> However, even with the DNA "dissolving beyond recognition" in five generations, traits can be passed on beyond that. I understand that there are traits in modern day France and Iran that indicate Hun and Mongol ancestry respectively.
Yes, sorry, I didn't put it well. What I meant to express was rather that genetic data and ancestry do not necessarily have to match up. To see a measurable genetic impact many generations later, you'd need some "substantial" (whatever that is) amount of migration. Either a steady trickle over a long period of time, or a large amount of migration at one point of time. In contrast since ancestry is - by definition - never dissolves, even a single individual at one point of time is enough to pass it to a large population after several generations. So, of course, genetics and ancestry are interrelated (and very closely for most practival purposes). But in this particular case, they may diverge, and this would not necessarily disprove the theory.
The article does not make such an assumption (no folding). Indeed the point is addressed explicitely (along with several others).
Also, keep in mind it's not taking about genetic inheritance, but family trees. There may be next to no genes left in you from your great-great-...-grand-father, but he's still 100% your ancestor. Hence genetic diversity and common ancestry lines are not at contradiction.
Most likely you've heard the quote "God does not roll dice", attributed to Albert Einstein. Maybe a year ago or so, I came across this quote on a Creationist propaganda site. Needless to say, I was highly angry about them misusing this quote so entirely out of context - especially since Einstein was prominently and strongly opposed to religious "reasoning".
Why am I reminded of this just now? Well, to me you seem like someone shouting "Well damn that bloody Creationist Einstein, then!" I guess, if Einstein had had a premonition of the Creationist nonsense to come after his day, he might have chosen different words (and after all, he was wrong about quantum mechanics anyway). Barring that, I'd rather blame the Creationist propagandist for misusing the quote, than Einstein for coining it. In fact, I think, much more is to be won in pointing out the quote is entirely out of context than by debunking it, thereby "admitting" it was meant to support the notion of the Creationists.
Can you see the analogy? Well, in case not, I guess it's because our disagreement is really rooted somewhere else: You think the research itself is driven by propaganda and flawed. I think it is not at all driven by propaganda, seems scientifically sound, and does not give the slightest support a Creationist point of view at all.
If your point actually was "Well, the original study is pretty nice, but I think the article about it makes a number of superfluous, misleading, and maybe even dangerous statements that should really be critized, for they could lead to a wrong interpretation" - fine, I'll give in, tell you have a point, even though I don't think it's really all that bad. However, I'll also tell you, you did not differentiate well between the research, and it's popularized presentation, and I got the impression you were actually after something different.
If your point actually was (as I understood it to be) "The research itself follows a Creationist agenda, it is scientifically flawed, and no one should ever have written an article about this crap", then I prefer to disagree. I think I have addressed the main points of criticism you have raised regarding the methodology of the study. Feel free to debunk those defences in turn, but obviously we've already strayed far away from that discussion.
Maybe I just got you wrong, but then please help me find out, where we really disagree.
> Your job is that much easier with me out there doing the dirty work.
Until that time, however, letting you do the dirty work - or so I'm worried - is setting a fox to keep the geese.
> I would like to see the statistics backed up with more actual genetic data, but the study is interesting, at least.
Don't mix up genetics and ancestry. The genes of a person from 100 generations ago would be entirely dissolved and not measurable today. This person could only pass on 1/2^100 of his genes to any particular person living today. That's technically nothing at all. Ancestry is an entirely different story, and really more of a mathematical concept: This person could still be 100% your ancestor, as ancestry is just defined that way.
So 1) genetic data does not help much with this at all. 2) Passing down your ancestry/family tree is much "easier" than passing down your genes. That's an important part of the reason why the result is plausible indeed, even taking isolated populations into account.
Come on, now. There may be lot's of religious zealots and zealotry out there, but it does not mean every person you meet, and every article you read is one of them. For the record: I'm an atheist, I believe in evolution theory, my adrenaline level rises dramatically, when I read creationist propaganda (or even just about it). Ready to listen more carefully, now?
So the article starts out with dramatic inexact wording. Criticise that, all right. But realize most articles do. Read on to see whether it remains that way, just like you click the link after reading a sensationalist slashdot summary. I'll give you some further quotes, not that much further down:
"Had you entered any village on Earth in around 3,000 B.C., the first person you would have met would probably be your ancestor," Hein marveled.
[...]
As the number of potential ancestors dwindles and the number of branches explodes there comes a time when every single person on Earth is an ancestor to all of us, except the ones who never had children or whose lines eventually died out.
And it wasn't all that long ago. When you walk through an exhibit of Ancient Egyptian art from the time of the pyramids, everything there was very likely created by one of your ancestors every statue, every hieroglyph, every gold necklace. If there is a mummy lying in the center of the room, that person was almost certainly your ancestor, too.
How's that for Adam and Eve? BTW, it's right after that paragraph that the "Abraham thing" is mentioned. And in that context "It means when Muslims, Jews or Christians claim to be children of Abraham, they are all bound to be right." does sound a little spiteful to me. Didn't you notice at all, do you think the author did not place it there on intent? Being a "child of Abraham" can be mathematically shown to be a null-statement. And it can additionally be shown they're children of the ol' evil pharao at the same time. Oh, the irony.
