simple to turn 24511 (8) into binary: 010 100 101 001 001 or 10100101001001, discarding any leading zeroes. Now, you can read this off as "my father's mother's, etc." but it has a more practical use. I have for years kept family records according to which great-grandparent's line they were in (Great grandparents have AN's of 8-15, or in binary, 1000-1111). The first four binary digits in 10569 are 1010, which equals 10 in decimal. This works out to the line of my father's mother's father.

Also, the charts you can print from Ancestry.com have five generations. The root sheet thus has people with AN's from 1 (you) to 31. If, as I do, you print successive sheets starting with the people in the rightmost column (fifth generation, including you), you can figure out where 10569 is, such as which sheet she is on (odd AN's are for females). Take the number five bits at a time, but overlapping by one bit, and converting a leading zero to a one: 10100, (1)1010, (1)0100, (1)1. These four binary numbers represent 20, 26, 20, and 3.

I number sheets in the corner according to the AN of the root person for that sheet. The figuration here is a bit tricky:

• The root sheet is sheet 1.
• The second sheet with the line to 10569 is sheet 20.
• The third sheet is 20x16+10 = 330 (26 is 16+10).
  
• The fourth sheet is 330x16+4 = 5284.
• Person 10569 is in position 3 (mother of root person 5284).

I find these numerical tools for converting to octal and binary very useful. I have seen articles advocating the use of wholly octal AN's, and there are some benefits to doing so. With a bit of practice, you can just about read off the person's affiliation by scanning the AN. However, putting the AN's on the sheets, if you don't have software that does it for you, would be tricky: in octal, 200x2 = 400, but 217x2 = 436. It takes a lot of practice to do this comfortably.

Ahnentafel numbers

kw: family history, genealogy

Some years ago, I came up with a scheme to number ancestors, and thought it was quite original. It didn't take me long to find out it is very old, dating back to 1590, when the first Ahnentafel, or Ancestor Table, was published by Michaël Eytzinger with this numbering system, which is also known as the Eytzinger Method.

The concept of Ahnentafel Numbers is simple, and is based on the fact that each generation you go back, you have twice as many ancestors as in the prior one: two parents, four grandparents, eight great grandparents, and so forth. If you make a pedigree chart in the ordinary way, with the father shown on the line above the mother in each couple, then you number this way:

• Your number, as the root of the table, is 1.
• Your father's number is 2 and your mother's is 3.
• Your father's parents are numbered 4 and 5, while your mother's parents are numbered 6 and 7.
• The next generation gets numbered from 8 to 15; and so it goes.

The number goes with the position in the chart, whether or not you know who the person is. Thus your father's father's father's father's father's father (six generations back in male succession) is numbered 64. The male succession anchors the entire sequence, always having numbers that are powers of two: 2⁶=64.

Before reading further, click on the chart below (clipped from Ancestry.com) to see the full-size image, so you can more easily read the green numbers next to the names.


This is a small Ahnentafel for John D. McCown, an ancestor of mine. Note that two ancestors are not known. The numbers 12 and 13 belong to those two slots, so if some day I find out who they were, they get those numbers, which are reserved for them.

In my own Ahnentafel charts, John D. McKown is numbered 42, so the male succession of this chart continues 84 for James B., 168 for James, and 336 for Gilbert McKown. Priscilla Turner at the bottom right is then numbered 343. (She and her husband are descended from Mayflower families, so information about them has been easy to find.)

If you have a calculator that can convert decimal numbers to binary, you can determine the father-mother sequence that leads to an ancestor when you know the person's Ahnentafel Number. For John D. McKown, 42 is 32+8+2, or 101010. I am the first 1, my father is the second digit, a 0 (because it is even), his mother is next, then her father, then his mother, then the last father, John D. Or, to be short, John D. McKown is my father's mother's father's mother's father.

I have very few quibbles with Ancestry.com, but one of them is that I wish I could print a pedigree that included the Ahnentafel numbers. I've been adding them by hand to the pedigree sheets I print. Since I know one line of ancestors going back 24 generations, some of those numbers have eight digits! Though numbers that big are unwieldy, most of my pedigree has numbers of four digits and fewer. They are a great help for bookkeeping. See this Wikipedia article for a detailed explanation of Ahnentafel Numbers.

There is a king back there

kw: musings, genealogy

I just spent a long evening tuning up some of the Hints in my family tree at Ancestry.com. I also numbered all the people in the primary reference I used to begin the online tree, titled "Genealogy of the Lindsey Family", compiled in 1901 by my great-grandfather's sister, and updated by an aunt in 1962. It really gave us a leg up on the family tree my mother and I worked on through the 1960s and 1970s, and which she continued to compile through the 1990s.

One thing about genealogy as a hobby: it is a huge consumer of time. The online experience just makes it more intense. I "discovered" several new ancestors tonight, back in the mid 1600s. At the genealogy club my mother belonged to, they would hold a party every time someone found a new ancestor. When we found in the library a book with a complete family history of the Nantucketers from the founding in 1659 to about 1950, we "discovered" forty or more ancestors of one Joseph Macy, the one who first moved from Nantucket to the Carolinas. He is six generations back in my tree, while the founders are nine generations back, and many of them have three or four more generations that are known.

