Tag Archives: evolution

Gotcha:

We saw 12 Years a Slave last night. Powerful.

Funny thread

I was interested to learn that a currently fashionable notion of Christian fundamentalists holds that Adam, being a farmer, had to be from the vicinity of modern day Turkey. Adam was the first man by virtue of having genes which allowed him to be an agriculturist right from the git-go. So, the other older ‘out of Africa’ humans were actually not humans like Adam was a human because their more primitive genes only allowed them to be hunter/gatherers. Oh, and Adam being the first human and created by God, lived to be 930 years old too.

Was the world populated through incest or did God create others besides Adam and Eve? (via Bible.org)

While some understand the reference to Adam in Genesis to be a general reference to mankind as a whole or the creation of more than one couple, most conservative scholars reject such a view and understand the Genesis account to refer to the creation of a literal Adam and Eve as a single couple. This is further supported by the NT. For instance Paul understood the OT to refer to a literal Adam and Eve (see Rom. 5:14; 2 Cor. 11:3; 1 Tim. 2:12-13). He clearly understood the reference to Adam and Eve to the first man and woman.
As to incest, it was not considered a sin and was not prohibited for Adam and early man. If the race was to populate and fulfill the command of Gen. 1:28, there is little doubt that Adam’s sons and daughters had to have married their own sisters and brothers if the race was to populate the earth, but due to the purity of the race as evidenced also by the long length of life, there were no adverse effects as we see happening today. Gradually, as the effects of sin took its toll on the human race, marrying one’s own sister, etc., began to create hereditary problems.

Here is Ryrie’s comment on this issue from his book Basic Theology (1986 ed) which I would highly recommend.
Though by many inerrantists the question of where Cain got his wife would not be considered a problem at all, this question is often used by those who try to demonstrate that the Bible is unreliable in what it claims. How could it claim that Adam and Eve were the first human beings who had two sons, one of whom murdered the other, and yet who produced a large race of people? Clearly, the Bible does teach that Adam and Eve were the first created human beings. The Lord affirmed this in Matthew 19:3-9. The genealogy of Christ is traced back to Adam (Luke 3:38). Jude 14 identifies Enoch as the seventh from Adam. This could hardly mean the seventh from “mankind,” an interpretation that would be necessary if Adam were not an individual as some claim. Clearly, Cain murdered Abel and yet many people were born. Where did Cain get his wife?

We know that Adam and Eve had other sons and daughters in addition to Abel, Cain, and Seth (Gen. 5:4), and if there was only one original family, then the first marriages had to be between brothers and sisters. Such marriages in the beginning were not harmful. Incest is dangerous because inherited mutant genes that produce deformed, sickly, or moronic children are more likely to find expression in children if those genes are carried by both parents. Certainly, Adam and Eve, coming from the creative hand of God, had no such mutant genes. Therefore, marriages between brothers and sisters, or nieces and nephews in the first and second generations following Adam and Eve would not have been dangerous.

Many, many generations later, by the time of Moses, incest was then prohibited in the Mosaic laws undoubtedly for two reasons: first, such mutations that caused deformity had accumulated to the point where such unions were genetically dangerous, and second, it was forbidden because of the licentious practices of the Egyptians and Canaanites and as a general protection against such in society. It should also be noted that in addition to the Bible most other legal codes refuse to sanction marriages of close relatives.
But here is another issue to consider. If one accepts the evolutionary hypothesis as to the origin of the human race, has that really relieved the issue of incest? Not unless you also propound the idea of the evolution of many pairs of beings, pre-human or whatever, at the same time. No matter what theory of the origin of the human race one may take, are we not driven to the conclusion that in the early history of the race, there was the need for intermarriage of the children of the same pair?

excerpted from The Search for Adam and Eve|John Tierney|Newsweek (1992)

To find Eve, Cann first had to persuade 147 pregnant women to donate their babies’ placentas to science. The placentas were the easiest way to get large samples of body tissue. Working with Wilson and a Berkeley biologist, Mark Stoneking, Cann selected women in America with ancestors from Africa, Europe, the Middle East and Asia. Her collaborators in New Guinea and Australia found Aboriginal women there. The babies were born, the placentas were gathered and frozen, and the tissue analysis began at Wilson’s lab in Berkeley. The tissues were ground in a souped-up Waring blender, spun in a centrifuge, mixed with a cell-breaking detergent, dyed flourescent and spun in a centrifuge again. The result was a clear liquid containing pure DNA.
This was not the DNA in the nucleus of the babies’ cells — the genes that determine most physical traits. This DNA came from outside the nucleus, in a compartment of the cell called the mitochondrion, which produces nearly all the energy to keep the cell alive. Scientists didn’t learn that the mitochondrion contained any genes until the 1960s. Then in the late 1970s they discovered that mitochondrial DNA was useful for tracing family trees because it’s inherited only from the mother. It’s not a mixture of both parents’ genes, like nuclear DNA, so it preserves a family record that isn’t scrambled every generation. It’s altered only by mutations — random, isolated mistakes in copying the genetic code, which are then passed on to the next generation. Each random mutation produces a new type of DNA as distinctive as a fingerprint. (The odds against two identical mitochondrial DNA’s appearing by chance are astronomical because there are so many ways to rearrange the units of the genetic code.)