On inbreeding: No, you didn't propse any new insights on that. The article did, which is why I asked you to first read the article again, then go bashing:
[...] Imagine there was a man living 1,200 years ago whose daughter was your mother's 36th great-grandmother, and whose son was your father's 36th great-grandfather. That would put him on two branches on your family tree, one on your mother's side and one on your father's.
In fact, most of the people who lived 1,200 years ago appear not twice, but thousands of times on our family trees, because there were only 200 million people on Earth back then. Simple division a trillion divided by 200 million shows that on average each person back then would appear 5,000 times on the family tree of every single individual living today.
I apreciate you don't want to waste your time on the local cleric, and in fact, I don't plan to either. I do take delight in picturing how he might react, though. Maybe you can too (but no, the joke's not funny any more after explaining it:-( ). Either way, if you'd like to help the cause of enlightment, please focus on helping those understand the actual message of this research that would otherwise think it acutally supports a creationist view of the world. It does not.
One more concluding remark on the "isolated populations" you mentioned in your orignial post. Guess why they're not a problem in the study, even though they we're taken into account? Because the authors did not search for the "beginning of time" or some such. They say, all of their population today has a Greek/whatever ancestor 5000 B.C., because a single migrant visiting them in 1356 B.C./whenever and having children is enough to bring his entire family tree into that population. That migrant did not cause the Amazon tribe to exist, did not influence their gene pool in any way measurable today (100+ generations later), but he did - technically - bring in his entire ancestry. Beautiful maths.
My "common sense" was rebelling as well, until I figured out I used the wrong model of thought. This is not about genetic relatedness. It's about family trees. You may have only inherited a 1/2^40 fraction of your great-[37 more "great"s]-grand-father's genes (which is probably less than a single base pair!). But he's still 100% your ancestor. Genetic inheritance and ancestry are two entirely different concepts.
This also explains the thing about "corners of the gene pool that just don't mix very much". They don't need to for the concept of ancestry. A single migrant is enough to hand down his entire family tree to an entire population, while their DNA is quickly dissolved in the local gene pool.
But the real agenda here is to say that our "common ancestors" were Adam and Eve
No, this is absolutely not the point of the article, nor is it implied in any which way. Read TFA again, if you really think so. The article says that each of the millions of persons in the 5000 B.C. timeframe who had offspring are ancestors(*) to all of us. It also only gives an estimate of the latest point at which this should be true, not the earliest point. Nowhere, and in no way does the article seek to make out "the two first human beings" or try to date them.
Further, as others have pointed out, for the purpose of passing down a family tree/ancestry - in contrast to substantial genetic inheritance - a single migrant ever coming to an "isolated population" is absolutely enough to "infect" an entire population several generations down the line. As an example for the difference between genetic inheritance and ancestry: Your great-great-great-great-grandfather is just as much your ancestor as your direct father. He only handed down a tiny fraction of his genes, however.
(*): And not just once - such a person would be highly likely to be found on our family tree several times! Read the article for an explanation. Then go shock your local cleric with your new insight on inbreeding.
it appears that the point isn't "All of us have one common ancestor in the collective sense[...]"
Yes, it is, indeed. Moreover, it goes on to say "and we don't just have one common ancestor in the collective sense, but every single person in that timeframe (unless their family tree quickly died out) would have been a common ancestor to all of us. It's essentially because you have two parents, but twice that many grand parents, and twice that may great grand parents, and so on.
Also note, that this does not have to be matched with the "genetic drift model" at all. A single migrant can hand down their ancestry to an entire (previously unrelated) population within a few generations. Their DNA will be dissolved beyond recognition a mere five generations down, but the ancestry (by definition) is always handed down 1:1 and never dissolves at all. I guess it's this difference between genetic inheritance and ancestry which leads to confusion (and this confusion makes it such a surprising finding in the first place).
Which there wasn't in the timeframe the article talks about. As far as I can recall, there is strong evidence that once the ice ages ended migration into North America ceased, which was much longer ago than the article is suggesting.
Well migration != migration for this purpose. It's enough for few or even single individuals to migrate (and "infect" other populations with their ancestry), not for whole populations to relocate in this case. This also moots the point about adaptation. The migrants just mix their DNA with the DNA of the resident population, no need to wait for evolutionary adaptation.
Of course the "walking 100 yards/day" metaphor is also wrong in this respect. It's rather one person in each generation finding a mate 100 miles away or something like that.
I can't judge the accuracy of all the study's assumptions. But they did take into account different geographical areas and different levels of migration between those areas. I think one very interesting point to consider is that only an extremely little amount of "interbreeding" is needed. Suppose there's just one single migrant coming to a sizeable (stable) population of 1.000.000 (~2^20) families, and producing at least some offsprint. Within 20 generations (on average) you'd expect him to be related to each and every newborn in that population. That's no more than 500 years for a single migrant to "infect" the entirety of even a large population, no matter how isolated it is. Even if three or four distinct "hops" are needed to "infect" the entire globe, that's very likely to happen over the course of 2000 years.
BTW, contrary to the slashdot summary, the article gives 5000 B.C., not 500 B.C. as the most conservative estimate, saying 1 A.D. might still be realistic, though.
