My ancestor Pharaoh Narmes again

I began this series of posts saying that I had discovered that there was an 80% chance that I was descended from Narmes, the first pharaoh of a united Egypt. As subsequent posts have indicated, I arrived at this, not by any detailed investigative work in tracking my lineage, but by depending upon the analysis of Douglas L. T. Rohde, Steve Olson, and Joseph T. Chang and published in the journal Nature.

After reading that paper, I became curious about who lived around the time of the identical ancestors and looked around to see if there was a named individual. I knew that writing was discovered around 5,000 years ago, so the time of the IA (identical ancestors) coincided roughly with the time that written records were starting to be kept. So there was a chance that there was a reliable contemporaneous written record of some person from the time of the IA. The chances were also great that the person whose life was recorded was likely to have been a big shot, a king or some such, whom people considered important enough to write about, on tombs and so forth.
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Sexual selection

In a previous post, I discussed the fact that although all of us have the identical set of ancestors who lived just 5,000 years ago, this does not mean that we have the same genes. The fact that we are different is due to the fact that if most of the mating occurs within a group, then this can result in certain features becoming emphasized. In extreme case, this initial isolated mating pattern can result in a new species being formed that cannot mate with other groups that it could have done in the past.

I had always thought that the two organisms belonged to different species if they were biologically different enough that they either could not produce offspring or, as in the case of mules produced by horses and donkeys, the offspring were infertile and thus not able to reproduce.

But I learned from Richard Dawkins’ book The Ancestor’s Tale (2004) that two things can be considered different species even if they are perfectly capable of producing fertile offspring. All that is required for them to be considered to be different species is that they are not found to mate in the wild for whatever reason.

Normally, this happens when there is some kind of barrier that separates two groups of the same species so that they cannot mate. “No longer able to interbreed, the two populations drift apart, or are pushed apart by natural selection in different evolutionary directions” (p. 339) and thus over time evolve into different species. But the separation can also occur due to sexual selection.

He gives a fascinating example of this on page 339. He describes experiments done with two species of cichlid fish. The two species live together in Lake Victoria in Africa and are very similar, except that one has a reddish color and the other bluish. Under normal conditions, females choose males of the same color. In other words, there was no hybridization between the two colors in the wild, thus meeting the requirements for being considered different species. But when experimenters lit the fish in artificial monochromatic light so that they all looked dirty brown, the females no longer discriminated among the males and mated equally with both kinds of males and the offspring of these hybrids were fully fertile.

He also describes ring speciation using the example of the herring gull and lesser black-backed gull (p. 302). In Britain, these two kinds of birds don’t hybridize even though they meet and even breed alongside one another in mixed colonies. Thus they are considered different species.

But he goes on to say:

If you follow the population of herring gulls westward to North America, then on around the world across Siberia and back to Europe again, you notice a curious fact. The ‘herring gulls’, as you move around the pole, gradually become less and less like herring gulls and more and more like lesser black-backed gulls, until it turns out that our Western European lesser black-backed gulls actually are the other end of a ring-shaped continuum which started with herring gulls. At every stage around the ring, the birds are sufficiently similar to their immediate neighbors in the ring to interbreed with them. Until, that is, the ends of the continuum are reached, and the ring bites itself in the tail. The herring gull and the lesser black-backed gull in Europe never interbreed, although they are linked by a continuous series of interbreeding colleagues all the way around the other side of the world.

Dawkins gives a similar example of this kind of ring speciation with salamanders in the Central Valley of California.

Why is this interesting? Because it addresses a point that sometimes comes up with skeptics of evolution. They try and argue that there is a contradiction if we had evolved from an ancestor species that was so different from us that we could not interbreed with that species. Surely, the argument goes, doesn’t speciation imply that if species A evolves into species B, then must there be a time when the child is of species B while the parent is of species A. And isn’t that a ridiculous notion?

The herring gulls and salamanders are the counterexamples in space (which we can directly see now) of the counterargument in time (which we can only infer). What it says is that as descendants are produced, they form a continuum in time. Each generation, while differing slightly, can interbreed with its previous generation, but over a long enough period of time, the two end points of the time continuum need not be able to interbreed.

Thus it is possible for an organism to be intermediate between two species.

Coming back to the question of why we look so different if we all shared common ancestors so recently, it is likely that the kind of selectivity practiced by the cichlid fish has resulted in certain features being shared by groups that interbreed within a restricted domain bounded by distance and geography and culture, although the process has not become so extreme that we have formed into distinct species.

