One of our brothers at Gracepoint Berkeley, a Ph.D. structural biologist in UCSF, has given us a brief explanation of evolution below that might be helpful in understanding the issues with evolution that have been mentioned in our Truth Project.
I. What is Evolution?
Darwinian evolution is defined as the change in the gene pool of a population from generation to generation, leading to new adaptations and the emergence of new traits that ultimately lead to the genesis of new species. Although these changes in any single generation are small, the belief is that the changes that give a competitive edge to an individual or population accumulate over the course of multiple generations. Therefore these traits add up over time as those individuals with these ‘good’ changes out-competed those without. This mechanism is called natural selection or commonly known as “survival of the fittest.” Proponents of evolutionary theory point to the similarities between organisms and suggest that all species have descended from a common ancestor.
Figure 1 – Two classic icons of evolution. A) The picture of evolution that depicts the evolution of man from ape. B) The different colors of the peppered moths that give selective advantage of a certain colored moth in different environments.
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2. The problem with Natural Selection.
Natural selection is one of the cornerstones of the naturalistic worldview, in which all creation and living things are believed to be the result of random chemical and physical events that have led to the addition of complexity over time into the diverse kingdoms of life we see today. One can say that it is one of the pillars of the church of science & naturalism and places its trust and faith on the blind and unguided chemical/physical processes to bring forth life and the millions of different species we see today.
3. Technical problem with evolution – Irreducible complexity:
Since evolution is a gradual process in which slight modifications produce advantages for survival, it cannot produce complex structures in a short amount of time. Darwin recognized this shortcoming to his theory and stated this disclaimer to his theory:
"If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down." --Charles Darwin, Origin of Species
The fact is, mutations may gradually build up and modify complex structures, but it cannot produce them in their functional form without meaningless and non-functional intermediate steps. Mutations may change function, but in most cases, it is detrimental to life and leads to the loss of function. Furthermore, mutations cannot bring about the formation of multi-component complexes that are involved in almost every molecular process in our cells and organs required for life. A great illustration of the complexity of even a single response in the cells can be visualized in a great computer animation called “the inner life of the cell” (http://multimedia.mcb.harvard.edu/anim_innerlife_hi.html). It is not far-fetched to compare a single cell to a large bustling metropolis, with thousands of different functions and signal networks interacting at the same time. With the incredible complexity of a single cell, it takes a huge amount of faith to conclude that this complex system have derived from unguided and blind mutational changes.
The concept called irreducible complexity was developed by biochemist Michale Behe to describe this problem of the genesis of complex biological systems. Simply put, everything is there and it works, or something is missing and it doesn’t work.
Figure 2 – The mousetrap |
The concept illustration for an irreducible complex system is the mousetrap (Figure 2). This device contains 5 interdependent components to work: the wooden platform, the spring, the hammer, the holding bar, and a catch. Each of these components is absolutely essential for the function of the mousetrap. Remove any of the parts, and it can no longer catch mice. This example implies that an irreducibly complex system cannot come about in a gradual manner. A step-by-step approach to constructing such a system will result in a useless system until all the components have been added. The system requires all the components to be added at the same time, in the right configuration, before it works at all.
Some of the biological examples used by Behe are the bacterial flagella, the blood clotting mechanism in humans, and the eye. In each of these cases, either you have everything and it works, or you take away something and it doesn’t. One can take any known molecular machine or signal system in the cell and it runs into the problem of irreducible complexity.
Figure 3 – Illustrations of the irreducible complex systems
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Blind evolution, as described by Darwinian theory, cannot produce complex structures in a single generation, as would be required for the formation of irreducibly complex systems. Even the production of one or a few of these proteins at a time is not only improbable, and it would provide no advantage to the survival of the individual because those few proteins would have no function. Darwin recognized this as a weakness to his theory when the cell was understood as a sac of goo, and the advances we are making in biological sciences today only add to the incredible complexity of life that makse belief in Darwinian evolution a feat of great faith indeed.
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The following question is regarding human evolution, in light of the Truth Project from 7/12:
Some scholars point to various homo species' fossils as supporting evidence for human evolution. What is the truth behind such evidence? How are these evidence discredited?
One way of looking at 'bone' evidence for evolution is to always remember that it is very speculative data. Physical anthropologists who make a living analyzing bones and coming to conclusions based on it are on very shaky ground. I personally think it is one of biggest areas of science where colleagues have given a lot of grace in the analysis and interpretation of the data. Safe to say, scientists in physics, mathematics, biophysics, biochemistry, etc. are held to a much higher standard of reproducibility and robustness of data before anything is published. My take on it this phenomenon is that it is so important to the Naturalistic worldview and it fits their expected and desired view of nature. Also, many of these discoveries are just part of a jaw bone mixed with a part of a leg bone and many other parts are reconstructed, adding to the speculations. There have been many grand announcements of having discovered the 'missing link' in the evolution of homonids into humans, starting with Lucy, but I think one can always look at the work of bone scientists with a large grain of salt.
