The molecular clock just went off-line.
The first direct measurement of human mutation rates ever done, published in Nature Genetics, contains surprises which call molecular clock assumptions into question and prompt some re-thinking of our genetic understanding. Analysis of data from two families in the “1000 Genomes Project” database suggests that humans mutate much more slowly than predicted and in surprisingly unpredictable and inconsistent ways.
In each case, the genomes of one child and his/her parents were analyzed. The first challenge was to determine which genomic differences represented mutations and then which of those were inherited. Only mutations in the parents’ germ cells can be inherited. While about 1600 non-germline mutations were found, only 49 mutations were inherited by one child and only 35 by the other.1 Other studies confirmed an average of around 30 to 50 mutations passed on per child.
Human mutation rates have previously been estimated by assuming that humans and chimps evolved from a common ancestor on an evolutionary timescale of millions of years. Human-chimp differences are analyzed to decide which differences represent presumed mutations. Finally, by calculating how many mutations it takes to make a person, the rate of mutation within the evolutionary time frame is determined. Thus the molecular clock is a figment of evolutionary imagination. And this new data suggests that the clock’s estimates are about three times too fast. Hanging onto the notion of a common ancestor, study co-leader Dr. Philip Awadalla says, “In principle, evolution is happening a third as slowly as previously thought.”2
The surprises don’t end there. Genetic dogma has held that fathers, because they continually manufacture sperm, should pass on mutations much faster than mothers. This phenomenon is called male mutation bias. However, while one child inherited the expected 92% of its mutations from the father, the other only received 36% from its father. While the researchers still maintain that males generally produce more germ cell mutations per generation than women, Awadalla now adds that “the mutation rate can be extraordinarily variable from individual to individual.”
The dramatic variability of human mutation rates also increases the danger of misdiagnosis of genetic diseases. As Dr. Awadalla says, “The variation in mutation rates that we observed is of potential clinical importance, as it suggests that the risk of misdiagnosing a [de novo mutation] as being pathogenic could vary substantially between individuals.”1
Additional studies of many family genomes will be needed to confirm this data and answer additional questions. For instance, were these mutations sporadic occurrences in the germ cells of the parents or did they exist in all of the germ cell lines? Only analyses of multiple offspring can provide data for those kinds of calculations. Furthermore, why do people mutate at such different rates? Do they have inherently different abilities to repair their own mutations? Does the environment or the age of the parent play a role? Human obstetrical data show that the age of the mother’s ova is significant. But what about the mutation rate of the father?
Future investigations should prove instructive. Yet notice that worldview bias influences interpretations of the basic facts. The facts reported here show that humans mutate more slowly than previously thought. The evolutionary worldview assumes that the common ancestor must therefore be pushed back further into the past. The creationist worldview, not accepting that a common ancestor ever existed, is not surprised that a molecular clock calibrated by evolutionary assumptions cannot be trusted.
The priesthood of science discourages people from thinking for themselves.
Ever since Louisiana passed a law allowing teachers to “use supplemental textbooks . . . to help students critique and review scientific theories,” those who fear such academic freedom have clamored for its repeal. The latest attack has come in response to Minnesota Congresswoman Michele Bachman’s public support for Louisiana’s legislation.
A well-known theistic evolutionist, Dr. Karl Giberson, recently posted a blog practically declaring the priesthood of scientists. Of course, in that scenario, a scientist who holds to a different interpretation of the evidence would be a heretic. Such scientists are commonly accused of no longer being real scientists.
Giberson assures us that we as Christians should stop thinking critically about issues the “scientific community” has already decided for us. He says:
In The Language of Science and Faith Francis Collins3 and I cautioned our fellow Christians against holding out hope that there is a real alternative to accepting the consensus of the scientific community, especially as we see no need for Christians to be uneasy about evolution in the first place.
Furthermore, Giberson says it is “disastrous” to suggest high school students be allowed to critically analyze the scientific interpretations presented to them. He proclaims that “critical thinking about sources and expertise is essential in navigating the complexity of our modern scientific world.” Yet he is afraid that allowing high school students to exercise that skill outside the bounds set by the “scholarly community” will “send the message that there is no such thing as knowledge.”