I apologize for boring those readers who had had a much more extensive biology education than I have because all these things which I have been writing about recently on evolution must be well known to them. But I find all this perfectly fascinating and novel.

POST SCRIPT: Amy Goodman in Cleveland

Award-winning journalist Amy Goodman, host of the daily, grassroots, global, radio/TV news hour Democracy Now!, is on a national speaking tour to mark DN!’s 10th anniversary and launch her second book with journalist David Goodman, Static: Government Liars, Media Cheerleaders, and the People Who Fight Back.

WHEN: Saturday, October 14th, 7:00-8:30 PM
WHERE: Student Center,
John Carroll University,
20700 N. Park Blvd (University Heights), Cleveland, OH
DESCRIPTION: Amy Goodman speaks at a free event at the Student Center. Book signing to follow. Members of Iraq Veterans Against the War will give a brief presentation before the talk, as part of their collaboration with the Uprise Tour.
TICKETS: Free
MORE INFO: See here for directions.

Why we look different despite having identical ancestors

In the previous post in this series, I reported on a paper by Douglas L. T. Rohde, Steve Olson, and Joseph T. Chang and published in the journal Nature that said that if we go back about 5,000 years, the ancestors of everyone on Earth today are exactly the same. This date is called the IA point, where IA stands for ‘identical ancestors’.

One question that will immediately arise in people’s minds is that if all our identical ancestors lived so recently, how is it that we look so different? If you take four people from China, Sri Lanka, Sweden, and Malawi, they are usually fairly easily distinguishable based on physical appearance alone, using features such as skin color, hair, facial features, etc. How could this happen if they all had identical ancestors as recently as 5,000 years ago?

The answer lies in the fact that while it is true that we all share the same ancestors, it does not mean that we all received that same genetic information from that common ancestral pool.

It is true that each of us gets exactly half our genes from our fathers and half from our mothers. But when we pass on our genes to our children, while each child gets exactly half from each parent, that does not imply that they get exactly one quarter from each grandparent. What is true is that on average each child gets one quarter of the genes from each grandparent.

The reason for this is because when a sperm or egg is formed, the genetic information (say in the egg formed in the mother) that goes into it undergoes a process of recombination in which the genes the mother obtained from her parents get mixed up before the transfer into the egg. It is thus theoretically possible, though unlikely, that a child will have zero genetic information from one of her four grandparents.

Furthermore, as we go down to the next generation, the average genetic information received by a child is now just one-eighth from any given great-grandparent. After many generations, even the average contribution of someone to each descendant approaches zero and it is not hard to imagine that some ancestors will have descendants who inherited none of their genetic information. In fact, as Rohde, Olson, and Chang say, “because DNA is inherited in relatively large segments from ancestors, an individual will receive little or no actual genetic inheritance from the vast majority of the ancestors living at the IA point.”

Furthermore, “In generations sufficiently far removed from the present, some ancestors appear much more often than do others on any current individual’s family tree, and can therefore be expected to contribute proportionately more to his or her genetic inheritance. For example, a present-day Norwegian generally owes the majority of his or her ancestry to people living in northern Europe at the IA point, and a very small portion to people living throughout the rest of the world.”

So even though we all have the same set of ancestors, the amount of genetic information received from any one ancestor will vary wildly from person to person.

As long as populations remained largely isolated, they could thus evolve different physical characteristics, although even a tiny amount of migration between populations is enough to create the early common dates of the MRCA (most recent common ancestor) and IA.

There are some factors that could shift those dates back further.

If a group of humans were completely isolated, then no mixing could occur between that group and others, and the MRCA would have to have lived before the start of the isolation. A more recent MRCA would not arise until the groups were once again well integrated. In the case of Tasmania, which may have been completely isolated from mainland Australia between the flooding of the Bass Strait, 9,000–12,000 years ago, and the European colonization of the island, starting in 1803, the IA date for all living humans must fall before the start of isolation. However, the MRCA date would be unaffected, because today there are no remaining native Tasmanians without some European or mainland Australian ancestry.

No large group is known to have maintained complete reproductive isolation for extended periods.

It seems to me that these results arguing for the fact that our most recent common ancestor lived about 2,000 years ago and that we all have the same common ancestors who lived just 5,000 years ago are pretty robust.

This has profound implications for origins myths and tribalism. Some people like to have a sense of racial pride by thinking that they represent ‘pure’ races. This research argues that this view is rubbish. None of us are ‘pure’. We are all cousins, and fairly close ones at that.

The Supreme Court in the cross hairs

Some people now look to the US Supreme Court to overturn the torture-approving legislation passed last week by the Congress. Some members felt that it was unconstitutional but voted for it anyway, perhaps fearing that they would be charged with being ‘soft on terrorism.’