This is a puzzle which is related to the issue of evolution, I think, and the previous comment: how should we understand the genealogical accounts in the Bible? I ask because Genesis specifies a lot of numbers, and when you do the math, you get something like 2000 years from Adam to Abram. Assuming 2000 years from Abram to Jesus and another 2000 to us, that's only 6000 years back to the first man. Even if you assume that Adam may have lived for 100s of thousands of years in the Garden, and that his age accounting only began after the fall, you have the issue that even if Adam/Eve had had lots of children during that time, there was supposed to be no death, and so we should find no 100,000 year old homo sapien fossils, especially ones bearing culturally motivated marks. To what extent are the pre-Abram genealogical accounts subject to interpretation? I ask because things there seem to stated in relatively plain terms, like "when so-and-so was 30 years old, he had two sons," etc. which suggests that generations are not being skipped.
I haven't yet seen a clear-cut explanation from any biblical scholars regarding how long human beings have really been on the earth. Daniel may be better at elucidating this issue, but I'll give it a shot.
If we follow the Bible's genealogy, it really is only about 6,000 years, which leads young earth creationists to argue that the earth must only be about 6,000 years old. The scientific evidence seems to suggest the earth is much older than that. Moreover, it seems that human beings have been on the earth for at least 150,000 years, at least from the fossil evidence. It's hard to match this with the bible, and that's kind of disconcerting if we truly are made in God's image.
I think one thing that can be said is that the fossil evidence, as John already pointed out, is highly speculative. The dating methods are actually pretty imprecise. Something that I find very interesting, actually, is that if we look back in history, the earliest cities started popping up about 6-7,000 years ago, and in Genesis it records Cain as building a city in the land of Nod.
As a scientist and as a Christian, I'm willing to say that we don't have all the answers on either side. Given the evidence of cities popping up right around the time of biblical creation, I'd say that we can't just discount the biblical account outright.
@jhong: daniel might be able to give a more thorough explanation, but i wanted to chime in with a quick response: the genealogies in the bible are not necessarily exhaustive. in fact, the original hebrew word can be more accurately translated as "fathered an ancestor of".
for a very detailed paper, see:
http://www.reasons.org/resources/non-staff-papers/the-genesis-genealogies
P.Jonathan
http://joongwlee.wordpress.com
I think it is important to mention also that belief in natural selection does not commit one to a naturalistic/physicalist position. There is nothing logically incoherent with the notion of a supernatural entity employing natural selection/ evolution as a means to producing species. However, the main problem to think about is if it is in fact logically coherent with the Christian God/ biblical accounts.
Furthermore, there are some Christian philosophers who argue that natural selection undermines the naturalistic position (Alvin Plantiga being one of them), and that natural selection/evolution is more (logically) compatible with a theistic position.
Then we have other Christian philosophers/theologians rejecting evolution altogether (William Dembski, Behe). As it stands, evolutionary theory doesn't hold as much strength as let's say our theory of gravity. Due to the historical contingencies (because of evolution) that biology rests on, many have argued that there are no scientific laws in biology. Because of this, it leaves a lot of room for debate on the theory of evolution. Philosophers of Biology/biologists are still nitpicking on the "circular" concept of fitness, the definition of species, the definition of populations. Thus, when a atheist/agnostic claims that evolutionary theory is a theory just like the theory of gravity is a theory (in an attempt to show that evolution holds as much strength as a theory we do not doubt: gravity) he/she presupposes that the theories are equal in strength.
I believe that theist still has many options available in this point of time in the field of biology. Any empirical evidence found through biology in the end can simply be referenced back to a creator who leaves no direct empirical evidence of Himself.
I have still yet to hear how scientists/philosophers aim to reconcile the deterministic theory of evolution (genetic drift aside) with the stochastic theory of quantum mechanics. String theory?
There is ample evidence accepted by the scientific community that shows that the flagellum, blood clotting, and the eye are not irreducibly complex. Their ancestral forms have been discovered and the mechanism of their evolution have been explained. I'll leave it up to you to read up on that.
Anoymous,
That's really interesting. Can you provide some articles explaining how these discovered ancestral forms solve the issue of irreducible complexity?
Finding a primitive eye, for example, does not solve the problem of irreducible complexity of biochemical systems that comprises the complex systems.
