7 ms·

If the average age of giving birth is 25, Mark Antony would be about 80 generations ago. With each generation back doubling the number of ancestors (2 parents,

by jl6 4y ago

If the average age of giving birth is 25, Mark Antony would be about 80 generations ago. With each generation back doubling the number of ancestors (2 parents, 4 grandparents, …), this person has a theoretical 2^80 ancestors - somewhat more than the number of people that have ever lived. So clearly that logic is flawed, and the family tree must in fact be a family web - but potentially a very, very wide one. I wouldn’t be surprised if a large portion of the population of Italy were also descendants of Mark Antony, albeit without the famous lineage to prove it.

LarsDu88 4y ago
This is the correct answer. The entire population of Europe is about as descended from Mark Antony as that Georgian noble house. Only the Y-chromosome is lineally passed across such long time spans
- rongopo 4y ago
  Does it follow that same would apply for all humans of Mark Antony's time?
  - NeoTar 4y ago
    Kinda! This is covered in Randall Munroe's (of XKCD fame) latest book - What If 2; chapter 33 "Ancestor Fraction" Obviously a human who did not have any children cannot be the ancestor of anyone - this includes the circa 50% of humans who died during infancy, and the 25% of adult humans who did not have children. Also, for some people who had children the line will die-out; if you have four children all of whom die in infancy, your line dies out. If none of your grand-children have children, your line dies out. Randall quotes a study which estimated that this applies to 40% of all people who ever had children. So, taken together roughly 25% of all humans who were ever born went on to have children and form a part of the modern human 'ancestor web'. In Summary: If you picked a random human of any age from the time of Mark Antony there is a roughly 25% they are an ancestor to all humans. If they are an adult that rises to 50%, and if they already have kids it rises to about 62.5%.
    - mannykannot 4y ago
      Does this take into account geographical limitations? I don't know about today, but if you applied the same analysis to the global population of 1600, it seems impossible on geographical grounds for either Mark Anthony or one of his contemporaries in South America to be an ancestor of everyone alive in 1600.
    - tomp 4y ago
      You’re assuming much more “cross-polination” than actually happened. Humans didn’t use to mix geographically (hence different races). And there’s isolated subgroups that didn’t mix or mixed much less (e.g. Jews in Europe)
    - saalweachter 4y ago
      Is that "are" or "will be" an ancestor to all humans?
  - User23 4y ago
    No. I don’t know the names of any great first century subsaharan African or Native American leaders, but even 80 generations back there are almost certainly none in my family tree. On the other hand I wouldn’t rule out some Asian steppe leader being in there somewhere.
- ginko 4y ago
  >Only the Y-chromosome is lineally passed across such long time spans There's also the mitochondrial DNA passed along female descandants.
  - gweinberg 4y ago
    Good luck inheriting Mark Anthony's mitochondrial DNA.
    - deleted 4y ago
      [deleted]
- TylerE 4y ago
  The real give away is in the bio: Prince Theodore D. Kopaliani is a member of the Bagrationi Royal House.
simonh 4y ago
Furthermore for an ancestor that far back, many of their descendants may not even have inherited any of their actual genes.
- User23 4y ago
  Given that we share somewhere well north of 99% of our genes with every other human being that sounds unlikely.
  - simonh 4y ago
    Oh sure, we'll have many of the same genes, but got them from other ancestors.
User23 4y ago
This is called pedigree collapse.
photochemsyn 4y ago
There also wasn't much mixing of isolated populations of humans, leading to a relatively large amount of inbreeding. Sort of like a graph with clusters of heavily linked nodes and only a few links between the clusters. https://www.newscientist.com/article/mg22029453-500-inbreeding-shaped-the-course-of-human-evolution/ https://www.newscientist.com/article/mg22029453-500-inbreedi... > "“In the distant past, human populations were probably only in the thousands or at best tens of thousands, and lived locally, exchanging mates only with their nearest neighbours.”" International shipping, and now, air travel, has changed this - the 20th century and the population boom have led to more genetic mixing than at any point in human history.
- ch4s3 4y ago
  We have pretty good evidence since 2013 of bands of neolithic humans moving over really tremendous distances. There's good evidence in the Americas of people moving from the Great Lakes down to the Gulf and beyond. Once horses were domesticated in Eurasia, all bets are off and we see mass migration from the steppe through to all of Europe, India, Iran, the Horn of Africa, and other places. This didn't happen in a single life time, but people on horseback with carts really got around.