Depending on any single agency to defend fundamental rights on our behalf is a dangerous strategy because those agencies are susceptible to pressure.

Even though the present Supreme Court is already very sympathetic to the idea of giving the administration all the power it wants even when it is skating very close to the constitutional edge, the present administration is taking no chances that the courts will derail its efforts to do what it wants. We already see the administration’s efforts to intimidate the court so that it will go along with the administration’s wishes or, in the event that it does reject this legislation as unconstitutional, laying the groundwork to ignore the decision of the court.

Attorney General Alberto Gonzales already fired the opening salvo last week, by implying that if the courts overrule this legislation, they are imposing their personal views and should expect harsh criticism.

Attorney General Alberto Gonzales, who is defending President Bush’s anti-terrorism tactics in multiple court battles, said Friday that federal judges should not substitute their personal views for the president’s judgments in wartime.

He said the Constitution makes the president commander in chief and the Supreme Court has long recognized the president’s pre-eminent role in foreign affairs. “The Constitution, by contrast, provides the courts with relatively few tools to superintend military and foreign policy decisions, especially during wartime,” the attorney general told a conference on the judiciary at Georgetown University Law Center.

“Judges must resist the temptation to supplement those tools based on their own personal views about the wisdom of the policies under review,” Gonzales said.

And he said the independence of federal judges, who are appointed for life, “has never meant, and should never mean, that judges or their decisions should be immune” from public criticism.

“Respectfully, when courts issue decisions that overturn long-standing traditions or policies without proper support in text or precedent, they cannot — and should not — be shielded from criticism,” Gonzales said. “A proper sense of judicial humility requires judges to keep in mind the institutional limitations of the judiciary and the duties expressly assigned by the Constitution to the more politically accountable branches.”

Although this warning to the justices was quite blunt, Newt Gingrich, former speaker and supposed seeker for the Republican nomination for the presidency in 2008, was even blunter. He argued that the government has the right to simply ignore the verdict of the court.

Supreme Court decisions that are “so clearly at variance with the national will” should be overridden by the other branches of government, former House Speaker Newt Gingrich says.

“What I reject, out of hand, is the idea that by five to four, judges can rewrite the Constitution, but it takes two-thirds of the House, two-thirds of the Senate and three-fourths of the states to equal five judges,” Gingrich said during a Georgetown University Law Center conference on the judiciary.

It takes approval by two-thirds of Congress and three-fourths of the 50 states to adopt an amendment to the Constitution, the government’s bedrock document.

Gingrich, a Republican who represented a district in Georgia, noted that overwhelming majorities in Congress had reaffirmed the Pledge of Allegiance, and most of the public believes in its right to recite it.

As such, he said, “It would be a violation of the social compact of this country for the Supreme Court to decide otherwise and would lead, I hope, the two other branches to correct the court.”

This notion that someone can somehow divine the “will of the people” is always the one that is used by demagogues to ride roughshod over the institutional checks and balances that have been painstaking built up over the years. The constitution does not recognize the vague “social compacts” that Gingrich refers to. In fact, constitutions are deliberately designed to prevent the temporary passions that can engulf a people at certain times from creating lasting damage. In times of great stress, it may well be the “will of the people” to round up suspects and shoot them without trial, just like they used to summarily lynch black people. The whole point of the rule of law and constitutional protections is to restrain those who would act in the heat of the moment.

People like Gingrich and other enablers of authoritarian regimes like the one currently controlling the White House are always eager to dismantle these constitutional protections because they hinder their ambitions to achieve greater power and control over their people.

I am constantly amazed at how this government is doing the same thing that the Sri Lankan president did following his election in 1977. It is almost as if there is some kind of secret listserv that all authoritarian leaders can sign on to so that they know what they need to do to circumvent constitutional protections and grab more power. That Sri Lankan president too constantly asserted that the “will of the people” supported whatever he wanted to do and proceeded to systematically rewrite the constitution to give him more power. He too set about intimidating the Supreme Court by issuing harsh criticisms of their decisions and organizing demonstrations in front of the judge’s homes.

John Dean, who was White House counsel to President Nixon and thus witnessed the authoritarian mindset close up, says in an interview in the October 2006 issue of The Progressive magazine that this administration, especially Dick Cheney, has been determined to expand presidential powers. He says he “can’t find in history any other Presidency that has made it a matter of policy to expand Presidential powers.” He adds, “To me the fact that a Vice President can go to Capitol Hill and lobby for torture is just unbelievable. Just unbelievable! I can’t even get there mentally.”

