All one family ?

Question

I personally find it hard to accept the idea that we are all one family. We are barely able to trace our individual ancestors back more than 2,000 years. Homo sapiens in their present form have been around for at least a million years, so that leaves a big gap of unknown, that people tend to fill with fable and speculation, rather than admit that they simply don't know.  There is no evidence that humans sprang from a single group, but more likely a mixture of groups, even today people show traces of neanderthal genes, indicating that they did not become extinct, but rather an amalgamate of several types.

Our recorded history is but a minuscule fraction of the story of humanity.

Comments

Our recorded history is but a minuscule fraction of the story of humanity.

asked by Tim Perry

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That's why archaeologists call what came before "pre-history", even though in some areas "pre-history" is contemporary with recorded history.

Humans.   The weirdest lifeform on the planet.   

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Have you read the Seven Daughters of Eve? It's an eye opening look at mitochondrial DNA and how it says we're all connected.

Answer 1

Tim, you may find this article an interesting read.

So you’re related to Charlemagne? You and every other living European…

I think the same principles would apply to everyone of any descent--go back far enough (and it really doesn't have to be to pre-history--and the statistical odds are that we all share at least one or more common ancestors. Furthermore, "All human beings are 99.9 percent identical in their genetic makeup." Another fact which would make it (almost?) statistically impossible that you don't have at least one ancestor, but most probably more ancestors than you can imagine, in common with every other human.

Genetics vs. Genomics Fact Sheet

Comments

If we look at trees in a jungle, over time they slowly evolve to have similar leaves. This does not mean they are hybrids, but being exposed to the same environment, they develop to best suit the conditions they are in. Same thing with animals, and humans. If a population is in a certain environment, they will evolve in a predictable manner, ie, their DNA will be very similar, but it does not mean they are related, just that that is the best format for their survival.

Answer 2

Simple math: the number of ancestors you have doubles with every generation. Charlemagne (for a frequently used example) would be about 40 generations away from someone alive today. In 40 generations, the number of potential ancestors one has is over one trillion, which far exceeds the number of people who have ever lived, let alone the number of people who were alive in AD 800. If one has entirely European ancestry, then one is necessarily descended from nearly everyone alive in Europe who left descendants to the present, and not just once but many times over.

Comments

So, you would say that a northern Inuit is related to an Australian Aborigine ?

Consider the Egyptian Pharohs, they practiced incest, brothers married sisters, and in relatively few generations genetic defects presented themselves. If the human race had done as you say, for thousands of years, we would be extinct by now. That would be eugenics on a massive scale, resulting in sterility, deformity, and genetic stagnation.

Or view it from another angle, we have to try our best to keep data accurate, using verifiable proof. As I said, it's hard enough to prove 2,000 years, just a few generations, yet folk claim common ancestry from tens of thousands of years back. Where is the verifiable proof ?

Quoting a book written by men with an overt political/social agenda is hardly proof, people lie to suit their purpose. As a small child I read about Noddy and Big Ears, yet I don't expect to meet them.

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Here was the first big paper towards proof, although not without controversy:

https://www.nature.com/articles/325031a0

Many, many other scientific articles continue to support the notion that we all have common ancestry not too long ago.

The human race was never as small as a nuclear family of pharaohs. It doesn't take much genetic diversity to avoid the problems of incest and deformities. It's a false analogy comparing human history to that of a single inbred family.

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So, you would say that a northern Inuit is related to an Australian Aborigine ?

If you are a creationist then you believe that all men and women descend from Adam and Eve.  So, yes, the Inuit and the Aborigine are related.

If you are an evolutionist, Aboriginals broke off from the group of Africans who crossed to Egypt some ~ 50,000 years ago.  Again, both come from the same original group and are thus related.

Those who migrated to Australia and others who migrated to Europe have been genetically isolated from each other for longer periods.  And it is no surprise that the biggest differences we see are from those who have been genetically isolated for longer time periods.

