When I was in college, one professor started off his science class by announcing, “Half of what I teach you is not true. The problem is that I don’t know which half.” His point was that though he was teaching what was thought to be true, further scientific research would show that much of it was not true. Sometimes it is just that things are more complex than we first realized. Other times there may be a radical change in how we understand things.
Limits of scientific knowledge
Science has become somewhat of an idol in our culture. Some have promoted it as the ultimate method for finding truth. It has been suggested that it is the source for “salvation” from disease and death and holds hope for the future of mankind. According to the Bible, God is the ultimate source of truth, salvation, healing, and life. While science is a useful gift from God, it should not be worshipped in the place of the One who gave it to us.
The scientific method is a valuable tool for finding answers to questions about the world around us. Critical thinking is also important. This was emphasized in graduate school where we had a class devoted to reading published scientific papers. We had to determine if the author’s conclusions logically followed from his experiment. We were challenged to think of other possible explanations for the results and to suggest experiments that might determine which explanation was correct. I remember reading many well-thought-out articles where the author used good scientific reasoning. I was a bit surprised when I read other articles where the conclusions did not follow from the research; it seemed the author had already come to his conclusions and was trying to fit the research into his pre-existing viewpoint.
Science will always be limited because it is a human endeavor. Humans are fallible. Temptations can affect scientists just like they do other people. There is pressure to find important results, gain prestige in the field, and have a secure job. Sometimes this pressure can influence a person to compromise honesty and even the search for truth. Additionally, sometimes scientists don’t know the right questions to ask when searching for answers. This can be especially true in biology and medicine because life is so complex.
Science is also very limited in how much it can help us understand the past. The study of the past is history, not science. Sometimes science, as in forensics, can provide some clues. However, an accurate understanding of what happened in the past is best obtained through an eyewitness, someone who was actually there and can tell us what happened.
What wasn’t quite true has given way to something even more interesting
Some people get frustrated when they realize that the “facts” taught in biology class today might turn out to not be true tomorrow. I have the opposite reaction. It reminds me of how much we have left to learn. It excites me to know there are plenty of answers out there waiting to be found. I find this search exhilarating (Proverbs 2:1–5; 25:2). In my experience, the truth turns out to be even more interesting than what we had originally believed to be true. It tends to leave me even more in awe of the design and wonder in the world around us. Here are a few examples.
One gene produces one protein for one trait—not really
When I took biology we learned that a gene was a stretch of DNA that coded for a protein and that protein was responsible for a trait, such as the color of peas. This is still a useful model for someone first learning about genes. However, the truth turns out to be far more interesting.
It was quite a surprise when the completion of the Human Genome Project was followed by the suggestion that there were less than 25,000 human protein coding genes.1 It is estimated that humans can produce at least 1,000,000 different proteins.2 The discrepancy is a result of the efficient organization of our genes. Many genes code for a number of different proteins.3 So how do our bodies know which protein to produce from a gene? How do they produce the right amount in the right place at the right time? Those questions will keep researchers busy for years as they continue to uncover details about the awesome design of the human body.
There are examples where a difference in a protein can make an obvious difference in a creature. For example, there is a gene that influences coat color in mammals.4 One allele for that gene, which codes for a defective protein, results in the yellow color of the Golden Retriever.5 These animals cannot produce the darker pigment known as eumelanin, so the effect of the mutation is quite dramatic. Still, there are many other genes that can influence coat color in mammals.6 These proteins do not exist in isolation, but are part of astoundingly complex biochemical pathways. Some proteins are important in multiple pathways. The design of life is so intricate and complex that we have only begun to understand it.
A species is characterized by a specific chromosome number—sometimes
When I was in college chromosome number was viewed as being very constant within a species. Many times it can be. However, I was puzzled by the fact that horses, donkeys, and zebras have different chromosome numbers. As a creationist I believed they belonged to the same created kind. How could chromosome numbers change without killing the animal, especially if it was just the result of some genetic accident?
It was years later when I searched the scientific literature that I began to find answers.7 Sometimes chromosomes undergo rearrangements, such as two fusing into one. On the popular level these are assumed to usually be associated with problems such as infertility. While in some cases they have a strong negative effect on fertility, many times they do not. Ruminants (cattle, sheep, antelope, and deer) and rodents seem to be especially prone to such rearrangements.8
I found that the rearrangements were too well controlled to reasonably be purely genetic mistakes.9 Chromosome number is not as static as I had been taught. Instead, chromosomes were designed to be able to vary somewhat, and this variation appears to have important mechanisms controlling it that are yet to be fully understood.