The interview ends with him saying “I fear for the [democratic] system. And I fear for our liberties.”

In order to understand the dynamics of what is going on currently we have to develop a new framework with which to analyze events.

First of all we have to realize that the real enemy of an authoritarian government is not some external threat but the very people it is supposed to be governing. Their real goal is to cow, intimidate, and otherwise subdue their own population so that they will not resist the actions of the government.

In the current case, we are repeatedly told that the enemy the country is facing is terrorism and these kinds of torture legislation are the weapons it needs to fight it. But the actions of this regime are easier to understand if we realize that we, the people, are the real enemy of the administration, and the fear of terrorism is the weapon used to control us.

In order to resist the steady evisceration of basic liberties and the constitution, we cannot depend on our elected representatives or the judiciary to take the lead and fight for those rights. They are too craven to lead. They will only follow. The only way to safeguard civil liberties and constitutional freedoms is by everyone loudly and vocally valuing them, protecting them, and using them. The words of Judge Learned Hand are always worth remembering and repeating:

Liberty lies in the hearts of men and women; when it dies there, no constitution, no law, no court can even do much to help it. While it lies there it needs no constitution, no law, no court to save it.

If Judge Learned hand were alive today, I wonder what his verdict would be.

It is quite amazing to me that the Bill of Rights, that shining jewel in the US constitution that is a landmark in the conceptualizing of the fundamental protections that any civilized society should afford its people, is now seen as some sort of quaint anachronism, something that can be dispensed with at the whim of an authoritarian government that claims that it, and it alone, knows what the “will of the people” is.

POST SCRIPT: Exposing the posturers

The Daily Show highlights the hypocrisy and posturing of Senators John “Straight Talk Express” McCain, Lindsey Graham, Arlen Specter, and John Warner on the detainee bill.

Constitutionality of torture

Republican senators Arlen Specter and John McCain and Lindsey Graham are media favorites who get a lot of positive attention for seeming to stand up for the right thing even though they almost invariably capitulate to the White House. (McCain in particular has this totally undeserved reputation as a ‘maverick’ and ‘straight talker’ and ‘moderate’ when in fact all he does is talk and does not back it up with action that would make such a reputation truly deserved. To me he seems like any other Bush-kowtowing hardliner.)
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No one is now safe from arbitrary imprisonment and torture

In yesterday’s post I spoke about the qualitative change that has occurred in this country as a result of the passage of the legislation last week that took away almost all the rights on which a truly free society is built.

Some people may be consoling themselves that these drastic actions will be only taken against “other” people, non-US citizens, and that they themselves are safe. But Bruce Ackerman, a professor of law and political science at Yale and author of Before the Next Attack: Preserving Civil Liberties in an Age of Terrorism, writing in the September 28, 2006 issue of the Los Angeles Times warns us not to be so complacent:

Buried in the complex Senate compromise on detainee treatment is a real shocker, reaching far beyond the legal struggles about foreign terrorist suspects in the Guantanamo Bay fortress. The compromise legislation, which is racing toward the White House, authorizes the president to seize American citizens as enemy combatants, even if they have never left the United States. And once thrown into military prison, they cannot expect a trial by their peers or any other of the normal protections of the Bill of Rights.

This dangerous compromise not only authorizes the president to seize and hold terrorists who have fought against our troops “during an armed conflict,” it also allows him to seize anybody who has “purposefully and materially supported hostilities against the United States.” This grants the president enormous power over citizens and legal residents. They can be designated as enemy combatants if they have contributed money to a Middle Eastern charity, and they can be held indefinitely in a military prison.

Not to worry, say the bill’s defenders. The president can’t detain somebody who has given money innocently, just those who contributed to terrorists on purpose.

But other provisions of the bill call even this limitation into question. What is worse, if the federal courts support the president’s initial detention decision, ordinary Americans would be required to defend themselves before a military tribunal without the constitutional guarantees provided in criminal trials.

Legal residents who aren’t citizens are treated even more harshly. The bill entirely cuts off their access to federal habeas corpus, leaving them at the mercy of the president’s suspicions.

We are not dealing with hypothetical abuses. The president has already subjected a citizen to military confinement. Consider the case of Jose Padilla. A few months after 9/11, he was seized by the Bush administration as an “enemy combatant” upon his arrival at Chicago’s O’Hare International Airport. He was wearing civilian clothes and had no weapons. Despite his American citizenship, he was held for more than three years in a military brig, without any chance to challenge his detention before a military or civilian tribunal. After a federal appellate court upheld the president’s extraordinary action, the Supreme Court refused to hear the case, handing the administration’s lawyers a terrible precedent.