Giberson states that Congresswoman Michele Bachman’s opinions about evolution are “of no value.” Why then, we might ask, in the Michael Zimmerman post to which he links,4 is so much made of high school student Zack Kopplin’s opinions? Does the high school student have some special expertise? Or for that matter, why are scientific forums still quoting Hillary Clinton’s statement5 that “I believe in evolution. . . . I am grateful that I have the ability to look at dinosaur bones and draw my own conclusions. . . . [Antibiotic-resistant bacteria6 are evidence that] evolution is going on as we speak.” Does Mrs. Clinton have more scientific expertise than Congresswoman Bachman?
Answers in Genesis has never suggested that teachers of any persuasion be forced to teach creationism but rather has always maintained that students and teachers should have the academic freedom to critically examine scientific facts and the worldviews by which they are interpreted. There is nothing “anti-intellectual” about exercising discernment, but there is something very frightening about being told to hush and let others do our thinking.
Truth is not determined by the majority vote of anybody, not even a “consensus of the scientific community.” Truth is found in the Word of God. And while worldview-based interpretations of scientific facts may disagree with the Bible, the actual facts themselves never will. 1 Thessalonians 5:21 commands Christians to “Test all things; hold fast what is good.” The authority behind that command outranks Dr. Giberson.
Organic chemistry lab in a meteorite sparks speculation about the origin of life.
No one is talking about life in outer space this time. But examination of the Tagish Lake meteorite which fell on British Columbia in 2000 has prompted proposals that earthly life got its building blocks from chemicals birthed in the early days of the solar system. Planetary geologist Christopher Herd proclaims, “What we're seeing are the ingredients of life.”
Meteorites are classified according to their chemical composition. Many contain evidence of chemical reactions involving water. About 5% are classified as carbonaceous chondrites. Carbonaceous chondrites are believed by those who accept the nebular hypothesis to reveal much about the chemical soup of the proto-solar system.
Herd’s team found twelve different amino acids in the meteor as well as chemicals seen when heated organic compounds react with water.7 They believe that the 850 grams of fragments are uncontaminated because the collector kept them in a plastic bag in his freezer for the six years it took to negotiate a price for the valuable rocks. (Since the amino acids present are not the left-handed molecular form found in living things, and since one is a type not found in proteins, the absence of biological contaminants seems reasonable.)8
Organic compounds are not unique to earth. But the investigators are excited because the products of several steps in chemical reactions are represented in the meteorite. The investigators suggest the heat energy to drive chemical reactions between minerals and the water frozen in the rock came from radioactive9 decay.
Notice that there has been no claim that these amino acids have been assembled into proteins or organized in any meaningful way associated with life. (Living organisms contain a genetic code, which instructs cells to assemble amino acids into proteins.) The claim here is rather that the amino acids—molecules of “prebiotic importance”—may have reached earth as a result of chemicals knocking around in the nebula that supposedly spawned our solar system.
We should not be surprised to find the chemicals needed to assemble living things in the non-living components of earth and space. God created those elements and molecules and the chemistry that governs their reactions. Therefore, finding amino acids along with chemically related substances is no surprise. God’s eyewitness account of the solar system’s birth tells us that on the fourth day of creation, having already made the earth, He made the sun and moon. And that took place only about six thousand years ago.
Cryptic variation and preadaptation—fancy words for the obvious.
Evolutionary biologists from Zurich say they have the first “direct evidence” for ideas that have “been around for a while.” These ideas, accepted without proof since the mid-twentieth century, were the logical explanation for “how complex traits, seemingly far too complex to be explained by one or a few mutations, could arise.”
The idea that mutations can randomly accumulate without consequences or advantages, evading the judgment of natural selection, is called cryptic variation. When conditions develop that make that random set of mutations useful, that’s called preadaptation. In other words, organisms with some lucky mutations are ready for certain challenges. And those organisms that survive the challenges and reproduce are said to have evolved.
