Family trees: Tracing the world's ancestor
bbc.co.uk
bbc.co.uk
http://en.wikipedia.org/wiki/The_Ancestor%27s_Tale
It looks at a list of different species and then considers the most recent common ancestor we have with that species - fascinating stuff.
It's like skiing in the trees; if you want to succeed at this, focus on the spaces between the trees, not on the trees. Dawkins, for whatever reason, is distinctly focused on the trees.
No downvote here, but science "allows for" [sic] whatever IS. It's a bit above our pay grade to say what can't be; for all we know, magic might be a black swan [1].
A black swan event is merely the occurrence of a highly improbable event. That says nothing of the event's explicability.
Edit: more accurate to say science cannot explain true magic, if there were such a thing.
What's the difference between many religious concepts of gods and an extraterrestrial civilization that (at least on our scale) appears immortal, omniscient and all powerful?
Asimov's The Last Question illustrates the point pretty well:
Two major differences:
1. Evidence. Extraterrestrial life is definable and testable. "God" by most definitions is unknowable, and most religious definitions of "god" and his/her/their/its work are contradictory to scientific evidence.
2. Purpose. Nobody has committed genocide in the name of extraterrestrial aliens, but religion has been used to justify all manner of atrocities.
In other words, the first assertion includes everyone, including ALL religious people, and the second premise doesn't follow from the first anyway. Furthermore, the argument doesn't even answer the question between the differences between aliens and deity, because you are focussing on the religious movements and not the omniscient god!
All around, a poor effort.
We do not know, as of yet, what, nor how many things are fundamental to the universe.
(It's really good btw. I would recommend it to any theist.)
How far do we have to go until we reach our common ancestor with the chimpanzees? It is a surprisingly short way. Allowing one yard per person, we arrive at the ancestor we share with chimpanzees in under 300 miles. We have hardly started to cross the continent; we are still not half way to the Great Rift Valley. The ancestor is standing well to the east of Mount Kenya, and holding in her hand an entire chain of her lineal descendants, culminating in you standing on the Somali beach." http://tabish.freeshell.org/animals/human-chain.html
But reality doesn't work that way. Human population groups breed within themselves. Mating pairs are not chosen at random from the entire human population. Consider all the remote groups that would have to be covered to satisfy the assertion. Someone alive today would have to become a common ancestor of every Lapp in Finland, every Aborigine in Australia, every Inuit in Nunavut, every Maori of Polynesia, every Falklander, every North Korean, and countless more groups that barely have any contact with the world community, let alone interbreeding. (And maybe we'll actually launch a Mars colony or interstellar generation ship, literally making it impossible.)
The article does mention this very offhandedly, inserting the clause "If people in this population meet and breed at random". But that antecedent is plainly false so the conclusions are not defensible.
You are correct about mitochondrial DNA.
These claims were made by an entertaining article written 10 years ago in The Atlantic, "The Royal We," which covered the mathematical study of genealogy and is a good companion to the BBC piece: http://www.theatlantic.com/magazine/archive/2002/05/the-roya...
"Just as we are descended from most of the people alive on the planet a few thousand years ago, several thousand years hence each of us will be an ancestor of the entire human race—or of no one at all."
AFAIK "Eve" is not what we are talking here - that is not as identifying one person who is the ancestor of all living people, but that if we go back to the time of David, then he, and 80% of everyone alive at the time (approx 1 million) MUST be ancestors of everyone alive now. That is some of his DNA and some of everyone elses DNA at the time is in me.
That is pretty weird.
The other thing that gets me is that till agriculture, it seems human population was stable at around 1 million. Then it started to grow to 1 billion by 1800. Freddie Mercury could sing to the whole population of earth in three concerts.
But of course if you're descended from her, you're descended from her parents, and her mate's parents too; nobody came from just one person. Each one out of our millions of common ancestors is an Adam or Eve by the popular definition: Every human being alive is descended from them. If they had not conceived, no one currently alive would exist. There was never a biblically singular Adam and Eve.
But the earliest ancestor (female / male / mixed lineage) was only 3000 years ago.
(i.e. the first, had to have daughters only, the second, more recent could have daughter then grandson then great-grandson etc)
So, 3000 years before we can say anyone definitely was the ancestor of all, and there would be a lot of them. And 100,000 years before its female lineage. Then pretty much everyone is a common ancestor, back to plankton. And Dinosaurs!