The new bill, if passed, would further entrench presidential power. At the very least, it would encourage the Supreme Court to draw an invidious distinction between citizens and legal residents. There are tens of millions of legal immigrants living among us, and the bill encourages the justices to uphold mass detentions without the semblance of judicial review.

This act provides a dramatic gauge of how far has this nation’s concepts of justice have sunk since the times when the constitution was first drafted (leaving aside for the moment the problem that those noble early concepts of justice did not extend to black people). For example, Thomas Jefferson said in his first inaugural address: “Freedom of the person under the protection of the habeas corpus I deem [one of the] essential principles of our government.”

Jefferson had little sympathy for those who would suspend these basic rights at the first sign of any trouble saying in a letter to James Madison that he felt that habeas corpus should be preserved even if there is an insurrection or rebellion within the country, which is a far, far, greater threat than anything faced today in the so-called war on terror. He pointed out the history of such suspensions which indicated that it was usually done for the consolidation of power by an authoritarian government rather than for genuine concerns about security, saying:

Why suspend the habeas corpus in insurrections and rebellions? The parties who may be arrested may be charged instantly with a well defined crime; of course, the judge will remand them. If the public safety requires that the government should have a man imprisoned on less probable testimony in those than in other emergencies, let him be taken and tried, retaken and retried, while the necessity continues, only giving him redress against the government for damages. Examine the history of England. See how few of the cases of the suspension of the habeas corpus law have been worthy of that suspension. They have been either real treasons, wherein the parties might as well have been charged at once, or sham plots, where it was shameful they should ever have been suspected. Yet for the few cases wherein the suspension of the habeas corpus has done real good, that operation is now become habitual and the minds of the nation almost prepared to live under its constant suspension.

It is a sign of how debased the political discussion has become in this country that if Jefferson has spoken such words today, he would be reviled as a wimp and a mollycoddler of Islamojihadifascists (or whatever the current demonizing term being used to make people cower in fear), as ‘not supporting the president’ by ‘giving him the tools he needs to fight terrorists.’
POST SCRIPT: It could be worse, I suppose

Cartoonist Tom Tomorrow sums up the current state of affairs.

What happened to the ‘land of the free’?

Last Thursday saw the day when the US as a nation formally decided that it no longer accepted the basic human rights that have been the foundation of its civil society since the time it adopted the Bill of Rights. In particular, the nation went on record as declaring that habeas corpus was expendable and torture was acceptable. Of course, torture has been practiced in the past by individuals, even individuals acting on behalf of the government. But when those things were revealed most recently at Abu Ghraib and Guantanamo, we could at least try and argue that these were the abhorrent actions of a few ‘rogue elements’ and ‘bad apples’ and did not represent the ideals of the people as a whole.

But when the House of Representatives and the Senate last week passed the Military Commissions Act of 2006 allowing these things, and when the president signs these practices into law, then we can no longer use such excuses. These people were all elected to their offices and can claim that they represent the people of their regions. Hence by passing this act America, as a nation, has now formally gone on record as saying that the Bill of Rights, the Universal Declaration of Human Rights, and the Geneva Conventions are all expendable, subservient to whatever measures, however extreme, the president deems necessary to fight his ‘war on terror.’ The American people, through their elected representatives, are in effect giving the president the powers eagerly sought by dictators.

In this Washington Post news report from September 28, 2006 we can read a description of the legislation.

Included in the bill, passed by Republican majorities in the Senate yesterday and the House on Wednesday, are unique rules that bar terrorism suspects from challenging their detention or treatment through traditional habeas corpus petitions. They allow prosecutors, under certain conditions, to use evidence collected through hearsay or coercion to seek criminal convictions.

The bill rejects the right to a speedy trial and limits the traditional right to self-representation by requiring that defendants accept military defense attorneys. Panels of military officers need not reach unanimous agreement to win convictions, except in death penalty cases, and appeals must go through a second military panel before reaching a federal civilian court.

By writing into law for the first time the definition of an “unlawful enemy combatant,” the bill empowers the executive branch to detain indefinitely anyone it determines to have “purposefully and materially” supported anti-U.S. hostilities. Only foreign nationals among those detainees can be tried by the military commissions, as they are known, and sentenced to decades in jail or put to death.