  - samatman 4y ago
    All of which is true, but Mark Anthony gets us well into the historical period. We have a pretty good sense from that of who did and who didn't get around. It's surely the case that the vast majority of Japanese on Hokkaido are not descendants of Mark Anthony. On Kyshu, maybe, the Portuguese contributed some genes there. We can really only be detailed about this with a Y chromosome for a man, or mitochondrial lineage for a woman, and that only covers the case of lineal descent. Not only can we not determine with confidence who is or isn't a descendent, even given a complete DNA sequence we don't have: most of those descendents won't have any Mark Anthony DNA at all! Chromosomes are more chopped than sifted, if that makes sense, I'm going on memory here, but somewhere around the 12th generation, we start having phantom ancestors: they existed, but left no record in our genes.
Bjorkbat 4y ago
I wouldn't be surprised if every person in Europe and every person in the Americas with European ancestry was descended from Mark Antony. https://www.theguardian.com/science/commentisfree/2015/may/24/business-genetic-ancestry-charlemagne-adam-rutherford https://www.theguardian.com/science/commentisfree/2015/may/2...
PaulDavisThe1st 4y ago
Given that the lineage has not died out, the average number of ancestors per generation is not zero. If you assume it is 1.2, that would mean about 2M descendants, which seems much more reasonable.
pjlegato 4y ago
All real family trees are not tree-shaped but diamond-shaped due to inbreeding (often very distant), a phenomenon geneaologists call "pedigree collapse": https://en.wikipedia.org/wiki/Pedigree_collapse https://en.wikipedia.org/wiki/Pedigree_collapse
- P5fRxh5kUvp2th 4y ago
  If it's "very distant" is it really inbreeding?
  - lofatdairy 4y ago
    It's inbreeding by the technical definition/understanding but obviously it's not inbreeding from a practical/biologically concerning standpoint.
    - P5fRxh5kUvp2th 4y ago
      In that case we're all inbred, so what does the word mean?
      - JumpCrisscross 4y ago
        > we're all inbred, so what does the word mean Genealogically, it means a family tree which is not a binary tree [1]. The measure is meaningful over a certain number of generations. Everyone is inbred over infinite generations, assuming a universal common ancestor. That doesn't sap the term of meaning. Medically, we look at the coefficient of coancestry [2]. Practically, I think we trace back 3 to 4 generations, my source being grandparents (2) is a common word, great grandparents (3) less so but widely understood, and great great grandparents (4) being something few people keep track of. [1] https://en.wikipedia.org/wiki/Binary_tree https://en.wikipedia.org/wiki/Binary_tree [2]https://link.springer.com/referenceworkentry/10.1007/978-1-4020-6754-9_3275 https://link.springer.com/referenceworkentry/10.1007/978-1-4...
      - cactacea 4y ago
        The same thing it always meant. Like many things, just because it's a continuum and not binary doesn't mean it's a useless concept.
krmboya 4y ago
Nice breakdown. Maybe it works the other way too.. that a large percentage of the population alive today can count rulership/prominence in their ancestry. I speculate that when times were hard for humans in the course of history, those who were better off were more likely to successfully raise kids to adulthood, who in turn had better chances of establishing their own families
- irrational 4y ago
  Yes, every single person alive that has any ancestry from Western Europe is a direct descendant of William the conqueror and Charlemagne and others. But they are also all direct descendants of the servant who cleaned out their potty every morning (presuming that servant had descendants). Claiming royal descent is not a big deal since we are all descended from everyone that lived back then and has descendants to this day. https://waitbutwhy.com/2014/01/your-family-past-present-and-future.html https://waitbutwhy.com/2014/01/your-family-past-present-and-... https://nautil.us/youre-descended-from-royalty-and-so-is-everybody-else-236939/ https://nautil.us/youre-descended-from-royalty-and-so-is-eve...
irrational 4y ago
You should read up on family trees. This is an extremely well known thing and you can find a lot of articles that answer this question.
- bin_bash 4y ago
  This comment is begging for a link—or at least a description of this "extremely well known thing"
  - irrational 4y ago
    https://waitbutwhy.com/2014/01/your-family-past-present-and-future.html https://waitbutwhy.com/2014/01/your-family-past-present-and-... https://nautil.us/youre-descended-from-royalty-and-so-is-everybody-else-236939/ https://nautil.us/youre-descended-from-royalty-and-so-is-eve... https://sci-hub.st/10.1038/nature02842 https://sci-hub.st/10.1038/nature02842