Also, with a population of 1 million people a female line 'wining' is much more likely than with a ~6 billion people population that probably will not happen again for a vary long time without some awesome mutation.
I think that's a typo, should be: "...first woman every human...". All of us have Mitochondrial Eve as our matrilineal MRCA, not just those with two X chromosomes.
The total human population was greater than 1 million.
For me, far more interesting than who is in there is the path things took between me and that royalty.
The Old Testament / Bible allows both parents to determine Judaism in the child.
People will stop having offsprings (and even sex) well before that because they are immortal, even if they die, they can be resurrected because they have copies. Provided, human race doesn't get destroyed by itself or AI.
Its about the evolution of the human species over the next million years turning on very specific events in Ecuador in the year 1986, and the common ancestor of all future humanity.
In his unique style, of course.
Of course, if you can father hundreds of children, that would also work. But you would probably run a much higher risk of being killed or imprisoned before you can spread your genes around much.
Get busy.
The only reason having more children might be beneficial is if it significantly increases the odds that they personally, or their children successfully reproduce. If you have some other way of boosting those odds -- say, by being a successful parent to a smaller number of children -- that's just as good in the long run.
What determines if you are a common ancestor is the particular genes you carry: do they give the carrier enhanced survival benefits? I can see someone like Kobe Bryant or Brad Pitt being a common ancestor.
Edit: thinking about it more, there is something you can do: have as many children as you can with as many genetically diverse women as possible. The key here is diversity, you want to pair your genes up with as wide a range of genes as possible. The reasoning is that we can't predict what environment will be exerting selective pressures in the future. Thus the important factor is genetic diversity. This is basically hedging against unknown changes in the environment.
Also, teach your kids to not be racist, so that they will do the same and pass that tendency onto their kids...
The human genome has only 20,000 protein-coding genes (which comprise 1-2% of human DNA). I'll be generous and use the 1% figure to assume that human DNA has about 2e6 "genes" (protein-coding or otherwise).
After 100 generations:
Probability any one gene comes from MRCA: 1/(2^100). Probability any one gene does not come from MRCA = 1 - 1/(2^100) Probability NO gemes come from MRCA = (1 - 1/(2^100))^(2^6) = 0.9999999999999999999999999999495129020658552444536494
Probability at least one gene comes from MRCA = 5.05 × 10^-29
There is probably only a few percent of variation between all of your 2^100 ancestors genomes (the majority of whom will be related), so protein coding regions of your genome and your MRCA are actually likely to be very similar.
Now if that MRCA had a specific mutation, the chances of your inheriting that specific mutation are probably low, but depend on that mutations prevalence in the population as well as whether the mutation is deleterious or not.
100 generations is very few in terms of changes within the genetic make up of a population under normal circumstances.
If you think about it, its very nearly 100%. The fact that he is the MRCA means that a particular gene of his conferred an enhanced survival advantage. This enhanced gene is likely to exist in all of humanity currently living.
This really threw me for a while, as it seemed to be an obviously false statement. Until I realized the author had switched contexts on me: Jesus claimed male ancestry, but this statement is including ancestry from both male and female lines. So it seems overall believable, however I still see many provably false assumptions in this article.
* The population of the Holy Land was a constant 1 million people for 35 generations. Assumes no population growth. (false)
* No imigrants (false, see next bullet)
* No intermarrying with other cultures (false, because this intermarriage is often cited in the Bible as a reason people turned to other gods)
> More specifically, imagine the simplest case of a population of a constant size - say a million (the approximate size of the Holy Land at the time of Jesus).
I'm just quoting this to show that the author asks us to assume a constant size population
I'm certain that there were thousands of people in Palestine that could have claimed an unbroken ancestry from David. But based on all the flaws in this article, I don't trust the assertion that everyone in the area can claim an unbroken line (even including female ancestors).
The problem is, different people have different life span. And different people can share the same parent.
And sometimes in extreme cases, father - daughter love?
"Studies have used computer modelling to estimate that the MRCA of modern humans lived between 5,000 to 2,000 years ago."
Person Who Will One Day Become Warlord-Ruler Of What Was Once Nebraska Born In Omaha Hospital
http://www.theonion.com/articles/person-who-will-one-day-bec...
Seriously though, what about if you marry someone from a different country? I'd imagine the chances are somewhat lower.
Well, some of us are.
The title is very misleading. It's not true about any single person, unless there's a species bottleneck with only one survivor, and then there's a practical problem.
