Blue-eyed Humans Have A Single, Common Ancestor

As explained in an article in ScienceDaily for January 31, 2008,

New research shows that people with blue eyes have a single, common ancestor. A team at the University of Copenhagen have tracked down a genetic mutation which took place 6-10,000 years ago and is the cause of the eye colour of all blue-eyed humans alive on the planet today.

The World Science article is here.

Race - the Power of an Illusion

Thoughts on race by Professor Joseph Graves, Jr.

Parallel: A Common Ancestry

This is a parallel between science and religion that I hadn't thought of until I read a report about new genetic information disagreeing with the prevailing scientific view that races don't actually exist and are just social creations. That article triggered my mind to think about the Tower of Babel and the changing of the languages of the people.

First I'd like to talk about this issue from the religious viewpoint. Then I will talk about it from the scientific view.

Prior to the time of the Tower of Babel, all of the people spoke a common language and probably had common cultural customs. When the Lord changed their languages, he scattered them throughout "all the earth". I am not writing about the question whether that was all the planet as we think of it today or was just all of their known world, but people who have strong views about that question are invited to reply to this post and express their view. From the Biblical viewpoint, this was the beginning of ethnic languages and customs. Thus, we see that the people did have a common ancestry, and they did have common customs until they were were scattered.

Concerning the genetics of these people, there were eight people who left the ark and repopulated the earth. The three sons of Noah would have had genes in common with Noah but not completely identical to his genome. The three wives of Noah's sons would each have had their own genetic pool. Thus, we see that the grand children of Noah, and later generations, would have had some genes in common with Noah but other genes different than him. In addition, during the time between the flood and the building of the Tower of Babel, mutations to the genes could have occurred. I don't know much about genetics, and I don't know the likelihood of mutations occurring in a period of a few hundred years to perhaps a thousand years. In summary, the people living at the time of the Tower of Babel probably would have had a commonality in their genes plus variances due to ancestry and mutations.

So much for the religious view. Now, let's look at the scientific view. In recent years, many scientists have thought that genetically all people were the same and that there was no genetic basis for having different races. This is not to say that everyone had exactly the same genes but that the differences were not the bases for different races. This view was the basis of my post on We are 99.9% the same.

Recent research, however, has shown that there are genetic differences between races. One reason for this is that different races have different ancestries and thus different gene-pools. However, scientists are divided as to the magnitude of the genetic differences in races. Some scientists think "There is considerable structural variation in the human genome [genetic code], most of which was not previously apparent". Scientists at the Howard Hughes Medical Institute reported that "at least 10 percent of genes in the human population can vary in the number of copies of DNA sequences they contain". Other scientists, though, say the genetic differences are small. Stephen W. Scherer of the Hospital for Sick Children in Toronto, Canada said, "Taking all types of DNA variation into consideration and looking at the entire 'content' of the genome, I would now say we are 99.7 - 99.8 percent identical". In summary, there seems to be a genetic basis for believing that races are real, but the differences between the races may be relatively small.

Both the religious view and the scientific view give a basis for believing that the peoples of the earth do have a common ancestry of some type but that differences in language, customs, and genetic information have changed over time. This all makes sense to me.

When I first started thinking about the religious view giving Noah as the "father" of all persons living on the earth, I began to wonder if he lived far enough back to be the common ancestor of everyone. Genetic genealogists refer to this common ancestor as the MRCA, the most recent common ancestor, and they estimate that a MRCA would have lived approximately 2,000 years to 5,000 years ago, as I documented in What is a Most Recent Common Ancestor (MRCA)?. From the religious view, Noah would thus be our MRCA. That time-frame fits in with an estimated date of the Tower of Babel being approximately 3500 BC, and the flood being a few hundred years or so before that.

To parallel a point I made at the beginning of this blog, I am not asserting that science has proved that Noah was our MRCA. I am not saying that science has proved that God did change the language of the people and scatter them on the earth. I am merely showing that there is an interesting parallel between the scientific view of a common ancestor and the Biblical story of Noah and of his descendants who built the Tower of Babel.

What is a Most Recent Common Ancestor (MRCA)?

After reading the post about the three scientists who created mathematical models of the MRCA of the human race, I became confused. It didn't make sense to me that a person living as recent as 3,000 years ago could be the only one who was an ancestor to the human race. There must have been many people living back then, and surely they had descendants who have survived to today. So, to get a better understanding, I turned to Wikipedia and read about MRCA.

