Chapter FourExamples of DesignHuman artifacts (man-made objects), such as the mousetrap, exhibit irreducible complexity; therefore, we know intelligent action caused them to come into existence. Dembski concludes, “Therefore, biological systems that exhibit irreducible complexity are likely to be designed” (Dembski 2003a, p 1).
The cell exhibits the same irreducible complexity as the mousetrap. How do evolutionists explain its existence? Cell biologists Franklin Harold and James Shapiro state, “There are presently no detailed Darwinian accounts of the evolution of any biochemical or cellular system, only a variety of wishful speculations” (Dembski 2004a, p 16).
The Cell
Cells are the basic units of life. Our bodies are made up of many different kinds of cells. Each cell is composed of a variety of parts that function in various ways. Figure 4.1 on page 11 is a diagram of an animal cell. In Darwin’s Black Box, Behe (1996) lists the parts of the cell and their functions as follows:
Ø Nucleus: holds DNA
Ø Mitochondria: produces cell’s energy
Ø Endoplasmic reticulum: processes proteins
Ø Golgi apparatus (or complex): stores proteins that are being transported
Ø Lysosome: contains enzymes that help the cell digest various materials (Carpi 1999).
Ø Secretory vesicles: stores secretions such as hormones before they are sent from the cell (Cells Alive 2004)
Ø Peroxisome: helps body digest foods, such as fats
Because each part of the cell is sealed off from other parts by a membrane, the question arises: how do materials the cell needs get past the membrane barriers and into their special compartments?
The cell moves proteins into various compartments using three methods (Behe 1996).
I. Gated Transport - Gate opens and closes to allow or block proteins from passing through membranes.
II. Transmembrane transport - A single protein is guided through a protein channel through the cell membrane
III. Vescular transport - Protein is transported by “containers”
Gated transport and transmembrane transport are essentially the same. The only difference between the two is the size of the channel the proteins pass through: gated transport uses a large channel; transmembrane transport uses a small channel (Behe 1996).
In order for gated transport to work, several components must be in place:
Ø Proteins must send out signals in order for the “gate” to recognize the proteins and allow them to pass from one place to another.
Ø On the other side of the gate, enzymes must have receptors in order to recognize the proteins’ signals. Once the enzymes recognize the signals, the gate is opened.
Ø Proteins must have a channel to pass through. However, if a channel allows all proteins to pass through, then all compartments would contain the same materials (Behe 1996).
All components that allow these processes to take place must exist at the same time, not gradually. Therefore, this system is irreducibly complex; and Darwinian evolution cannot explain how this system came into existence.
According to Behe (1996), vesicular transport is more complex than gated transport and requires six components in order to function. If all six parts are not in place, the system either fails to function or the proteins fail to reach their proper destination.
This is a brief explanation of gated and vesicular transport. However, even this simple description shows the system’s irreducibly complex nature (Behe 1996).
Bacterial Flagellum
A motorboat uses a rotary propeller or motor to move the boat through water. Similarly, bacterial cells use a “rotary motor” called a flagellum to move the cells through liquid (Behe 1996). Figure 4.2 on page 13 is a picture of the bacterial flagellum, showing its parts that are similar to that of a man-made rotary motor.
This whip-like tail is made of a protein called flagellin. The flagellum is lodged in the cell membrane and attached to the rotor drive near the surface of the cell. The material that attaches the flagellum to the drive shaft is called hook protein. This protein works like a universal joint, which allows the flagellum and drive shaft to rotate. The motor that rotates the flagellum is located at the base of the flagellum where several rings are located (Behe 1996; Strobel 2004; undated University of California in Santa Barbara).
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Take NoteThe flagellum requires the coordination of 40 proteins. If one protein is missing, the flagellum will not function (Dembski 2003a).
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How did the bacterial flagellum come into existence? While evolutionists claim evolutionary processes are responsible for the flagellum’s existence, no scientist has ever presented an evolutionary model of the bacterial flagellum (Strobel 2004).
Evolutionists’ ArgumentsWhile scientists have failed to explain how evolution produced the flagellum, they have criticized Behe’s argument that the bacterial flagellum is irreducibly complex.
Ken Miller argues that the bacterial flagellum is not irreducibly complex for two reasons. Within the flagellum is a subsystem called Type III secretory system (TTSS). This system acts as a pump to move proteins to the outside of the cell. The function of TTSS is separate from the rotary propeller function of the flagellum. Evolutionists argue that the flagellum is not irreducibly complex because it evolved from TTSS. Remember, for an object to be irreducibly complex, it cannot have any precursors, i.e., any previous form of the object from which the more complex evolved (Dembski 2003b).
However, the existence of a subsystem within a functioning system is a poor argument for evolution. Dembski points out, “One might just as well say that because the motor of a motorcycle can be used as a blender, therefore the motor evolved into the motorcycle” (2003b, p 2).
Miller also claims that the flagellum is not irreducibly complex because TTSS can still transport proteins even if some proteins are missing. However, transporting proteins by the subsystem has little to do with the rotary propeller function of the flagellum. These are two separate functions. Moreover, if parts of the rotary system are missing, the propeller cannot function – regardless of whether or not proteins are missing. Therefore, the bacterial flagellum is irreducibly complex (Dembski 2003a).
Why does it matter whether or not an object or system is functional during its development? Evolutionists want us to believe that natural selection is how life began. However, if a system is not functioning, natural selection will not work. Since all parts must be in place at the same time in order for the bacterial flagellum to function, the flagellum could not have developed gradually over time (Behe 1996).
DNA
DNA is located in the nucleus of the cell and contains the information – the instructions - needed to make all the proteins that build our bodies. We depend on an alphabet that consists of 26 letters to form words that convey messages (Strobel 2004). Likewise, DNA’s instructions or messages are written with a special “alphabet” that consists of only four letters. Scientists have named these letters after the acids that form the DNA bases: A (adenine), G (guanine), T (thymine), and C (cytosine).
Each “letter” alone is meaningless, just as a single letter in the alphabet is meaningless. DNA’s letters must be in a specific order (called a sequence) in order to create instructions, just as the letters in this sentence must be in a specific arrangement in order to create a coherent message (Harris and Calvert 2003).
Therefore, DNA exhibits specified complexity because
Ø It is complex (made up of many components – letters)
Ø It is contingent (More than one combination of letters is possible.)
Ø It is specified (Follows a pattern called a sequence.).
Problem for EvolutionDNA and the information it contains must be present in order for life to begin (Strobel 2004). But how did DNA come into existence? Natural selection cannot explain the existence of DNA. Natural selection only works if organisms can duplicate themselves. In order to duplicate, organisms must have DNA. Therefore, if DNA is absent, natural selection cannot work. You have heard the question asked: “Which came first: the chicken or the egg?” Obviously, the chicken must exist first in order to reproduce to get the egg. In the same way, DNA must exist first in order for organisms to reproduce (Intelligent Design Basics undated).
Furthermore, the probability that DNA assembled itself in the first cell is 1 x 10 –190, which essentially equals zero (Harris and Calvert 2003).