One important point here: changes in chromosome number do not change one kind of animal into another. In promoting evolution, some have claimed that evidence suggesting human chromosome 2 was the result of a fusion emphatically proves humans came from apes. The problem is that if a fusion occurs in ape chromosomes, the animal will still be an ape. Many humans have been identified with fusions, and they are still human. Converting ape chromosomes to human chromosomes involves far more significant changes than a simple fusion.10
Identical twins are genetically identical—almost
Identical twins develop from the same fertilized egg. Early on as the cells divide they split apart, resulting in two separate embryos that develop as two separate babies. In theory, they should be genetically identical since they both developed from the same fertilized egg. Recent research has suggested this is not quite the case.11
Are these genetic differences normal or a sign of disease? Sometimes they can be a part of a disease process. In fact, many cancers are associated with rapidly dividing cells that have a number of genetic changes in them compared to normal body cells. Other times genetic differences that arise are seen in normal people. In certain genes, genetic changes appear to play an important role in allowing for adaptation and survival in our present world.12
What about evolution?
The teaching of evolution hasn’t changed all that much since I was in school. It is mostly taught using two different meanings of evolution and blurring them together to imply that there is scientific support that all life has a common ancestor. However, the basic premise that all genetic changes are just the result of copying errors is getting harder to defend.
There are types of changes that do occur. For example, birds have beaks and there can be differences in beak size and shape. Over time, the average size and/or shape may change in a population of birds. Similarly, animals have the ability to produce pigments and the amount of pigment may change if a mutation, defined as a change in the DNA sequence, occurs.13 For a variety of reasons, individuals with a particular mutation affecting coloration may be very common in a group of animals.14 There are many of these types of changes and biology books refer to this as evolution. It has been observed.
It is one thing to notice that an existing trait can be adjusted through mutation.15 However, it is quite another thing to jump to the conclusion that entirely new traits16 can come into existence through the types of mutations that are known to occur. The details currently understood about genetics and mutations do not imply that all life shares a common ancestor.
One reason people sometimes fail to see this is that they sometimes think of life as a specific DNA sequence. There is always a theoretical path that can be taken to get from one sequence to another. This is just a matter of inserting, deleting, and substituting. This does not imply that such proposed changes could actually occur in a living organism. Many genetic changes are not well tolerated or are even lethal. There are some proposed changes to the DNA sequence appear quite plausible and result in adaptation within a created kind. Other proposed changes are implausible, since there is no reason to believe an organism could live and reproduce with such sequence changes occurring.17
According to the popular view of molecules-to-man evolution, the only mechanisms that operate are time, chance, and natural selection. As more research is done, this view is getting more difficult to defend in a logically coherent fashion. For example, a series of proposed DNA sequence changes within monkeys, which are quite plausible and would account for adaptation within the created kind, are assumed by evolutionists to be the result of chance mutations and natural selection. The problem is that the same series of changes appear to have occurred in two different populations of monkeys, which is highly unlikely if only chance processes are involved. Also, it does not appear that natural selection can reasonably account for these mutations becoming fixed, that is replacing the original form of the gene, even if they had arisen by chance.18
Since I was in college it has been discovered that crossing over in chromosomes is not just an unusual accident, but is a normal, well-controlled occurrence with numerous specific enzymes involved in regulating the process. Other mechanisms affecting DNA sequence, such as gene conversion, are also known. Insisting that such well-developed mechanisms could arise by chance is incredibly counterintuitive. If design was a problem before we understood such details, then it has grown to be a significantly larger problem today.
Call for Christians to engage in science
Science is one critical area that Christians need to be involved in today. The biblical worldview provides the basis for modern science.19 There is a reason to believe we can find valuable answers as we search. Christianity also provides a sound basis for morality. If our goal is to honor God in all we do, it provides a basis for holding on to honesty even if it appears negative consequences will follow. It gives us a reason to be thorough in our search, working hard to honor God (Colossians 3:23). Finally, it provides a motivation, through the dominion mandate (Genesis 1:26-28) and the command to love our neighbor (Matthew 22:37-40; Galatians 5:14), to understand the world around us so we can use the knowledge to properly manage our resources and benefit mankind. As more Christians with a solid biblical foundation heed the call to enter scientific research, they can make valuable contributions. While the primary reward is honoring God, in the process they can contribute to the well-being of society, bring a stronger Christian witness to the science laboratory, and find answers that will eventually find their way into the course content of the classroom.