by jl6 4y ago

LarsDu88 4y ago

This is the correct answer. The entire population of Europe is about as descended from Mark Antony as that Georgian noble house. Only the Y-chromosome is lineally passed across such long time spans

rongopo 4y ago
Does it follow that same would apply for all humans of Mark Antony's time?
- NeoTar 4y ago
  Kinda! This is covered in Randall Munroe's (of XKCD fame) latest book - What If 2; chapter 33 "Ancestor Fraction" Obviously a human who did not have any children cannot be the ancestor of anyone - this includes the circa 50% of humans who died during infancy, and the 25% of adult humans who did not have children. Also, for some people who had children the line will die-out; if you have four children all of whom die in infancy, your line dies out. If none of your grand-children have children, your line dies out. Randall quotes a study which estimated that this applies to 40% of all people who ever had children. So, taken together roughly 25% of all humans who were ever born went on to have children and form a part of the modern human 'ancestor web'. In Summary: If you picked a random human of any age from the time of Mark Antony there is a roughly 25% they are an ancestor to all humans. If they are an adult that rises to 50%, and if they already have kids it rises to about 62.5%.
  - mannykannot 4y ago
    Does this take into account geographical limitations? I don't know about today, but if you applied the same analysis to the global population of 1600, it seems impossible on geographical grounds for either Mark Anthony or one of his contemporaries in South America to be an ancestor of everyone alive in 1600.
  - tomp 4y ago
    You’re assuming much more “cross-polination” than actually happened. Humans didn’t use to mix geographically (hence different races). And there’s isolated subgroups that didn’t mix or mixed much less (e.g. Jews in Europe)
  - saalweachter 4y ago
    Is that "are" or "will be" an ancestor to all humans?
- User23 4y ago
  No. I don’t know the names of any great first century subsaharan African or Native American leaders, but even 80 generations back there are almost certainly none in my family tree. On the other hand I wouldn’t rule out some Asian steppe leader being in there somewhere.
ginko 4y ago
>Only the Y-chromosome is lineally passed across such long time spans There's also the mitochondrial DNA passed along female descandants.
- gweinberg 4y ago
  Good luck inheriting Mark Anthony's mitochondrial DNA.
  - deleted 4y ago
    [deleted]
TylerE 4y ago
The real give away is in the bio: Prince Theodore D. Kopaliani is a member of the Bagrationi Royal House.

simonh 4y ago

Furthermore for an ancestor that far back, many of their descendants may not even have inherited any of their actual genes.

User23 4y ago
Given that we share somewhere well north of 99% of our genes with every other human being that sounds unlikely.
- simonh 4y ago
  Oh sure, we'll have many of the same genes, but got them from other ancestors.

User23 4y ago

This is called pedigree collapse.

photochemsyn 4y ago

There also wasn't much mixing of isolated populations of humans, leading to a relatively large amount of inbreeding. Sort of like a graph with clusters of heavily linked nodes and only a few links between the clusters. https://www.newscientist.com/article/mg22029453-500-inbreeding-shaped-the-course-of-human-evolution/ https://www.newscientist.com/article/mg22029453-500-inbreedi... > "“In the distant past, human populations were probably only in the thousands or at best tens of thousands, and lived locally, exchanging mates only with their nearest neighbours.”" International shipping, and now, air travel, has changed this - the 20th century and the population boom have led to more genetic mixing than at any point in human history.

ch4s3 4y ago
We have pretty good evidence since 2013 of bands of neolithic humans moving over really tremendous distances. There's good evidence in the Americas of people moving from the Great Lakes down to the Gulf and beyond. Once horses were domesticated in Eurasia, all bets are off and we see mass migration from the steppe through to all of Europe, India, Iran, the Horn of Africa, and other places. This didn't happen in a single life time, but people on horseback with carts really got around.
- samatman 4y ago
  All of which is true, but Mark Anthony gets us well into the historical period. We have a pretty good sense from that of who did and who didn't get around. It's surely the case that the vast majority of Japanese on Hokkaido are not descendants of Mark Anthony. On Kyshu, maybe, the Portuguese contributed some genes there. We can really only be detailed about this with a Y chromosome for a man, or mitochondrial lineage for a woman, and that only covers the case of lineal descent. Not only can we not determine with confidence who is or isn't a descendent, even given a complete DNA sequence we don't have: most of those descendents won't have any Mark Anthony DNA at all! Chromosomes are more chopped than sifted, if that makes sense, I'm going on memory here, but somewhere around the 12th generation, we start having phantom ancestors: they existed, but left no record in our genes.