Then a few years later, someone who gave a talk at the club asked my mother, "Nantucketers? Are you descended from Dorcas Gayer? Then you're descended from Charlemagne!" There is still debate whether one of the links in the Gayer family tree is genuine, but if so, then Charlemagne is back there, 39 generations. I have my tree traced back to Edward I Plantagenet, who is 23 generations back, and I figure that is about far enough. The connection is almost meaningless.

Almost anyone of European ancestry is descended from the kings somewhere (though tracing it is another matter). Considering that the early "royalty" were just the biggest bullies around, it is a dubious distinction. Anyway, there is a numerical point that interests me here.

The human genome contains about 25,000 genes. If you divide 25,000 by two fifteen times, you get 0.76, which means you have a 76% chance that a single gene that was present in a particular ancestor fifteen generations ago is present in you. Of course, in that generation, you have about 32,000 ancestors, so there are plenty of people for every single gene to come from. But what about 23 generations? 2²³ is 8,388,608. Divide that by 25,000 and you get 336. There is one chance in 336 that any single gene from Edward I would be found in my genome.

Of course, as kings do, he had lots of children, most of them illegitimate, and in 23 generations, it is likely that some distant and not-so-distant cousins married one another, so there are more chances than exactly 1/336. But it is still not too likely.

I find the stories closer to this time of more interest. I am lucky to know who all of my great-great grandparents are, and well over half of the generation before that. Several of these were immigrants to America, and one was a Cherokee, so the immigrant there is about 500 generations back. The line I was researching today all lived and died in Salem, New Jersey. Any living descendants are about eighth cousins.

By the way, here is how I figure "Nth Cousin" and how many times removed. It is the rule of G's. First cousins share a grandparent. That is the first "G". Count the G's in the shortest line. For example, if two people share a great-great grandparent, that is three G's so they are third cousins. But if they are of different generations, the extra G's in the longer line are the "times removed". So, my third cousin and I are descended from a particular great-great grandmother. We are of the same generation. But his daughter is once removed, and her daughter is twice removed, from me. I have a son, and the daughter is his fourth cousin, while the daughter's daughter is his fourth cousin once removed.

For those of us who know lots of our ancestors, and perhaps lots of cousins, at various removes, we know that, when people say, "Family matters", it means, "Close family matters." An eighth cousin relationship is possibly interesting, but hardly significant.

A cousin and a half

kw: genealogy, puzzles

This interesting linkage showed up as I deciphered the relationship between my grandmother Liz and her favorite cousin "Billie". I have letters between them, and Will-Ella usually signed herself "Bill", sometimes "Billie", and only once by her given name, in a formal condolence letter when Liz'z father died.

With the help of a relative who has better records than I for this branch of the family, I found that these two cousins are doubly related. It hinges on the relationship between JGK's two wives. Mary was Jane's aunt, through her sister Marg.

That means that, while Ella and Kate were half-sisters, they were a little closer than that, but I haven't figured out how; perhaps they are also half-cousins.

But for sure, Liz and Billie are half cousins via their grandfather, but half cousins once removed via their grandmothers. I don't know if they ever thought about it. They didn't write about it. They were best of friends and frequent correspondents. That's what mattered to them.

Family history census mystery

kw: discoveries, genealogy, census records

The name "McKown" is one of the most frequently misspelled names in US Census history. Here we have two brothers, recorded in the 1860 census, whose surname is given as "McKowan". Not too bad, compared to McGowan, McCoun, McKeon and McCowen (see below).

The elder brother, John D McKown, is my great-great grandfather. He it is who received the old family fiddle sometime after 1840. [11/9/08: generational note, found to be inaccurate, removed]

Here we see John, aged 41, and his 27-year-old brother, living next door to one another in Marshall, MO, working as Plasterers. But my focus here is on the whereabouts of John D McKown ten years earlier. He was rather hard to find in the 1850 census. I dug, and dug, and finally found him...twice!

Here is John's family in 1850. His name is recorded as "McCowen" and no middle initial is given. His age looks like 37, but he was 31 at the time. The census taker seems to have dragged into his "1" making it look more like his usual "7". His occupation is states as Bellowsmaker. I guess that was a skill of sufficient demand to be one's main occupation. It is also a clue to the veracity of a second record.

This record is from Ward 4, St. Louis, MO, where the family lived before moving to Marshall. While the violin was obtained in St. Louis, in Marshall the daughter Margaret (spelled "Margarette" here) met J.G. Nye, my great-grandfather.

I found this record after a bit of a search. It took a lot more digging than the 1860 one, but the fact that McKown was misspelled in the 1860 record kept me looking at all the variations. A "soundex" search of an Internet index helped a lot.

A few days ago I took another look at the record I'd found for John's parents, James B and Bethia (or Bertha in some records). Here the surname is spelled McKeon. There John D was, aged 31, with his 17-year-old brother James and three other siblings. Both he and his father are listed as Bellowsmakers (that squiggle is an 1850 "ditto" mark: "Do"). This record is from Ward 3 of St. Louis.

I don't yet know the exact addresses, but I suspect the wards were not very large, and John and his father may have been in business together and lived quite nearby. The census taker happened to come by when father and son were at the father's home, so he got recorded as part of that household on Sept. 16, 1850. The record of John in his own home was made on Sept. 20.

I wonder how many people got recorded in the census? This is the only case I've heard of.