It would be more accurate to say that all those living 3000 years from now will have their genetic roots in all those living in the present. But if that had been the headline, no one would read the article.
How about this: "In 3000 years everyone alive today will be the common ancestor of all humanity". True, but not very exciting.
The title -- "In 3000 years someone alive today will be the common ancestor of all humanity" -- is not accurate. There was no single "common ancestor", because modern humans owe their genetic inheritance to multiple sources. This will be true in the future as well.
The title clearly suggests a single ancestor, an individual.
From the story: "In fact about 80% of the people at that time in the past will be the ancestors of everyone in the present. The remaining 20% are those who have had no children, or whose children have had no children, and so on - in other words, people who were genetic dead-ends."
This puts a whole new perspective on the often quotes statistics about Genghis Khan's progeny.
At least until full blown reproductive genetic manipulation comes into effect.
The common ancestor would probably have to be the ancestor of a very successful nation that would rule (a big part of) the world, and no current world ruling nations let their governors reproduce at will, like they did in the past.
Currently the world is full of Genghis Khan descendants, but also, there are no Genghis Khan equivalents anymore.
Simply remember the Monika Lewinsky scandal.
A few thousand years after that, 80% of us (those who leave children who in turn leave children, and so on) will be ancestors of all humanity. What an inheritance!"
Probability your parents are the same person: 0
Probability one of your grandparents is the same person (i.e. your mom's mom is your dad's dad's wife): very low
But then you get up to the point where you have 10k or 10m ancestors and those numbers start to skyrocket.... especially given how relatively geographically constrained we are.
So if you go back 3000 years, you'll have whatever 200 million (whatever the global population was in 2000 B.C.) ancestors. But that number will be chock full of "repeats". In fact you might only have 20 million "unique" ancestors in that era.
You'd need to model migration to actually figure out when you could reasonably expect that everyone would be somehow descended from you.
But even if you completely buy in to the premise of the article, they still get the analysis wrong.
It's not that someone will be the common ancestor, it's that everyone¹ will be a common ancestor of all humanity.
¹ who breeds and whose children breed, and their children breed...
Yes, that's actually stated very pointedly in the article.
Picture: http://news.bbcimg.co.uk/media/images/62401000/jpg/_62401882...
"In fact about 80% of the people at that time in the past will be the ancestors of everyone in the present. The remaining 20% are those who have had no children, or whose children have had no children, and so on - in other words, people who were genetic dead-ends. [...] A few thousand years after that, 80% of us (those who leave children who in turn leave children, and so on) will be ancestors of all humanity. What an inheritance!"
I am curious when the most recent unique common ancestor of humanity existed. Would we consider him human now or something in between?
That would be nice, but it doesn't reflect reality. In schools, children are frequently given autism spectrum diagnoses against their better interests, or wishes, or the wishes of their parents (but not always -- sometimes parents force these things on their children). But the patient's wishes are often the lowest priority.
Ideally, people would volunteer for therapy solely on issues they choose for themselves. But this isn't how clinical psychology works in modern times. Schools have a vested interest in getting diagnoses, because special-education funds are only available for those with a diagnosis.
The reason Asperger's is being abandoned is because it was applied in exactly the way described above, until everyone realized it was a scam -- even the therapists who benefited the most. Now it's slated for removal from the next edition of the DSM, and further, the diagnosis criteria for autism spectrum is being reworked to prevent another epidemic of nonsense diagnoses such as we have just seen.
> The odds that you receive a psychiatric evaluation against your will and be compelled into therapy are amazingly slim.
On the contrary, it's an everyday occurrence, especially among children, who aren't mature enough to realize that psychologists aren't doctors.
> Especially for something like 'autism-spectrum' disorders, where the majority of sufferers appear to be high-functioning.
Yes, and that is the present problem area -- bogus diagnoses, using vague criteria that can be applied to nearly anyone, with obvious advantages to everyone except the patient.
Mental health professionals, aware that autism spectrum diagnoses are out of control and no longer have any connection to reality, have joined an American Psychological Association task force charged with redefining ASD to stem the tide of nonsense diagnoses. One of those behind the redefinition effort (Dr. Fred Volkmar, director of the Child Study Center at the Yale School of Medicine) says of the diagnosis surge, "We would nip it in the bud."