Prove it.
I suppose that's not exactly possible to do. However, on surface value, their methodology (extensive simulation testing different assumptions on migration) seems pretty sound to me.
It's not. Of course I don't know all the details of the study, but the article clearly explains it was a lot smarter than you assume. Some relevant fragments:
It's nothing more than exponential growth combined with the facts of life. By the 15th century you've got a million ancestors. By the 13th you've got a billion. Sometime around the 9th century just 40 generations ago the number tops a trillion.
But wait. How could anybody much less everybody alive today have had a trillion ancestors living during the 9th century?
The answer is, they didn't. Imagine there was a man living 1,200 years ago whose daughter was your mother's 36th great-grandmother, and whose son was your father's 36th great-grandfather. That would put him on two branches on your family tree, one on your mother's side and one on your father's.
[...]
The researchers knew they would have to account for geography to get a better picture of how the family tree converges as it reaches deeper into the past. They decided to build a massive computer simulation that would essentially re-enact the history of humanity as people were born, moved from one place to another, reproduced and died.
[...]
Allowing very little migration, Rohde's simulation produced a date of about 5,000 B.C. for humanity's most recent common ancestor. Assuming a higher, but still realistic, migration rate produced a shockingly recent date of around 1 A.D.
[...]
Migration is the key. When a people have offspring far from their birthplaces, they essentially introduce their entire family lines into their adopted populations, giving their immediate offspring and all who come after them a set of ancestors from far away.
Lot's of additional interesting tid-bits in that article. Worth a read IMO.
Not only that it's little compared to the running costs. I wonder how much of the energy required for the manufacturing is actually used for this one step. Let's do some calculations:
Heat capacity of Si at 25 C: 19.789 J/(mol*K) Too lazy to look up the heat capacity at other temperatures right now, so let's estimate it to be twice that much at 1000 C. Mass of Si: 28g/mol So that's up to 1.4 J/(g*K). Heating by 1000 K is an estimated 1400 J/g (max). How much does you average CPU die weigh? 1g? 2g? Let's assume 10 grams to be on the safe side: Energy needed per CPU in this manufacturing step: 14 kJ = 3.8 Wh.
I'll say, I'm not impressed. Sure, every little helps, but it's certainly not enough to get all excited over how "green" this new technology is. Of course, if it acutally allows to create circuits on new materials, then it's interesting news, indeed - but for an entirely different reason.
If you're asking that way, then yes, I think the one best reason to protect the environment (and I do have a long record of environmental activism) is that exploiting nature without limits will - typically only in the mid and long term - harm other human beings, ourselves, and mankind as a whole. I don't personally feel nature has a value "of it's own", although that attitude is certainly generally benefical.
But actually that's not the discussion I meant to initiate at all. Rather my reasoning goes something like this: Given that the effect occured in presence of mere pictures of eyes (instead of real surveilance), I suspect what's causing the effect is likely rooted deep in the unconscious, and in fact probably in our genes. Our genetic code, however, has evolved (not only) over the last few ten thousands of years, and the last few hundred don't count much at all on an evolutionary scale (all that's culture, not evolution). So: Environmental concerns are most certainly not in our genes. There was simply no need for it on an evolutionary scale. Up until "fairly recently", it was entirely ok, resource wise, to exploit nature to the maximum possible. Social situations are an entirely different beast, and it's very, very likely, that we have much programmed into our genes with respect to social behavior (though I believe much less than evolutionary biologists tend to proclaim).
So when I wrote "some natural ressource which can simply be exploited" I wasn't thinking "oil field" or "rain forest" so much, but more along the lines of "that hazelnut tree over there". Just pick the nuts and enjoy, no need to worry about others.
I'm afraid, your interpretation "reminder of being watched" is probably right. However, let's not jump to conclusions too fast, and give the belief in the good in humanity another chance. The eyes may also act as a reminder of "the coffee fund is a social institution, not some natural ressource which can simply be exploited".
An interesting variation would be to test eye-pictures vs. neutral pictures vs. picture showing human beings that are not directly watching (i.e. just a prompt for a social situation, not for being watched). I'd think this last type of pictures will be less effective than the eye-pictures, but maybe still somewhat effective compared to the neutral pictures.
Suppose that consultant were to get 100 requests a week, and cannot meet them in any sort of a timely fashion without cutting into his work time
Let's set aside the question, whether this is likely at all, for a moment. But if the poor consultant really gets 100 requests a week, why doesn't he contract someone do to this for him? As someone who has "run their own business" that would seem like an obvious solution, no? In fact, should you come into this situation, I'll happily do the work for you, and I'll only charge $40/h to the people requesting the source code, too.
- your way of thinking would obligate him to become a pauper for the convenience of the GPL at the demand of people who recieved a gift from him!
You're overlooking an important point: If you are bound by the obligations of the GPL, it's because you're distributing somebody else's work, not (only) yours. Your way of thinking would mean to put whoever you received a gift from to handle the work resulting from you passing it on. In some cases this "upstream author" will have much better infrastructure for dealing with requests for source, but in some cases they might even have more trouble, or their time may be even more costly. Hence, it's entirely reasonable to say: "If you redistribute my work, then you will have to deal with the end user". Just what the GPL does.
