Archive for the ‘Science’ Category
|Chimp vs Human DNA- The “Ninety-Eight Percent” Myth
Monday, August 9th, 2010
As we enter the month of August, it’s time once again for students to head back to school. That being the case, there’s a good chance that in science classes all across the country, as teachers cover the topic of evolution, sooner or later they will make mention of the “98 percent similarity” between human DNA and chimpanzee DNA, thus implying common ancestry. Over the past several years, this idea of 98 percent similarity has been repeated so many times that it is now widely accepted by most people as a “scientific fact.” But is that really the case?
To begin with, it’s really important to understand that this whole idea of comparing DNA can be rather tricky business and we must exercise a great deal of caution when it comes to the conclusions that we draw from the data and how we interpret that data. For example, compare the two sentences below:
“You are going on an all-expense-paid trip to the Caribbean aboard a luxurious cruise ship.”
“You are NOT going on an all-expense-paid trip to the Caribbean aboard a luxurious cruise ship.”
Even though these two sentences have 98 percent homology (similarity), they have opposite meanings- the difference between going and not going! In a similar way, since DNA is all about information, a high degree of similarity between two DNA sequences does not necessarily mean that they have the same meaning or function.
Another pitfall that we must avoid in comparing DNA is that we have to be careful not to assume that genetic similarity necessarily points to some sort of ancestral-descendant relationship or relatedness. After all, some studies have shown that humans and daffodils share a 35 percent genetic similarity. But I don’t think that anyone is prepared to interpret that data to mean that humans are “related to daffodils” or that humans are “over one-third daffodil.”
Getting back to the claim that humans and chimps are 98 percent similar, the most damaging evidence of all was revealed in more recent studies as reported a few months ago in the journal Nature. (see Nature. 463 (7280):536-539) The article’s title alone speaks volumes about what researchers found: “Chimpanzee and Human Y Chromosomes are Remarkably Divergent in Structure and Gene Content.” In other words, chimp and human Y chromosomes are surprisingly different. The results of this more recent research contradicts the initial findings from the 2005 chimpanzee genome project which ultimately led to the idea of 98 percent similarity. As it turns out, one of the underlying problems with the 2005 study was that it was extremely biased toward an evolutionary view. Rather than trying to determine whether or not chimps and humans are related, researchers in the 2005 study began with the assumption that chimps and humans are related. When they began the process of assembly and orientation of the sequences gathered from the chimpanzee genome, they did so based on a map of the human genome rather than basing it on a map of the chimpanzee genome. Taking this approach allowed their evolutionary bias to influence the outcome of the study.
So, the long and short of all of this is that the idea of “98 percent similarity” is a myth. According to the latest, more accurate study, the overall similarity turned out to be 70 percent or less. It will be interesting to see whether or not this latest information is mentioned at all in our high school science classes this year. If not, it should be a reminder to all of us that those who knowingly disallow such information are more interested in pushing their ideology than they are about doing good science.
Tags: 98 percent similarity, chimp vs human, DNA, Science
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Undermining the Basis for Science
Monday, May 17th, 2010
A few years ago, a close friend of mine invited me to join him in attending an afternoon lecture at ASU that was open to the general public. The speaker was a professor of zoology who also happened to be a staunch evolutionist. His lecture that day was dealing with the topic of Intelligent Design. For those who may not be familiar with the term, Intelligent Design (I.D.) is basically the scientific investigation of living systems that reveal striking examples of design, thus implying a designer behind it. Proponents of I.D. do not make any claims as to who the designer is, only that evidence of an intelligent designer is clearly present. As those attending the lecture were about to find out, not only was this professor absolutely closed-minded to the possibility of I.D., he was a cynical opponent to the very notion of a designer.
Throughout the entire lecture, in various ways, he continued to drive home the point that “no REAL scientist would ever allow for the possibility of a designer behind the design.” His presentation included political cartoons that portrayed I.D. scientists as inept, ignorant, ‘pseudo-scientists’ not worthy of serious attention. By the time he was finished, he had left the students with the impression that there are two distinct categories of people when it comes to the origins debate. On one side, you have those who are bright, intelligent, educated people who are smart enough to know that evolution is a ‘fact’ and that there is nothing outside of the material world- especially God. On the other hand, you have those who dare to question evolution, but they only do so because they are ignorant, uneducated, pitiful, superstitious types, most of whom are only pretending to be real scientists. That was his overall message, but the scenario he had presented that day is a false dichotomy.
During the question and answer time, my friend and I pointed out to the professor that if we are expected to take his claims seriously, then what are we to make of someone such as the late Dr. A.E. Wilder-Smith, professor and lecturer, who held three doctorates and authored or co-authored over seventy scientific publications and thirty books that included such topics as the scientific problems with evolutionary theory and the scientific case in favor of a Creator. Furthermore, what are we to make of the growing list of scientists who have recently signed on to a document openly stating their dissent from Darwinism?
Had time allowed, there were many other things that we could have said that afternoon to point out that “the emperor has no clothes”, but the most telling thing of all occurred to me as we were leaving the building after his lecture. As we stepped outside, I looked back and noticed that on the front of the very building that we had just exited, there were several names engraved across the top of the building for all to see. The list included such notable names as Pasteur, Newton, and Kepler. It is no accident that the architect intended for those names to appear on that building because those names represent some of the ‘Founding Fathers’ of science. More importantly, those very same scientists all shared something in common- they all held the view that there IS a Creator behind the creation and that He has revealed Himself through that which He has made. More than that, they also felt that through scientific investigation of His creation they would be able to understand more about Him.
Maybe it’s a good thing that we didn’t get a chance to bring this to the attention of the professor. Had we done so, he may very well have demanded that the university plaster over those names in an attempt to expunge their memory from science’s ‘Hall of Fame’. But, try as he may, that professor will never be able to blot out the enormous contributions that they have made in laying the very foundation of modern science- the same science of which he has been a beneficiary as well.
Tags: and Kepler, ASU, creation, creationism, Dr. A.E. Wilder-Smith, evolution, Intelligent Design, Newton, Pasteur, Science, scientist
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In today's world, there is a great deal of confusion when it comes to matters of truth, meaning, morality, our origin, and our destiny. The purpose of Renewed Thoughts is to bring clarity to such issues by examining them in light of a Biblical worldview, using the tools of science, philosophy, and critical thinking.