For a more exhaustive treatment of this topic, you can look at the article: http://www.detectingdesign.com/flagellum.html
I have a question regarding the teleological argument. I know it is not discussed in this post, but I figured that this is somewhat relevant. George H. Smith argued that it is impossible to conclude that life is designed. Christians say that life is designed and not a product of random chance. Yet we also acknowledge that all of nature is designed by God. This poses a problem in differentiating between what is designed and what is not. How can we conclude that life is far too complex, and therefore designed, when we lose nature as a reference point for chaos since nature itself is designed?
Just in case I did not make my question clear, here is a excerpt of George Smith's book, Atheism: The Case Against God.
"Consider the idea that nature itself is the product of design. How could this be demonstrated? Nature, as we have seen, provides the basis of comparison by which we distinguish between designed objects and natural objects. We are able to infer the presence of design only to the extent that the characteristics of an object differ from natural characteristics. Therefore, to claim that nature as a whole was designed is to destroy the basis by which we differentiate between artifacts and natural objects. Evidences of design are those characteristics not found in nature, so it is impossible to produce evidence of design within the context of nature itself. Only if we first step beyond nature, and establish the existence of a supernatural designer, can we conclude that nature is the result of conscious planning."
How do we respond to this?
Good question.
I would say that it is possible to detect design of an object within the context of a designed background. The objection quoted above seems to be ignoring the obvious fact that there can be different levels of design.. Let's say I place a computer in a house. And I put someone in there who has never been outside of the house.. Does that mean this person would not be able to recognize that the computer seems to be designed, since she lives inside another designed thing (i.e., the house)? Of course this person would be able to tell that a computer seems designed, it is on a different level of design than the background house. Hope that's clear -- as far as your question is concerned..
Now, Smith's objection is saying something more fundamental. Smith is saying that there is no way (in the above example) for someone to claim that the house is designed, if the person has lived inside the house his entire life, since we can only tell design in the context of an undesigned background. This sounds almost convincing, but I think he's making a flawed argument. The person, for exmaple, could still experience randomness within the house, and understand what true randomness looks like. If the person drops the vase in the house and it breaks into pieces, for example, he would see what randomness looks like. In other words, just because a person has lived inside a designed object all his life, that does not mean that he has NO idea what randomness looks like. And after this imaginary person gets a pretty good idea what randomness looks like, he can start to suspect that the house he lives in is not a product of randomness.
Likewise, to say that nature is designed does not mean that there is no such thing as randomness within nature... which seems to be how Smith is arguing for his case. He is assuming that if nature is designed, then there cannot be any randomness or less designed objects within that nature... Thus we have lost the point of reference. But obviously, that would be over-simplifying the concept of "design" by flattening all designs to be equal complexity.
Hope that makes sense.
Let's clarify a little further.. To be my own devil's advocate, I could imagine George Smith responding to my previous comment by saying that if NATURE itself is designed, then there can't be any true randomness... Therefore since nothing is random or chaotic, we have destroyed our own reference point for detecting design.
In response, I could argue against his premise that if nature is designed, there cannot be randomness. I think it's faulty to assume that design cannot contain laws of randomness.
However, let's actually grant Smith his point. Let's assume, for a moment, that if nature is designed, then there can't be any true randomness.. But even upon granting Smith's point, I would say you can still maintain a reference point. All you need is different levels of complexity or design. A computer is highly designed. A computer that has been dropped and broken into 100 pieces is still designed, but now it's "less" designed. A little plastic doorknob is lower on the design scale than a working computer. And let's say all these items are found inside a cave that you don't konw if it's designed or not. Yet, you can still recognize the computer to be designed, even though you're not comparing it to anything that is truly chaotic or undesigned. All you need is different levels of design, which obviously exists in nature. And Smith seems to be ignoring that fact.
@johnkorea - please look up the topic of hominid evolution for details of bones found. Your claim that many discoveries are of a jaw bone mixed with part of a leg bone, and to refer to Lucy the way you have betrays your ignorance of the subject. Your ad hominem attack on physical anthropologists in an attempt to discredit them is unfortunate, but not an unusual tactic. If you look at the hominid record in the creationist literature, you will see that they do not agree amongst eachother on which is human and which is an ape. Can you explain that? Common descent can. Please also try to explain human chromosome #2 in light of creation. I doubt that you will educate yourself on this topic because it will require more mental gymnastics to explain it away. It is easy to post comments on this site where you are fairly well insulated from critiques and people will accept your opinions as authoritative.
Please do read up on the blood clotting cascade, flagellum, and development of the eye. Dr. Kenneth Miller, a Catholic molecular biologist, discusses this in great detail. Also look up Dover Trial in which Dr. Behe demonstrates that his opinions are not entirely based on knowledge of the scientific literature.
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