Bjorkbat 4y ago

I wouldn't be surprised if every person in Europe and every person in the Americas with European ancestry was descended from Mark Antony. https://www.theguardian.com/science/commentisfree/2015/may/24/business-genetic-ancestry-charlemagne-adam-rutherford https://www.theguardian.com/science/commentisfree/2015/may/2...

PaulDavisThe1st 4y ago

Given that the lineage has not died out, the average number of ancestors per generation is not zero. If you assume it is 1.2, that would mean about 2M descendants, which seems much more reasonable.

pjlegato 4y ago

All real family trees are not tree-shaped but diamond-shaped due to inbreeding (often very distant), a phenomenon geneaologists call "pedigree collapse": https://en.wikipedia.org/wiki/Pedigree_collapse https://en.wikipedia.org/wiki/Pedigree_collapse

P5fRxh5kUvp2th 4y ago
If it's "very distant" is it really inbreeding?
- lofatdairy 4y ago
  It's inbreeding by the technical definition/understanding but obviously it's not inbreeding from a practical/biologically concerning standpoint.
  - P5fRxh5kUvp2th 4y ago
    In that case we're all inbred, so what does the word mean?
    - JumpCrisscross 4y ago
      > we're all inbred, so what does the word mean Genealogically, it means a family tree which is not a binary tree [1]. The measure is meaningful over a certain number of generations. Everyone is inbred over infinite generations, assuming a universal common ancestor. That doesn't sap the term of meaning. Medically, we look at the coefficient of coancestry [2]. Practically, I think we trace back 3 to 4 generations, my source being grandparents (2) is a common word, great grandparents (3) less so but widely understood, and great great grandparents (4) being something few people keep track of. [1] https://en.wikipedia.org/wiki/Binary_tree https://en.wikipedia.org/wiki/Binary_tree [2]https://link.springer.com/referenceworkentry/10.1007/978-1-4020-6754-9_3275 https://link.springer.com/referenceworkentry/10.1007/978-1-4...
    - cactacea 4y ago
      The same thing it always meant. Like many things, just because it's a continuum and not binary doesn't mean it's a useless concept.

krmboya 4y ago

Nice breakdown. Maybe it works the other way too.. that a large percentage of the population alive today can count rulership/prominence in their ancestry. I speculate that when times were hard for humans in the course of history, those who were better off were more likely to successfully raise kids to adulthood, who in turn had better chances of establishing their own families

irrational 4y ago
Yes, every single person alive that has any ancestry from Western Europe is a direct descendant of William the conqueror and Charlemagne and others. But they are also all direct descendants of the servant who cleaned out their potty every morning (presuming that servant had descendants). Claiming royal descent is not a big deal since we are all descended from everyone that lived back then and has descendants to this day. https://waitbutwhy.com/2014/01/your-family-past-present-and-future.html https://waitbutwhy.com/2014/01/your-family-past-present-and-... https://nautil.us/youre-descended-from-royalty-and-so-is-everybody-else-236939/ https://nautil.us/youre-descended-from-royalty-and-so-is-eve...

irrational 4y ago

You should read up on family trees. This is an extremely well known thing and you can find a lot of articles that answer this question.

bin_bash 4y ago
This comment is begging for a link—or at least a description of this "extremely well known thing"
- irrational 4y ago
  https://waitbutwhy.com/2014/01/your-family-past-present-and-future.html https://waitbutwhy.com/2014/01/your-family-past-present-and-... https://nautil.us/youre-descended-from-royalty-and-so-is-everybody-else-236939/ https://nautil.us/youre-descended-from-royalty-and-so-is-eve... https://sci-hub.st/10.1038/nature02842 https://sci-hub.st/10.1038/nature02842