Or use a BSD-style license and avoid the whole mess.;-)
Which is entirely reasonable, if - and only if - it's your original work, and you are not bound to respect any other author's rights. However in this case - you wrote it entirely from scratch - it really does not matter, which licence you chose. Even if you distribute your own work under the GPL, you can in no way be bound to it's restrictions. You are the sole copyright holder in this case, and so you have all the rights. The only thing you do is to tell people who redistribute your software, that they a) may do so b) only under certain conditions. One of those conditions is to tell redistributors that they should deal with the consequences of redistributing themselves, and not rely on you to do all the associated work. So it's more family time for the overworked consultant, not less. Nice, isn't it?
If the intention had been to create a judical precendent for the GPL, he would have had to do better. As is, the case failed at a much too basic level. Basically the court told him, he was not in a position to sue, no less and not much more. The judge did not even have to consider the GPL itself, hence no chanceof creating a real precedent IMO. If at all, what's been ruled on, is that it's not per se illegal to give something away for free. Big deal.
We'll have to wait until somebody else dumb enough to try to disprove the GPL in court, and smart enough to actually get the formal basics right, shows up. Daniel Wallace wasn't the one.
What is better? 20 companies devoting billions of dollars to the creation of a cure in search of profits, or 2 devoting millions in search of altruism? I put my money on the 20 to come up with something faster. For those who feel like giving money away, whether they be companies, or individuals, they are more than welcome to do so when a cure has been discovered.
Of course your point is valid. Yet, the problem behind it is valid as well: Yes, there are uneccessary deaths due to pharma-companies need to sell medication way above production cost.
So, while saying "the pharma shouldn't be allowed to make profit" obviously isn't a solution, the dilemma does not go away just like that. Maybe what is really needed for global epidemic diseases like AIDS is to look beyond purely business "the market will make it happen" solutions. Maybe the problem should really be attacked on a global scale, such as e.g. the UN offering a (large) "bounty" to whoever is first to develop an effictive medication, but at the same time preventing such a medication to be patent protected. This would still be offering a capitalist incentive to do research, but place control where it really belongs: Mankind as a whole.
And no, I'm not saying such a system could realistically be implemented any time soon. Maybe (or rather very probably so) it's a way to naive approach to a complex problem, too. But then, let's discuss alternative solutions in earnest, rather than just assuming, the world we live in was the best ever possible.
Ok, well, on second read, the numbers I cited can't be true on that magnitude. And either today my google skills are weak, or it's not quite easy to find definite figures. Anyway, I'm fairly certain, that at least on short-distance flights (~500 kilometers) air traffic needs between 50% and 100% more than road traffic per passenger-kilometer and on average. For long-distance flights air traffic becomes somewhat more efficient, as a considerable portion of energy is used during take-off. Possibly for really long distances (>5000 kilometers), air traffic may even be more efficient *per person-kilometer* than car traffic.
Yet, while my previous numbers were wrong, they are right at least in one respect: Air-traffic is evil on the short distance, as it's completely inefficient there. Air-traffic is evil on the long distance for the total amount of energy consumed on large distance journeys.
Comparing total energy consumption doesn't mean anything
True, at least on a certain level. I did, as the parent post did just that.
Compare energy use per pasenger and compare airplanes to car traffic and i'd imagine it'd look quite different
Yes, road passenger traffic is 40 tonnes of oil equivalent per 1 billion passenger kilometers. For air passenger traffic it's 1456 tonnes per billion passenger kilometers. I'm not sure, whether that's the direction you expected. (2003 prov; http://www.dti.gov.uk/energy/inform/energy_consump tion/table2_5.xls)
Planes also give off less pollution per passenger than most cars
To a certain extent planes give of different types of pollution than cars, so for some select emissions your statement may even be true. In general this is dead wrong. Planes give off much more pollution than cars, even per passenger.
all the cars in uk produce 1 tenth the emissions all the airflights in the UK produce
Don't know, whether you have any specific emissions in mind, but I'd call this statement plain wrong. Currently total airflight energy use is about a quarter of total car traffic energy use (but admittedly airflight is growing at an alarming rate). Airplanes produce more emissions per distance, and also some particularily nasty types of pollution (water vapor in high altitudes, for instance, is a greenhouse factor), but it's not anywhere near surpassing car traffic in total, yet. (energy consumption in the UK. See page 14)
On standy: Yes, in many cases it makes life easier. However there is no wrong at all in
1) informing people that standby power usage is non-zero. Note that in some cases of bad design it's even quite considerable. Some inkjet printers use 15 Watts in standby - what for?
2) Pressure manufactures to make full-power-off reasonably easy.
Yes, there are areas other than standby, where (greater) amounts of energy can be saved. But also in many, many, many cases, summing up to hundreds or even thousands of megawatts, standby is just plain useless. Standby for a TV - ok, nice feature to have, if you like. Standby for a PC / printer / CD-/DVD-player? Heck, I'm typically right in front of those, when I want to start using them. What do I need standby for? Provide me with the option, fine, but give me an easy opportunity to switch them off fully, if only to reduce the risk of fire, or the damage done if lightning strikes nearby.