At the same time, the bill immunizes U.S. officials from prosecution for cruel, inhumane or degrading treatment of detainees who the military and the CIA captured before the end of last year. It gives the president a dominant but not exclusive role in setting the rules for future interrogations of terrorism suspects.
. . .
Tom Malinowski, the Washington office director for Human Rights Watch, said Bush’s motivation is partly to protect his reputation by gaining congressional endorsement of controversial actions already taken. “He’s been accused of authorizing criminal torture in a way that has hurt America and could come back to haunt our troops. One of his purposes is to have Congress stand with him in the dock,” Malinowski said.
. . .
University of Texas constitutional law professor Sanford V. Levinson described the bill in an Internet posting as the mark of a “banana republic.” Yale Law School Dean Harold Koh said that “the image of Congress rushing to strip jurisdiction from the courts in response to a politically created emergency is really quite shocking, and it’s not clear that most of the members understand what they’ve done.”

The New York Times wrote a primer on the legislation in its editorial on September 28, 2006:

These are some of the bill’s biggest flaws:
Enemy Combatants: A dangerously broad definition of “illegal enemy combatant” in the bill could subject legal residents of the United States, as well as foreign citizens living in their own countries, to summary arrest and indefinite detention with no hope of appeal. The president could give the power to apply this label to anyone he wanted.

The Geneva Conventions: The bill would repudiate a half-century of international precedent by allowing Mr. Bush to decide on his own what abusive interrogation methods he considered permissible. And his decision could stay secret — there’s no requirement that this list be published.

Habeas Corpus: Detainees in U.S. military prisons would lose the basic right to challenge their imprisonment. These cases do not clog the courts, nor coddle terrorists. They simply give wrongly imprisoned people a chance to prove their innocence.

Judicial Review: The courts would have no power to review any aspect of this new system, except verdicts by military tribunals. The bill would limit appeals and bar legal actions based on the Geneva Conventions, directly or indirectly. All Mr. Bush would have to do to lock anyone up forever is to declare him an illegal combatant and not have a trial.

Coerced Evidence: Coerced evidence would be permissible if a judge considered it reliable — already a contradiction in terms — and relevant. Coercion is defined in a way that exempts anything done before the passage of the 2005 Detainee Treatment Act, and anything else Mr. Bush chooses.

Secret Evidence: American standards of justice prohibit evidence and testimony that is kept secret from the defendant, whether the accused is a corporate executive or a mass murderer. But the bill as redrafted by Mr. Cheney seems to weaken protections against such evidence.

Offenses: The definition of torture is unacceptably narrow, a virtual reprise of the deeply cynical memos the administration produced after 9/11. Rape and sexual assault are defined in a retrograde way that covers only forced or coerced activity, and not other forms of nonconsensual sex. The bill would effectively eliminate the idea of rape as torture.

There is not enough time to fix these bills, especially since the few Republicans who call themselves moderates have been whipped into line, and the Democratic leadership in the Senate seems to have misplaced its spine. If there was ever a moment for a filibuster, this was it.

The craven Democrats not only did not filibuster this bill in the Senate, some of them even voted in favor of it. In the House, ‘liberals’ such as Sherrod Brown (now running for the Ohio Senate seat) and Ted Strickland (now running for Ohio governor) also voted in favor of it, thus reinforcing my long-held view that traditional political labels have ceased to have meaning in terms of policy positions that are favored by the pro-war/pro-business party.

(Incidentally, Strickland is also an ordained minister in my old church (Methodist) which suggests that for some ‘liberal’ clergy, torture is just fine with their idea of what Jesus stood for. The minister in the Methodist Church I grew up in, Rev. Arnold Cooper, passed away last month. He was a wonderful, humane man who had a great influence on me. He would have been revolted at the thought of a fellow clergyman in his church even thinking of condoning torture.)

[UPDATE: I stand corrected by Tom Maley in the comments. He is right that Strickland did not vote for or against the bill, but was absent. I have been trying to see if Strickland has made any statement either way about the bill but have not been able to find any mention of it, not even on his blog. So while his silence on such a major issue is disturbing, Strickland deserves my apologies for not verifying the facts of his vote. I should not have been depending on second-hand information.]

What this action has done is to make us all accomplices in these terrible things, while providing amnesty for those administration officials who actually carry them out. History is not going to judge us kindly.

POST SCRIPT: The Iraq war, lie by lie

The lies of this administration regarding the Iraq war are so numerous that one can be excused for feeling overwhelmed trying to keep track of them. Mother Jones has provided a great indexed timeline here. It is a terrific resource for anyone who cares about unearthing the truth that is being buried under high drifts of official duplicity and uncritical media reporting.