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It is unrealistic to describe our history as a tree of ancestral populations, with the first leaving Africa and other groups splitting off. As Tim said, there has been constant mixture of groups that have already been separated. So that, for instance, a study of genetic diversity showed that Native Americans and Europeans are more closely related to each other than Native Americans are to East Asians. The "splitting off" model doesn't account for that. Instead, over tens of thousands of years, there have been many different populations that are ancestral to the existing populations but have no corresponding existing population today. The "Ancient Northern Eurasians" (ANE) were a group who lived in central Siberia maybe 20,000 years ago. Some of the ANE headed east and together with the people who had already lived in east Asia for tens of thousands of years form the ancestral population to modern Native Americans. But another group moved west and eventually became Ancestral to the Yamnaya culture and also to hunter gatherers in Eastern Europe. When the Yamnaya swept through Europe, the ANE became ancestral to a large chunk of the European population.

And then in dating the common ancestor of all mankind to just maybe 2500 years ago, it's not so much the early splitting of populations that accounts for a pretty recent common ancestor. It's the rare long migrations of single individuals. When one person leaves a continent and arrives on another, then has a growing collection of issue there, those descendants will eventually admix with a substantial portion of the existing population, and a small trickle of them will also undertake large migrations themselves. This takes a while. The major European arrival in the America's after Columbus was too recent to change the time to a most recent common ancestor by much -- it's estimated to have moved the time forward by only maybe 2-3%. Even including a extremely slow trickle of Vikings to Greenland from 1000-1350 CE another  trickle of South Americans to Oceania around 400 CE only pushes the time forward by less than 10%. So the main reason Native Americans and Austronesians have a common ancestor only 2,500 or so years ago is because of the slow trickle of people migrating through the Bering Strait, which has been happening continuously through the last few thousand years back to our most recent common ancestor. When you trace your line back to this ancestor, you will definitely have some "super-migrators", and most native Americans would have some who made the Bering Strait passage.

This paper describes the famous simulation:

http://www.stat.yale.edu/~jtc5/papers/CommonAncestors/NatureCommonAncestors-SupplementB.pdf

But it is only a simulation, and if you read what they did it might come accross as people playing a game of Sim City, not doing real science. "Fable and speculation," as Tim put it. Fortunately, there is a growing body of data on human genetic diversity, both of modern humans and ancient humans, that is roughly supporting the results of the computer simulations.

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"It is unrealistic to describe our history as a tree of ancestral populations..."

Genealogically speaking, it is "unrealistic" to attempt genealogy going back more than 400 years in >99% of cases.  And going back more than ~ 1500 years is (as of yet) impossible.  Tim posed posed the question if two groups of people are related.  Yes, they are.  How related or not is way outside of the time period of the study of genealogy.

Answer 3

>> We are barely able to trace our individual ancestors back more than 2,000 years.

Nobody can reliably trace their ancestors back 2,000 years. For almost everyone, going back more than 500 years is nearly inmpossible.

>> Homo sapiens in their present form have been around for at least a million years...

Homo Erectus was, and we might descend from them. But anatomically modern humans came around more recently -- maybe 200,000 years ago or a little more.

>> So that leaves a big gap of unknown, that people tend to fill with fable and speculation. 

I know of almost nobody who fills the gap between 500 years ago and 200,000 years ago with fable and speculation. Rather, the speculation is filling the gap from 100-200 years ago back to 500 years ago, when they can finally claim some noble or another that they descend from.

>> There is no evidence that humans sprang from a single group, but more likely a mixture of groups, even today people show traces of neanderthal genes, indicating that they did not become extinct, but rather an amalgamate of several types.

You need another adjective. There is lots of evidence that all living members of our species descend from the same ancestors not too far in our past. But if you look at ancient human specimans, you would have to go back much farther to find a common ancestor. For instance, because it is now known that anatomically modern humans interbred with Neanderthals, so we are (arguably) of the same species, you would have to go back much farther in time to find a common ancestor between yourself and some ancient Neanderthal specimen.

>> Our recorded history is but a minuscule fraction of the story of humanity

That is true. There were huge populations of humans that we know almost nothing about. 20,000 years ago, the genetic diversity of humans was as broad as it is today, but along totally different clines of variation. The history of humanity is not a tree but rather a story of constant migration an intermingling, followed by isolation into genetically distinct population groups, followed by further migration and intermingling. Throwing another wrench in -- sometimes cultures would only adopt the language or customs of their neighbors without becoming genetically intermingled. Archaeogenetics, anthropology, and archaeology are a fascinating collection of fields.