Slashdot Mirror
> However, even with the DNA "dissolving beyond recognition" in five generations, traits can be passed on beyond that. I understand that there are traits in modern day France and Iran that indicate Hun and Mongol ancestry respectively.
Yes, sorry, I didn't put it well. What I meant to express was rather that genetic data and ancestry do not necessarily have to match up. To see a measurable genetic impact many generations later, you'd need some "substantial" (whatever that is) amount of migration. Either a steady trickle over a long period of time, or a large amount of migration at one point of time. In contrast since ancestry is - by definition - never dissolves, even a single individual at one point of time is enough to pass it to a large population after several generations. So, of course, genetics and ancestry are interrelated (and very closely for most practival purposes). But in this particular case, they may diverge, and this would not necessarily disprove the theory.
An enjoyable discussion, indeed! Thanks as well.
The article does not make such an assumption (no folding). Indeed the point is addressed explicitely (along with several others).
Also, keep in mind it's not taking about genetic inheritance, but family trees. There may be next to no genes left in you from your great-great-...-grand-father, but he's still 100% your ancestor. Hence genetic diversity and common ancestry lines are not at contradiction.
Most likely you've heard the quote "God does not roll dice", attributed to Albert Einstein. Maybe a year ago or so, I came across this quote on a Creationist propaganda site. Needless to say, I was highly angry about them misusing this quote so entirely out of context - especially since Einstein was prominently and strongly opposed to religious "reasoning".
Why am I reminded of this just now? Well, to me you seem like someone shouting "Well damn that bloody Creationist Einstein, then!" I guess, if Einstein had had a premonition of the Creationist nonsense to come after his day, he might have chosen different words (and after all, he was wrong about quantum mechanics anyway). Barring that, I'd rather blame the Creationist propagandist for misusing the quote, than Einstein for coining it. In fact, I think, much more is to be won in pointing out the quote is entirely out of context than by debunking it, thereby "admitting" it was meant to support the notion of the Creationists.
Can you see the analogy? Well, in case not, I guess it's because our disagreement is really rooted somewhere else: You think the research itself is driven by propaganda and flawed. I think it is not at all driven by propaganda, seems scientifically sound, and does not give the slightest support a Creationist point of view at all.
If your point actually was "Well, the original study is pretty nice, but I think the article about it makes a number of superfluous, misleading, and maybe even dangerous statements that should really be critized, for they could lead to a wrong interpretation" - fine, I'll give in, tell you have a point, even though I don't think it's really all that bad. However, I'll also tell you, you did not differentiate well between the research, and it's popularized presentation, and I got the impression you were actually after something different.
If your point actually was (as I understood it to be) "The research itself follows a Creationist agenda, it is scientifically flawed, and no one should ever have written an article about this crap", then I prefer to disagree. I think I have addressed the main points of criticism you have raised regarding the methodology of the study. Feel free to debunk those defences in turn, but obviously we've already strayed far away from that discussion.
Maybe I just got you wrong, but then please help me find out, where we really disagree.
> Your job is that much easier with me out there doing the dirty work.
Until that time, however, letting you do the dirty work - or so I'm worried - is setting a fox to keep the geese.
> I would like to see the statistics backed up with more actual genetic data, but the study is interesting, at least.
Don't mix up genetics and ancestry. The genes of a person from 100 generations ago would be entirely dissolved and not measurable today. This person could only pass on 1/2^100 of his genes to any particular person living today. That's technically nothing at all. Ancestry is an entirely different story, and really more of a mathematical concept: This person could still be 100% your ancestor, as ancestry is just defined that way.
So 1) genetic data does not help much with this at all. 2) Passing down your ancestry/family tree is much "easier" than passing down your genes. That's an important part of the reason why the result is plausible indeed, even taking isolated populations into account.
Come on, now. There may be lot's of religious zealots and zealotry out there, but it does not mean every person you meet, and every article you read is one of them. For the record: I'm an atheist, I believe in evolution theory, my adrenaline level rises dramatically, when I read creationist propaganda (or even just about it). Ready to listen more carefully, now?
So the article starts out with dramatic inexact wording. Criticise that, all right. But realize most articles do. Read on to see whether it remains that way, just like you click the link after reading a sensationalist slashdot summary. I'll give you some further quotes, not that much further down:
"Had you entered any village on Earth in around 3,000 B.C., the first person you would have met would probably be your ancestor," Hein marveled.
[...]
As the number of potential ancestors dwindles and the number of branches explodes there comes a time when every single person on Earth is an ancestor to all of us, except the ones who never had children or whose lines eventually died out.
And it wasn't all that long ago. When you walk through an exhibit of Ancient Egyptian art from the time of the pyramids, everything there was very likely created by one of your ancestors every statue, every hieroglyph, every gold necklace. If there is a mummy lying in the center of the room, that person was almost certainly your ancestor, too.
How's that for Adam and Eve? BTW, it's right after that paragraph that the "Abraham thing" is mentioned. And in that context "It means when Muslims, Jews or Christians claim to be children of Abraham, they are all bound to be right." does sound a little spiteful to me. Didn't you notice at all, do you think the author did not place it there on intent? Being a "child of Abraham" can be mathematically shown to be a null-statement. And it can additionally be shown they're children of the ol' evil pharao at the same time. Oh, the irony.