The researchers claim to have provided “concrete experimental demonstration” of these principles. Eric Hayden and Andreas Wagner “evolved ribozymes in test tubes of chemicals, then moved them to a new chemical substrate, a shift analogous to requiring animals to suddenly subsist on a new food source. The ribozymes that flourished were those that had accumulated specific sets of cryptic mutations in their former environment.”
Ribozymes are enzymes made of RNA instead of amino acids. RNA is made of nucleotides, like DNA, but is single-stranded. Ribozymes, like most enzymes, function in part due to their particular geometric shape. That shape is largely determined by the interaction of the nucleotides comprising the ribozyme. Some ribozymes are able to copy themselves, and copying mistakes are analogous to mutations.
So when the researchers put the ribozymes into a new environment, those ribozymes whose mutations best equipped them to survive did so. The survivors could then be copied, so the new population had ostensibly “evolved.” But had it? The ribozymes were still ribozymes. They were not some other kind of molecule, just variations of the original.
The researchers point to this as proof of the mechanism of bacterial resistance. Yet bacterial resistance is no more evolution today than it ever has been. Many genetic possibilities exist in the genomes of organisms, and mutations add to the variety by eliminating some of the existing information. In addition, bacteria are able to receive additional genes from other bacteria. If the mutants or variants which happen to be prepared for new challenges are around when those challenges strike, they survive and reproduce. The new population results from a reshuffling of pre-existing information. That’s not evolution; it’s just natural selection. This is the mechanism God put in place to produce genetic variability within the created kinds.
Statistics suggest a way for eukaryotic mutants to leap over fitness valleys.
Statistical analysis of the proximity of point mutations has suggested a mechanism by which eukaryotic cells could acquire a group of mutations all at once. “A similar phenomenon had been observed in bacteria,” says Dr. Matthew Hahn. “And the idea that this might be happening in eukaryotes has been around for a while. We are the first ones to use exhaustive genomic studies to show it’s actually happening, and happening in a big way.”
“An organism could improve its fitness if it acquired multiple mutations that would each reduce fitness if they occurred individually,” adds graduate student Schrider. "The less-fit intermediate states would be eliminated by natural selection. Cases like this are referred to as ‘fitness valleys.’”
Thus, a group of mutations might produce a desirable change in an organism, but any one of those mutations individually could be harmful. Dr. Hahn is proposing a mechanism by which all the needed mutations could be acquired at once, avoiding the unfit intermediate state. His group analyzed the genomes of yeast, roundworms, a plant, and humans. They found that about three percent of mutations were near other mutations. Dr. Hahn believes such “multi-nucleotide mutations (MNMs)” have “a near-100 percent likelihood of being caused by the same mutational event.”
However, he does not know of any actual examples of “valley leaping.” While a defective DNA polymerase molecule might make a series of errors, he does not know whether the MNMs he has found conform to that mechanism.
The bacterial analogy to which he refers is the horizontal transfer of genomic islands, which seems to be a way God designed for bacteria to exchange information. However, bacteria do not acquire information to become anything other than bacteria.
Likewise, even if eukaryotic cells from yeast, roundworms, plants, and humans happen to acquire a bundle of genes that leap over a fitness valley, those cells will still be yeast, roundworm, plant, and human cells. The change will be horizontal, not vertically up the evolutionary ladder.
Editor:
A May 30 editorial leads readers to the wrong conclusion about the proposed Ark Encounter attraction in northern Kentucky. Taxpayers, contrary to what was stated, will not see their money used to build or operate the Ark Encounter. No money will be taken out of the state’s budget to fund the Ark.
If the Ark meets attendance goals and sees tourism dollars flow into the state, it will receive partial rebates on sales taxes paid by its visitors. At the end of an operating year, the money going back to the attraction will be from those who chose to visit; no unwilling taxpayer will subsidize the Ark. Thus, there is no establishment of religion. Neither is anyone being forced to visit and hear about the history of the Earth according to the Bible, including its account of the Ark.
It’s too bad the Times wasn’t able to better fact-check its editorial.
Mark Looy
Chief Communications Officer
Answers in Genesis
http://www.answersingenesis.org/articles/2011/06/18/news-to-note-06182011