To study these mutations, the Berkeley researchers cut each sample of DNA into segments that could be compared with the DNA of other babies. The differences were clear but surprisingly small. There weren’t even telltale distinctions between races. “We’re a young species, and there are really very few genetic differences among cultures,” Stoneking says. “In terms of our mitochondrial DNA, we’re much more closely related than almost any other vertebrate or mammalian species. You find New Guineans whose DNA is closer to other Asians’ than to other New Guineans’.” This may seem odd, given obvious racial differences. In fact, though, many differences represent trivial changes. Skin color, for instance, is a minor adaptation to climate — black in Africa for protection from the sun, white in Europe to absorb ultraviolet radiation that helps produce vitamin D. It takes only a few thousand years of evolution for skin color to change. The important changes — in brain size, for instance — can take hundreds of thousands of years.

The babies’ DNA seemed to form a family tree rooted in Africa. The DNA fell into two general categories, one found only in some babies of recent African descent, and a second found in everyone else and the other Africans. There was more diversity among the exclusively African group’s DNA, suggesting that it had accumulated more mutations because it had been around longer — and thus was the longest branch of the family tree. Apparently the DNA tree began in Africa, and then at some point a group of Africans emigrated, splitting off to form a second branch of DNA and carrying it to the rest of the world.
All the babies’ DNA could be traced back, ultimately, to one woman. In itself that wasn’t surprising, at least not to statisticians familiar with the quirks of genetic inheritance. “There must be one lucky mother,” Wilson says. “I worry about the term ‘Eve’ a little bit because of the implication that in her generation there were only two people. We are not saying that. We’re saying that in her generation there was some unknown number of men and women, probably a fairly large number, maybe a few thousand.” Many of these other women presumably are also our ancestors, because their nuclear genes would have been passed along to sons and daughters and eventually would have reached us. But at some point these other women’s mitochondrial genes disappeared because their descendants failed to have daughters, and so the mitochondrial DNA wasn’t passed along. At first glance it may seem inconceivable that the source of all mitochondrial DNA was a single woman, but it’s a well-established outcome of the laws of probability.

You can get a feel for the mathematics by considering a similar phenomenon: the disappearance of family names. Like mitochondrial DNA, these are generally passed along by only one sex — in this case, male. If a son marries and has two children, there’s a one-in-four chance that he’ll have two daughters. There’s also a chance that he won’t have any children. Eventually the odds catch up and a generation passes without a male heir, and the name disappears. “It’s an inevitable consequence of reproduction,” says John Avise, a geneticist at the University of Georgia. “Lineages will be going extinct all the time.” After 20 generations, for instance, it’s statistically likely that only 90 out of 100 original surnames will disappear. Avise cites the history of Pitcairn Island in the Pacific, which was settled in 1790 by 13 Tahitian women and six British sailors who had mutinied on the Bounty. After just seven generations, half of the original names have disappeared. If the island remained isolated, eventually everyone would have the same last name. At that point a visitor could conclude that every inhabitant descended from one man — call him the Pitcairn Adam.

So thus there must be a mitochondrial Eve, and even traditional anthopologists can’t really argue against her existence. What shocked them about Mitochondrial Mom was her birthday, which the Berkeley researchers calculated by counting the mutations that have occurred to her DNA. They looked at the most distant branches of the family tree — the DNA types most different from one another — and worked backward to figure out how many steps it would have taken for Eve’s original DNA to mutate into these different types. They assumed that these mutations occurred at a regular rate — a controversial assumption that might be wrong, but which has been supported by some studies of humans and animals. Over the course of a million years, it appears that 2 to 4 percent of the mitochondrial DNA components will mutate. By this molecular calculus, Eve must have lived about 200,000 years ago (the range is between 140,000 and 290,000 years). This date, published this past January by the Berkeley group, agrees with the estimate of a team of geneticists led by Douglas Wallace of Emory University.