If we work long enough and get enough info., would the family tree end to the point that we all come from two people?

Question

This would be a question for the professional wikitreers. I don't have the sources, time or money to find some things out but I have wondered how far and what would be the result of an endless family tree?

Comments

Current research does not support such a theory. If you do a Google search for genetic origins on man, or a similar topic, you get quite a number of hits. Just one, for example, is https://www.nhm.ac.uk/discover/news/2021/february/modern-human-origins-cannot-be-traced-back-to-a-single-point.html

Answer 1

No, because WikiTree doesn't allow for Before Christ dates (profiles).

Answer 2

Yes It will. Although the Most Recent Common Ancestor (MRCA) is before widely available records.

However if WikiTree or a successor continues for centuries to come, the MRCA will move forward in time and eventually be on WikiTree for profiles on there.

Exactly how long this would take, I'm not sure. People are more mobile than they used to be which speeds up uniting branches of the tree. Also very enthusiastic WikiTree members might consider marrying someone just to join two branches together. Or a religious group may have that aim.

I suppose a database query could be custom written to find the ancestors with most descendents on WikiTree.

Edit: In theory most people of Western European ancestry are descended from [https://www.wikitree.com/wiki/Carolingian-77] though the people who have been able to show that and have put a category on their profile are much more limited [https://www.wikitree.com/wiki/Category:Descendants_of_Charlemagne].

     Tim

Answer 3

No, origin of a species is not that cut and dried. There's a long period of change where members of one population can interbreed with another. There might be a specific mutation from one ancestor (male or female) that we all inherit, but it wouldn't be a particular couple that had children together that were the new species.

Even after homo sapiens was distinct, when we first got into Europe we interbred with the Neanderthals, and Europeans carry some of their DNA around today. In Asia, many people carry DNA from the Denisovan branch of hominids. (The Denisovans are thought to give the Tibetans their ability to thrive at high altitudes).

Even dog breeds, which intentionally have highly manipulated genetics, don't come from one pair of male and female dogs that had puppies and only those puppies were ever bred together. It developed over time from a larger population.

Answer 4

Nope. What it would show is that everyone alive now descends from everyone alive beyond a certain point in the past who left descendants to the present: https://en.wikipedia.org/wiki/Identical_ancestors_point

This is probably relatively recent (within the last few thousand years). If you look at estimates of historical population, the current population of the USA (c. 330 million) is nearly equivalent to the estimated population of the entire planet 800 years ago (c. 350 million): https://en.wikipedia.org/wiki/Estimates_of_historical_world_population

Not only that, the number of possible (although not actual!) ancestors one has doubles with every generation; 29 generations back, one has over 536 million possible ancestors, which is around twice the human population of Earth at the time. So one must necessarily be descended from everyone in a given population who left descendants to the present, many times over. If your ancestry is mostly English, you'll find that most of your lines go back to England...but a few will go to France, and Italy, and Hungary, and Constantinople, and Kievan Rus, and maybe one or two or a few dozen out of all those possible billions of ancestral lines, eventually, will go back to China, or Japan, or Mongolia, or Ethiopia, etc.

Answer 5

No. For those with European ancestry, it is virtually certain that most of your tree 20+ generations back would consist of European peasant ancestors. And there are simply no records of any European peasant ancestors from that period (or before). So even if WikiTree got to the point where every extant available record was on here and connected to the right person/people, we Europeans would still have hundreds of thousands of brick walls. I suspect the answer is pretty much the same for other ancestral groups.

Answer 6

There is a religious group that tries to prove this, and comes up with this argument once in a while. But most people, at least me, will say: no. Homo sapiens is much older than one can ever trace with sources. Also, species do not evolve from two single individual specimens.

Answer 7

The result of an endless family tree would be a single-celled organism 4 billion years ago.

Many humans came from many apes, so there wasn't a "first human" so to speak that we all came from.

However, every human on Earth today is descended from the same people, not because they were first, but because their DNA spread enough that it mixed in all of us eventually.

Comments

The first molecules which made copies of themselves can't have existed inside a "cell" as we know it today. There's a long chain of tiny incremental steps over eons of time from lifeless matter, through amino-acids, to the first single-cell organism that we may be able to define as "life". The beginning, as I see it, was self-replicating molecules.

Answer 8

What an interesting question! There are lots of ways to think about it. Here's mine.

We all come from the same two ancestors, Adam and Eve. According to the Jewish calendar, they were created 5782 years ago (3761 B.C.)

Looking at your own family tree, what is the earliest ancestor you've found? (Mine, for example, goes back about 1100 years). How long did it take you to get back that far? (Mine, for example, has taken me about 40 years.) If you work at that same rate, how much longer would it take get back to Adam and Eve?

Comments

Moving past the issue of a strictly literal interpretation of the Bible, you have a major problem in that paper records largely disappear by about 500 or 600 years ago for everybody but some royalty. Even their names aren't recorded. So there's no way to "work at the same rate" to go farther back in time.

DNA might help to some degree, but it would never be exact that far back. Each person gets 50% of their DNA from their mother and 50% from their father, but there's no indication which part is which. And it's entirely possible that by the time you get to a great-great-great grandparent, you might not have any of their DNA at all, even though they are a blood ancestor.

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Thanks for the comment, Rob. I didn't intend this as a definitive answer, just as another way to think about the question. (I also thought about it in same way as in other answers, and I spend some time calculating powers of 2).

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I can accept that. It's good to have multiple views available.

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Apparently no one liked thinking about Adam and Eve, so I've just added another answer with some other possibilities.

Answer 9

This an interesting question. There are many ways to think about it.

1. How far back would we need to go? According to my own DNA analysis, my maternal line (my mother's . . . mother's. . .mother's . . .)  goes back 150,000 years. My son's paternal line (his father's .. . father's. . . father's . . .) goes back 275,000 years. DNA analysis also tells me that at least one of my ancestors was a Neanderthal.

2. How far back can anyone trace their ancestors? The most famous family tree is that of Confucius (551-479 BC) who is descended from King Tang (1675-1646 BC). For this and other extensive trees, see this article.

3. To show that everyone is descended from the same two people, you would need to determine the ancestry of everybody. How many people is that? (Question for the mathematicians among us.)

4. Genealogists might tell you that there will always be "brick walls". If you had a time machine, could you travel back in time to discover the missing information?