REALLY??! Wow. I sure thought I was seeing a bunch of misguided hullabaloo, but I'm surprised to see the "industry" itself is aware of it and addressing it. Do you have a link or any kind of substantiation?
http://www.nytimes.com/2009/11/03/health/03asperger.html?pag...
The above is just one of the many links to this topic -- here's another:
http://www.npr.org/2010/12/29/132407384/whats-a-mental-disor...
It's important to say that DSM-V (the new edition of the diagnostic manual) is being compiled in secret, contrary to the open nature of science, and demonstrating that the psychological community are circling the wagons against what is certain to be a storm of criticism once it's published (slated for May 2013).
One of the tidbits that has slipped out of the secret process is that grief over the loss of a loved one will qualify for a depression diagnosis, which will allow the prescribing of drugs to treat this new "mental illness."
Further reading: http://arachnoid.com/trouble_with_psychology
>Asperger’s syndrome... will be folded into a single broad diagnosis, autism spectrum disorder
Not really. Two things are happening:
1. Asperger's is being dropped as a diagnosis.
2. ASD diagnostic criteria are being redefined with the specific aim of reducing the number of diagnoses, to avoid another epidemic of nonsense treatments of people who, apart from being intelligent, are otherwise normal.
Further reading: http://www.nytimes.com/2012/01/20/health/research/new-autism...
> There are definitely things behind AS ...
Yes, there certainly are. It's a gold mine for clinical psychology, because anyone to the right of the mean population I.Q. can be diagnosed using the present criteria, and because of this kind of abuse, it's being abandoned -- it's just too tempting to apply it to everyone. As one of its prominent critics has said, "It's not an evidence-based term."
http://www.nytimes.com/2012/01/20/health/research/new-autism...
Dr. Volkmar --who you quoted-- is actually against the redefinition and is arguing that the redefinition hides people who do suffer from genuine conditions.
Here is a Yale interview of Dr. Volkmar that left me with a far different impression than the NY Times article:
http://yalemedicalgroup.org/autism2012
And this:
http://www.yaledailynews.com/news/2012/feb/02/autism-redefin...
So that would be why Volkmar is serving on a task force charged with responsiblity for redefining ASD? That would be why he has been quoted as saying his committee would address the ASD diagnosis epidemic and "nip it in the bud"?
http://www.nytimes.com/2012/01/20/health/research/new-autism...
Quote: "The changes would narrow the diagnosis so much that it could effectively end the autism surge, said Dr. Fred R. Volkmar, director of the Child Study Center at the Yale School of Medicine and an author of the new analysis of the proposal. “We would nip it in the bud.”" (Emphasis added.)
To make this perfectly clear, Dr. Volkmar is an advocate of this change, and is one of the leaders of the activity.
Further reading: http://www.nytimes.com/2009/11/03/health/03asperger.html?pag...
You're being incoherent--why on earth would psychologists "abandon" a diagnosis that they "love" because it's "bread on their table"?
On second thought, don't bother answering--I already waste too much time jousting with conspiracy theorists on HN.
That's like saying astrology is being reclassified as a form of astronomy. Something like that happened, but we all know the outcome of that battle.
> why on earth would psychologists "abandon" a diagnosis that they "love" because it's "bread on their table"?
Because of public exposure. Because of articles like this one:
http://arachnoid.com/trouble_with_psychology
Psychologists realized their behavior was obviously and solely self-serving, even to non-specialists. So, just as with Recovered Memory Therapy, they called a halt to something that could only do them more harm.
> I already waste too much time jousting with conspiracy theorists on HN.
That only makes sense if psychologists are the conspiracy theorists, because it is psychologists who are demanding this change. Case in point -- Theodore Insel, sitting director of the NIMH, calls for the same change that I do:
http://www.scientificamerican.com/article.cfm?id=faulty-circ...
Quote: "In most areas of medicine, doctors have historically tried to glean something about the underlying cause of a patient’s illness before figuring out a treatment that addresses the source of the problem. When it came to mental or behavioral disorders in the past, however, no physical cause was detectable so the problem was long assumed by doctors to be solely “mental,” and psychological therapies followed suit.
Today scientific approaches based on modern biology, neuroscience and genomics are replacing nearly a century of purely psychological theories, yielding new approaches to the treatment of mental illnesses."
Sound familiar?
Tell that to Dr. Insel, sitting director of the NIMH, who I quoted to make my point.
Adam and Eve were (and I guess Noah?)
The large majority of modern historians agree that Jesus existed and regard events such as his baptism and his crucifixion as historical.