Realistic calculation of the date of our most recent common ancestor

In the previous posting, I discussed the calculation of Joseph T. Chang in which he showed that the most recent common ancestor (MRCA) of all the people living today lived around 1100 CE, while around 400 CE everyone who lived then was either the ancestor of all of us or none of us. The date when this occurs is called the IA (identical ancestor) date.

Chang got these results assuming that the population is constant over time at some value N, that the generations (with each generation lasting 30 years) are discrete and non-overlapping (i.e. mating took place only between males and females of the same generation), and that mating was random (i.e., there was equal probability of any one male in a generation to breed with any female of that same generation.)

What happens to these dates if you relax these unrealistic assumptions? One practical difficulty of going to more realistic models is that exact mathematical calculations become impossible and one has to resort to computer simulations. This was done by Douglas L. T. Rohde, Steve Olson, and Joseph T. Chang and their results were published in the journal Nature (vol. 431, September 30, 2004, pages 562-566).

As a first improvement, they divided the world into ten population centers (or ‘nodes’): one each in North America, South America, Greenland, Australia, the Pacific Islands, and the Indonesian archipelago, and two nodes in Africa and in Asia. Within each subpopulation, they assumed random mating, but allowed for neighboring populations to exchange just one pair of migrants per generation. Their computer models found that the best way to accommodate varying populations was to take a fixed value N equal to the population at the time of the MRCA. They assumed N to be 250 million, which was approximately the global population in the year I CE.

Using this more realistic model, and a generation span of 30 years, they obtained the MRCA date as 300 BC and the IA date as about 3,000 BCE, both still surprisingly recent.

They then constructed an even more sophisticated and realistic model. They broke up the inhabited area into three levels of substructure: continents, countries, and towns. (These were not real places, of course, just models, but they used our knowledge of geography and migrations routes that existed before 1,500 CE to create their models.)

The model allowed for each person to have a single opportunity to migrate from his or her town of birth. Within a country, they could migrate to any other town. If the migrants went to another country, the probability of that occurring decreased with the distance to the new country. To go to another continent required them to go through certain ports, and so on. The model also incorporated our knowledge of the size of ports and when they opened up.

Generations could also overlap in this model and the birth rate of each continent was adjusted to match historical estimates.

After making all these sophisticated adjustments to make their model more realistic, they arrived at what they felt was a reasonable estimate for the MRCA and IA dates. It turns out that the MRCA lived around 55 CE and the IA date is about 2,000 BCE. They also found that our most recent common ancestor probably lived in eastern Asia, not Africa as had been commonly supposed.

So despite going to considerable lengths to simulate a realistic pattern of population growth, mating, and migration, the dates arrived at for the MRCA and the IA are still surprisingly recent.

(If the authors of the paper made their parameters very conservative, they pushed the date for the MRCA only as far back to 1,415 BCE and the IA date to 5,353 BCE.)

A little reflection should persuade anyone that this result that our most recent common ancestor lived as late as 55 CE and in just 2,000 BCE we had identical ancestors has profound implications for the way we view ourselves and our relationship with others. The authors capture the wonder of it all when they end their paper with the following comment:

[O]ur findings suggest a remarkable proposition: no matter the languages we speak or the colour of our skin, we share ancestors who planted rice on the banks of the Yangtze, who first domesticated horses on the steppes of the Ukraine, who hunted giant sloths in the forests of North and South America, and who laboured to build the Great Pyramid of Khufu.

I find this amazing and remarkably encouraging. It should be more widely known. If more people realized how close we are to each other, perhaps we would stop killing one another and treat each other like the fairly close relatives we truly are.

The most recent common ancestor of all humans living today

In order to find the date of the most recent common ancestor (MRCA) of all the people living today, Chang started out by constructing a simple mathematical model of population mixing. (See here for some background to this post.)

He assumed that the population is constant over time at some value N. He assumed that the generations are discrete and non-overlapping (i.e. mating took place only between males and females of the same generation). He also assumed that mating was random. In words, that there was equal probability of any one male in a generation to breed with any female of that same generation.
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Some surprising facts about ancestors

In 1999, Joseph T. Chang published a very interesting paper in the journal Advances in Applied Probability (vol. 31, pages 1002-1026) titled Recent Common Ancestors of all Present-Day Individuals. To understand the paper, it helps to reflect a little on the mathematics of genealogy.

One rock-solid fact of ancestry is that every person has two, and only two, biological parents. They in turn each have two parents so going back two generations gives a person four ancestors. If you go back three generations, you have eight ancestors and so on. Each generation that you go back doubles the number of ancestors in the previous generation.