On inbreeding: No, you didn't propse any new insights on that. The article did, which is why I asked you to first read the article again, then go bashing:
[...] Imagine there was a man living 1,200 years ago whose daughter was your mother's 36th great-grandmother, and whose son was your father's 36th great-grandfather. That would put him on two branches on your family tree, one on your mother's side and one on your father's.
In fact, most of the people who lived 1,200 years ago appear not twice, but thousands of times on our family trees, because there were only 200 million people on Earth back then. Simple division a trillion divided by 200 million shows that on average each person back then would appear 5,000 times on the family tree of every single individual living today.
I apreciate you don't want to waste your time on the local cleric, and in fact, I don't plan to either. I do take delight in picturing how he might react, though. Maybe you can too (but no, the joke's not funny any more after explaining it :-( ). Either way, if you'd like to help the cause of enlightment, please focus on helping those understand the actual message of this research that would otherwise think it acutally supports a creationist view of the world. It does not.
One more concluding remark on the "isolated populations" you mentioned in your orignial post. Guess why they're not a problem in the study, even though they we're taken into account? Because the authors did not search for the "beginning of time" or some such. They say, all of their population today has a Greek/whatever ancestor 5000 B.C., because a single migrant visiting them in 1356 B.C./whenever and having children is enough to bring his entire family tree into that population. That migrant did not cause the Amazon tribe to exist, did not influence their gene pool in any way measurable today (100+ generations later), but he did - technically - bring in his entire ancestry. Beautiful maths.
My "common sense" was rebelling as well, until I figured out I used the wrong model of thought. This is not about genetic relatedness. It's about family trees. You may have only inherited a 1/2^40 fraction of your great-[37 more "great"s]-grand-father's genes (which is probably less than a single base pair!). But he's still 100% your ancestor. Genetic inheritance and ancestry are two entirely different concepts.
This also explains the thing about "corners of the gene pool that just don't mix very much". They don't need to for the concept of ancestry. A single migrant is enough to hand down his entire family tree to an entire population, while their DNA is quickly dissolved in the local gene pool.
But the real agenda here is to say that our "common ancestors" were Adam and Eve
No, this is absolutely not the point of the article, nor is it implied in any which way. Read TFA again, if you really think so. The article says that each of the millions of persons in the 5000 B.C. timeframe who had offspring are ancestors(*) to all of us. It also only gives an estimate of the latest point at which this should be true, not the earliest point. Nowhere, and in no way does the article seek to make out "the two first human beings" or try to date them.
Further, as others have pointed out, for the purpose of passing down a family tree/ancestry - in contrast to substantial genetic inheritance - a single migrant ever coming to an "isolated population" is absolutely enough to "infect" an entire population several generations down the line. As an example for the difference between genetic inheritance and ancestry: Your great-great-great-great-grandfather is just as much your ancestor as your direct father. He only handed down a tiny fraction of his genes, however.
(*): And not just once - such a person would be highly likely to be found on our family tree several times! Read the article for an explanation. Then go shock your local cleric with your new insight on inbreeding.
it appears that the point isn't "All of us have one common ancestor in the collective sense[...]"
Yes, it is, indeed. Moreover, it goes on to say "and we don't just have one common ancestor in the collective sense, but every single person in that timeframe (unless their family tree quickly died out) would have been a common ancestor to all of us. It's essentially because you have two parents, but twice that many grand parents, and twice that may great grand parents, and so on.
Also note, that this does not have to be matched with the "genetic drift model" at all. A single migrant can hand down their ancestry to an entire (previously unrelated) population within a few generations. Their DNA will be dissolved beyond recognition a mere five generations down, but the ancestry (by definition) is always handed down 1:1 and never dissolves at all. I guess it's this difference between genetic inheritance and ancestry which leads to confusion (and this confusion makes it such a surprising finding in the first place).
Which there wasn't in the timeframe the article talks about. As far as I can recall, there is strong evidence that once the ice ages ended migration into North America ceased, which was much longer ago than the article is suggesting.
Well migration != migration for this purpose. It's enough for few or even single individuals to migrate (and "infect" other populations with their ancestry), not for whole populations to relocate in this case. This also moots the point about adaptation. The migrants just mix their DNA with the DNA of the resident population, no need to wait for evolutionary adaptation.
Of course the "walking 100 yards/day" metaphor is also wrong in this respect. It's rather one person in each generation finding a mate 100 miles away or something like that.
I can't judge the accuracy of all the study's assumptions. But they did take into account different geographical areas and different levels of migration between those areas. I think one very interesting point to consider is that only an extremely little amount of "interbreeding" is needed. Suppose there's just one single migrant coming to a sizeable (stable) population of 1.000.000 (~2^20) families, and producing at least some offsprint. Within 20 generations (on average) you'd expect him to be related to each and every newborn in that population. That's no more than 500 years for a single migrant to "infect" the entirety of even a large population, no matter how isolated it is. Even if three or four distinct "hops" are needed to "infect" the entire globe, that's very likely to happen over the course of 2000 years.
BTW, contrary to the slashdot summary, the article gives 5000 B.C., not 500 B.C. as the most conservative estimate, saying 1 A.D. might still be realistic, though.