The ancestry tree is not really a tree, but a directed, acyclic graph. One can place all living people at the bottom of the graph and ancestors above their descendants. As each generation of ancestor is added at the top of the graph, one of the many top-level ancestors will eventually become the MRCA from whom it is possible to trace a path of direct descendants all the way down to every living person at the bottom of the graph. (Wikipedia, MRCA of all living humans)

That is, the MRCA is the most recent ancestor of all the human race, while contemporaries of the MRCA either have no descendants alive today or have subsets of the human race alive today but not the whole human race.

Another article in Wikipedia said the MRCA is about 2,000 to 5,000 years ago, indicating the 3,000 figure obtained by the mathematical models is reasonable.

'Most Recent Common Ancestor' Of All Living Humans Surprisingly Recent

In an article dated September 30, 2004, Science Daily reported on models of human descent by a Yale University mathematician and two other scientists. According to the models, the direct ancestor of all humans alive today may have lived as recent as 3,000 years ago.

The current paper presents more realistic mathematical and computer models. It incorporates factors such as socially driven mating, physical barriers of geography and migration, and recorded historical events. Although such complexities make pure mathematical analysis difficult, it was possible to integrate them into an elaborate computer simulation model. The computer repeatedly simulated history under varying assumptions, tracking the lives, movements, and reproduction of all people who lived within the last 20,000 years.

The paper was first published in the Letters section of Nature magazine on September 30, 2004. A search of the Nature archives didn't show any comments about the letter from other scientists.

Studies Contradict View that Race Doesn’t Exist

The World Science web site reported that new research is showing that genetic differences do exist across the human genome.

Although it was reported as the largest study to find genetic differences between races, Risch’s study is not the first. Previous studies have found that Ashkenazi Jews are genetically more susceptible than average for Tay-Sachs disease, a fatal nervous system disorder, for instance. Black populations have been found to carry higher levels of a mutation that leads to sickle-cell anemia.

Risch’s study, however, is not only the largest study but also the first to find that these genetic differences are not isolated cases involving a handful of genes, but are spread throughout the genome

New Findings Undermine Basis of “Race Isn’t Real” Theory

The New World web site posted information, under a date of September 8, 2004, that new research is showing greater genetic differences in human beings than the popularly believed 99.9% figure would indicate.

“The 99.9 percent number is pure nonsense,” wrote Michael Wigler, of Cold Spring Harbor Laboratory, New York, in a recent email. “I will not say anything more about it.” However, he added, “it is true that humans are more like each other than many other species.”

Wigler is a co-author of one of the two studies, which is published in the July 23 advance online edition of the prestigious research journal Science. In it, the researchers wrote that they were surprised to find large-scale differences in human DNA. “There is considerable structural variation in the human genome [genetic code], most of which was not previously apparent,” they wrote.

However, scientists differ on the impact of the new research on the popular belief that humans are all the same.

We are 99.9% the Same

Many scientists have said for years that there are no basic differences between human beings. Race is just a "social construct". When the mapping of the human genome was completed in 2003, .the results of the mapping gave credence to the belief that we are all genetically the same.

Most studies of human genetic variation have focused on single nucleotide polymorphisms (SNPs), which are substitutions in individual bases along a chromosome. Most analyses estimate that SNPs occur on average somewhere between every 1 in 100 and 1 in 1,000 base pairs in the euchromatic human genome, although they do not occur at a uniform density. Thus follows the popular statement that "we are all, regardless of race, genetically 99.9% the same" -- Wikipedia, Human Genome

President Clinton used this common belief in a 2000 address in which he said, "All human beings, regardless of race, are more than 99.9 percent the same."

Mormon Belief: The Lord Changed the Language Of the People & Scattered Them

As Noah's descendants became numerous, many of them became wicked and conspired to build a large building that would reach unto Heaven. The Lord changed their language and scattered them upon the face of the earth.

And they said, Go to, let us build us a city and a tower, whose top may reach unto heaven; and let us make us a name, let we be scattered abroad upon the face of the whole earth.

And the Lord came down to see the city and the tower, which the children of men builded.

And the Lord said, Behold the people is one, and they have all one language; and this they begin to do and now nothing will be restrained from them, which they have imagined to do.

Go to, let us go down, and there confound their language, that they may not understand one another's speech.

So the Lord scattered them abroad from thence upon the face of all the earth: and they left off to build the city. (Genesis 11:4-8)

Mormon Belief: The Peoples of the Earth Came From Noah

After the flood had receded, Noah and his three sons and their families began to re-populate the earth.

And God blessed Noah and his sons, and said unto them, Be fruitful, and multiply, and replenish [fill] the earth. (Genesis 9:1)