We all know that this kind of geometric progression results in one reaching very large numbers very soon and by thirty generations, the number of ancestors one has acquired has ballooned to over one billion. In forty generations, we have over one trillion ancestors.

Conservatively allowing for each generation to span 30 years (which is a little large), going back thirty generations takes us back to about 1100 CE where the population was only about 300 million, and forty generations takes us back to 800 CE where the population was less than 200 million. (If we take each generation as averaging 25 years, 30 generations takes us back to 1250 CE when the population was 350 million and in forty generations we reach 1000 CE where the population was 200 million.)

Having more ancestors that the total population leads to the clear conclusion (which is not that surprising once one thinks about it) that all our ancestors cannot have been distinct individuals but were shared. In other words, my great-great-great-grandfather on my father’s side had to be the same person as my great-great-grandfather on my mother’s side, or something like that.

But the interesting point is that each one of us has over a trillion ancestors in just forty generations, which must mean that you, the reader, and I must have some shared ancestors, unless the huge population of your ancestors were entirely isolated from the huge population of my ancestors, with no mixing at all between them. Given the large numbers of ancestors involved, this kind of isolation seems highly unlikely unless there was some major geographical barrier separating the populations. We know that this is not the case, since by 1000 CE, people were able to travel pretty much all over the inhabited world, and all you need is just one person from my group of ancestors mating with one person from your group of ancestors to break the isolation, because then the ancestors of that pair are shared by both of us.

So if you and I (as just two people) share common ancestors, then we can see that if we go back far enough in time, all of us living on the world today should share at least some common ancestors. (See this post for a more rigorous argument for this.) One question that Chang was investigating was that of finding out, from among all the common ancestors, when the most recent common ancestor (MRCA) of all the people living in the world today lived.

The concept of the MRCA is interesting. My siblings and I share all our ancestors so the MRCA is not meaningful. The MRCA of my cousins and I (say) are the one set of grandparents that we have in common. As my current relatives get more distant, the MRCA goes back in time but it is not hard to see that an MRCA must exist for those who are commonly referred to as ‘blood’ relatives.

As another example, for those who take the Bible literally, definite common ancestors would be Noah and his wife. Since everyone except the two of them and their sons and their sons’ wives were killed by god in the flood, all the current inhabitants of the world should have Noah and his wife as common ancestors. But they may not be the MRCA because their sons’ descendants may also have intermarried, creating a more recent MRCA.

For those of us who accept evolution, it is not hard to get our minds around the concept of all of us having an MRCA, and the fact that we must have a shared ancestor in an earlier species has a pretty rigorous proof and is fairly easily accepted. What people thought was that this person probably existed around the time of our ancestor Homo erectus, perhaps a million years ago.

But when analysis was done on the mitochondrial DNA, and its mutation rate was used to triangulate back to the time when all the current mitochondrial DNA converged on a single individual, people were surprised that the calculations revealed that the MRCA deduced from this analysis, (nicknamed Mitochondrial Eve) lived much more recently, only about 140,000 years ago, probably in Africa. All present-day mitochondrial DNA is descended from this single individual. A similar analysis can be done for the Y chromosome to trace back to ‘Y-chromosome Adam’, and that person lived about 60,000 years ago (Richard Dawkins, The Ancestor’s Tale (2004), pages 52-55).

But as Dawkins cautions (page 54):

[I]t is important to understand that Eve and Adam are only two out of a multitude of MRCAs that we could reach if we traced our way back through different lines. They are the special-case common ancestors that we reach if we travel up the family tree from mother to mother to mother, or father to father to father respectively. But there are many, many other ways of going up the family tree: mother to father to father to mother, mother to mother to father to father, and so forth. Each of these pathways will have a different MRCA.

Our normal concept of genealogy traces back through both sexes and thus the web of ancestral pathways becomes increases tangled and complex as you go back in time. As a result there is a greater chance of my ancestral pathways intersecting with the ancestral pathways of other people. It is thus reasonable to suppose that if we look at all these pathways, we will find a more recent MRCA than Mitochondrial Eve or Y-chromosome Adam. But this kind of calculation using mutation rates is not easy to do for things other than sex-specific chromosomes like mitochondrial DNA.

In order to try and fix the date of existence of the MRCA of everyone living today using the lines through both sexes, Chang used the tools of mathematics and statistics rather than genealogical charts or DNA mutations. And he found something very surprising, to be discussed in the next posting.

POST SCRIPT: If you live in fear, the terrorists have won

Tom Tomorrow points out the absurdity of people terrorizing themselves.