Prove it.
I suppose that's not exactly possible to do. However, on surface value, their methodology (extensive simulation testing different assumptions on migration) seems pretty sound to me.
> It's a silly article.
It's not. Of course I don't know all the details of the study, but the article clearly explains it was a lot smarter than you assume. Some relevant fragments:
It's nothing more than exponential growth combined with the facts of life. By the 15th century you've got a million ancestors. By the 13th you've got a billion. Sometime around the 9th century just 40 generations ago the number tops a trillion.
But wait. How could anybody much less everybody alive today have had a trillion ancestors living during the 9th century?
The answer is, they didn't. Imagine there was a man living 1,200 years ago whose daughter was your mother's 36th great-grandmother, and whose son was your father's 36th great-grandfather. That would put him on two branches on your family tree, one on your mother's side and one on your father's.
[...]
The researchers knew they would have to account for geography to get a better picture of how the family tree converges as it reaches deeper into the past. They decided to build a massive computer simulation that would essentially re-enact the history of humanity as people were born, moved from one place to another, reproduced and died.
[...]
Allowing very little migration, Rohde's simulation produced a date of about 5,000 B.C. for humanity's most recent common ancestor. Assuming a higher, but still realistic, migration rate produced a shockingly recent date of around 1 A.D.
[...]
Migration is the key. When a people have offspring far from their birthplaces, they essentially introduce their entire family lines into their adopted populations, giving their immediate offspring and all who come after them a set of ancestors from far away.
Lot's of additional interesting tid-bits in that article. Worth a read IMO.
Not only that it's little compared to the running costs. I wonder how much of the energy required for the manufacturing is actually used for this one step. Let's do some calculations:
Heat capacity of Si at 25 C: 19.789 J/(mol*K)
Too lazy to look up the heat capacity at other temperatures right now, so let's estimate it to be twice that much at 1000 C.
Mass of Si: 28g/mol
So that's up to 1.4 J/(g*K).
Heating by 1000 K is an estimated 1400 J/g (max).
How much does you average CPU die weigh? 1g? 2g? Let's assume 10 grams to be on the safe side:
Energy needed per CPU in this manufacturing step: 14 kJ = 3.8 Wh.
I'll say, I'm not impressed. Sure, every little helps, but it's certainly not enough to get all excited over how "green" this new technology is. Of course, if it acutally allows to create circuits on new materials, then it's interesting news, indeed - but for an entirely different reason.
If you're asking that way, then yes, I think the one best reason to protect the environment (and I do have a long record of environmental activism) is that exploiting nature without limits will - typically only in the mid and long term - harm other human beings, ourselves, and mankind as a whole. I don't personally feel nature has a value "of it's own", although that attitude is certainly generally benefical.
But actually that's not the discussion I meant to initiate at all. Rather my reasoning goes something like this: Given that the effect occured in presence of mere pictures of eyes (instead of real surveilance), I suspect what's causing the effect is likely rooted deep in the unconscious, and in fact probably in our genes. Our genetic code, however, has evolved (not only) over the last few ten thousands of years, and the last few hundred don't count much at all on an evolutionary scale (all that's culture, not evolution). So: Environmental concerns are most certainly not in our genes. There was simply no need for it on an evolutionary scale. Up until "fairly recently", it was entirely ok, resource wise, to exploit nature to the maximum possible. Social situations are an entirely different beast, and it's very, very likely, that we have much programmed into our genes with respect to social behavior (though I believe much less than evolutionary biologists tend to proclaim).
So when I wrote "some natural ressource which can simply be exploited" I wasn't thinking "oil field" or "rain forest" so much, but more along the lines of "that hazelnut tree over there". Just pick the nuts and enjoy, no need to worry about others.
Hope this clarifies my previous post.
I'm afraid, your interpretation "reminder of being watched" is probably right. However, let's not jump to conclusions too fast, and give the belief in the good in humanity another chance. The eyes may also act as a reminder of "the coffee fund is a social institution, not some natural ressource which can simply be exploited".
An interesting variation would be to test eye-pictures vs. neutral pictures vs. picture showing human beings that are not directly watching (i.e. just a prompt for a social situation, not for being watched). I'd think this last type of pictures will be less effective than the eye-pictures, but maybe still somewhat effective compared to the neutral pictures.
Suppose that consultant were to get 100 requests a week, and cannot meet them in any sort of a timely fashion without cutting into his work time
Let's set aside the question, whether this is likely at all, for a moment. But if the poor consultant really gets 100 requests a week, why doesn't he contract someone do to this for him? As someone who has "run their own business" that would seem like an obvious solution, no? In fact, should you come into this situation, I'll happily do the work for you, and I'll only charge $40/h to the people requesting the source code, too.
- your way of thinking would obligate him to become a pauper for the convenience of the GPL at the demand of people who recieved a gift from him!
You're overlooking an important point: If you are bound by the obligations of the GPL, it's because you're distributing somebody else's work, not (only) yours. Your way of thinking would mean to put whoever you received a gift from to handle the work resulting from you passing it on. In some cases this "upstream author" will have much better infrastructure for dealing with requests for source, but in some cases they might even have more trouble, or their time may be even more costly. Hence, it's entirely reasonable to say: "If you redistribute my work, then you will have to deal with the end user". Just what the GPL does.