I recommend David Reich's book Who We Are And How We Got Here if you like this stuff.

Comments

None the less, Barry, that does not prove that I am related to individuals A, B, or C. We are supposed to be dealing with proven facts, are we not ? There is no evidence that I have not descended from a separate, entirely different group, so it must be wrong to claim that we are all related.

I personally believe that every race should be proud of their heritage, to celebrate our differences, it is that divergence within our species that is our greatest strength. If we were all identical, then the next plague or pandemic would wipe us all from the face of this earth, there would be nothing to stop it.

I am not a creationist, it is proven that a gene pool that small is not viable. There is also the question raised by another on here, Adam's sons were said to have taken wives. Where from ? their mother ? sisters ?, or did they breed with apes ?.

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I already linked to you the first main form of evidence: the 1987 mitochondrial DNA study. There are also Y-DNA studies and studies of ages of segments of autosomal DNA. All of these studies confirm the same theory.

You are demainding that the only form of proof be documented relationships, but 

1. documents lie, and
2. a documented trail is still just evidence supporting a theory

Nobody has "proof" that they are the child of their own father. But a birth certificate and a paternity test are very strong evidence in support of it. Similarly, you keep repeating "there is no evidence" when I have given you two scientific studies that provide that evidence. And many other scientific studies now support the recent common ancestor theory.

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Correction, I did not mention documentary evidence.

As you say, people 'manipulate the facts' to support their opinions.

Scientific studies are not immune to economical use of data, they are written by people, with all their fallibilities. History is littered with the writings of those that claim to know all the answers.

It is fair to say that there is no proof positive of any line of descent. Even if a woman gives birth, the child could be from a donor embyro.

All this is evading my basic point, that we cannot make reasonable claim to ancestors that is not proven.

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Fine, you did not. But I did not say anything about "manipulate the facts", so I guess we are both guilty of the same sin. While you did not specify what kind of evidence you are interested in, it seems you still have not read the papers I linked that do provide positive evidence of common descent from a common ancestor who lived since the arrival of anatomically modern humans. That proof is not in the form of a proof of a specific lineage. Since that is what you are requiring, I assumed you would get there by documentary evidence, since no other form of evidence is yet known that can identify a specific lineage going back centuries. That is why I inferred that you were referring to documentary evidence. What other kind did you have in mind?

Mitochondrial DNA and Y-DNA studies *do* provide positive proof of common descent, without telling you the specific line of descent.  As do other more modern studies of autosomal DNA.  It is not a requirement to prove common ancestry that you prove specific lines to the ancestors, and yet that is what you are claiming.

Here's another example: if you test your Y-chromosome and you are a very close match to someone else, you can be assured that you have a common recent paternal ancestor. No one disputes that. But the Y-DNA can't identify exactly who that ancestor was and which line you came down. (Although the BigY test is making this more feasible.) It's the same thing with the genetic studies of human history and population migration, which are partially supported by archaelogical and anthropological evidence. You can't determine a specific line -- heck, we don't even have names or other ways to identify the individuals who might be in those lines. But you can still be assured that there is a common ancestor and in a reasonably specific time frame.

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No one is disputing that we have predecessors, otherwise we would not be here to debate. However, if you tried to create a profile like this -

Surname - unknown. First name - unknown. Location - unknown. Son of - unknown and unknown. Siblings - unknown. Spouse of - unknown. Marriage date - unknown. Place - unknown. Children - unknown. Death - unknown.

Sources - unknown, yet to be proven.

There would be almost instant outcry, yet that is in effect what the "all one family" concept proposes, and I don't think this can possibly be correct.

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"All one family" includes marrriages, not just tracing back to a common ancestor. Nobody here believes we will all have profiles connected back to one ancestor someday. One goal is to strive towards that ideal as much as possible. But people also enjoy seeing their connections using the connection finder, which will go through several marriages, if necessary.