Or use a BSD-style license and avoid the whole mess. ;-)
Which is entirely reasonable, if - and only if - it's your original work, and you are not bound to respect any other author's rights. However in this case - you wrote it entirely from scratch - it really does not matter, which licence you chose. Even if you distribute your own work under the GPL, you can in no way be bound to it's restrictions. You are the sole copyright holder in this case, and so you have all the rights. The only thing you do is to tell people who redistribute your software, that they a) may do so b) only under certain conditions. One of those conditions is to tell redistributors that they should deal with the consequences of redistributing themselves, and not rely on you to do all the associated work. So it's more family time for the overworked consultant, not less. Nice, isn't it?
If the intention had been to create a judical precendent for the GPL, he would have had to do better. As is, the case failed at a much too basic level. Basically the court told him, he was not in a position to sue, no less and not much more. The judge did not even have to consider the GPL itself, hence no chanceof creating a real precedent IMO. If at all, what's been ruled on, is that it's not per se illegal to give something away for free. Big deal.
We'll have to wait until somebody else dumb enough to try to disprove the GPL in court, and smart enough to actually get the formal basics right, shows up. Daniel Wallace wasn't the one.
What is better? 20 companies devoting billions of dollars to the creation of a cure in search of profits, or 2 devoting millions in search of altruism? I put my money on the 20 to come up with something faster. For those who feel like giving money away, whether they be companies, or individuals, they are more than welcome to do so when a cure has been discovered.
Of course your point is valid. Yet, the problem behind it is valid as well: Yes, there are uneccessary deaths due to pharma-companies need to sell medication way above production cost.
So, while saying "the pharma shouldn't be allowed to make profit" obviously isn't a solution, the dilemma does not go away just like that. Maybe what is really needed for global epidemic diseases like AIDS is to look beyond purely business "the market will make it happen" solutions. Maybe the problem should really be attacked on a global scale, such as e.g. the UN offering a (large) "bounty" to whoever is first to develop an effictive medication, but at the same time preventing such a medication to be patent protected. This would still be offering a capitalist incentive to do research, but place control where it really belongs: Mankind as a whole.
And no, I'm not saying such a system could realistically be implemented any time soon. Maybe (or rather very probably so) it's a way to naive approach to a complex problem, too. But then, let's discuss alternative solutions in earnest, rather than just assuming, the world we live in was the best ever possible.
Ok, well, on second read, the numbers I cited can't be true on that magnitude. And either today my google skills are weak, or it's not quite easy to find definite figures. Anyway, I'm fairly certain, that at least on short-distance flights (~500 kilometers) air traffic needs between 50% and 100% more than road traffic per passenger-kilometer and on average. For long-distance flights air traffic becomes somewhat more efficient, as a considerable portion of energy is used during take-off. Possibly for really long distances (>5000 kilometers), air traffic may even be more efficient *per person-kilometer* than car traffic.
Yet, while my previous numbers were wrong, they are right at least in one respect: Air-traffic is evil on the short distance, as it's completely inefficient there. Air-traffic is evil on the long distance for the total amount of energy consumed on large distance journeys.
Sorry about the mistake
Comparing total energy consumption doesn't mean anything
True, at least on a certain level. I did, as the parent post did just that.
Compare energy use per pasenger and compare airplanes to car traffic and i'd imagine it'd look quite different
Yes, road passenger traffic is 40 tonnes of oil equivalent per 1 billion passenger kilometers. For air passenger traffic it's 1456 tonnes per billion passenger kilometers. I'm not sure, whether that's the direction you expected. (2003 prov; http://www.dti.gov.uk/energy/inform/energy_consump tion/table2_5.xls)
Planes also give off less pollution per passenger than most cars
To a certain extent planes give of different types of pollution than cars, so for some select emissions your statement may even be true. In general this is dead wrong. Planes give off much more pollution than cars, even per passenger.
Don't know, whether you have any specific emissions in mind, but I'd call this statement plain wrong. Currently total airflight energy use is about a quarter of total car traffic energy use (but admittedly airflight is growing at an alarming rate). Airplanes produce more emissions per distance, and also some particularily nasty types of pollution (water vapor in high altitudes, for instance, is a greenhouse factor), but it's not anywhere near surpassing car traffic in total, yet. (energy consumption in the UK. See page 14)
On standy: Yes, in many cases it makes life easier. However there is no wrong at all in 1) informing people that standby power usage is non-zero. Note that in some cases of bad design it's even quite considerable. Some inkjet printers use 15 Watts in standby - what for? 2) Pressure manufactures to make full-power-off reasonably easy.
Yes, there are areas other than standby, where (greater) amounts of energy can be saved. But also in many, many, many cases, summing up to hundreds or even thousands of megawatts, standby is just plain useless. Standby for a TV - ok, nice feature to have, if you like. Standby for a PC / printer / CD-/DVD-player? Heck, I'm typically right in front of those, when I want to start using them. What do I need standby for? Provide me with the option, fine, but give me an easy opportunity to switch them off fully, if only to reduce the risk of fire, or the damage done if lightning strikes nearby.