26. Cells—The Building Blocks of Life
“And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.” Gen 2:7 (NASB)
In Origin of Species, Charles Darwin wrote, “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.” In the 19th century it was supposed that a cell was the smallest component of an organ. Neither Darwin nor biologists of his time could have guessed at the true complexity of a living cell as we know about it today. The real question is less about total complexity and more about the possibility of development of complex systems from simple components.
A cell consists of many components, but no component is as uniquely complex as DNA. The nucleus of a cell contains DNA, the library of blueprints needed to produce any part of any cell in the organism. Stem cells are highly prized because they contain a complete DNA library—most other cells contain only the partial DNA required for specific functions. DNA is three-dimensional structure built of pairs of acids, linked by sugars, arranged in strings to form sections called chromosomes. Human DNA consists of 46 chromosomes. DNA of even the most basic organism is highly complex. There are at least five million unique sets of DNA in existence because there are that many unique life forms.
A living cell holds thousands of complex enzymes. Each enzyme comes into being in response to a gene (a strand of DNA). The information in each strand of DNA must be at least as complex as the enzyme it controls. A medium protein includes about 300 amino acids. The DNA gene controlling this cell has about 1000 nucleotides in its chain. There are four types of nucleotides in a chain, which means there is about 41000 or 10600 possible combinations of data. To put this into some sort of meaningful perspective, suppose each word in a book represents one of those pieces of data. If you assume there’s an average of 500 words per page and 500 pages per book, then assume 10,000 copies each of 10,000,000 books are published each year. Assume books have published at this rate for a period of 4000 years. The total number of meaningful words ever published would amount to 1066. The information in a single DNA molecule is therefore 10534 times the number of words ever published assuming books were published since before the time of Moses at today’s pace.
For a cell to reproduce you must have the original cell and the controlling gene (portion of DNA library related to the cell) containing the information necessary for duplication. The gene is embedded in the cell, therefore you must not only have the complex cell but the cell must contain all the genetic information to self-replicate. Which came first, the blueprint for the cell or the cell needed to house the blueprint?
In most cells RNA acts like the librarian for the DNA library. RNA copies the necessary elements of DNA and checks them out to other parts of the cell. In addition to information transmission, a power supply is needed to run things. The power plant in most animal organisms is called the mitochondria and in plants it is called the chloroplast. The power plant machinery is the most substantial difference between animal and plant cells. A factory called the ribosome takes information from the RNA messenger and energy from the mitochondria (or chloroplast) power plant to manufacture new or replacement proteins, DNA, or another ribosome. After a ribosome factory cranks out some new component, the gogli warehouse stores and functions as distribution center for the cell. Endoplasmic reticulum is the trucking company used to transport ribosome’s produce from the gogli warehouse to the final destination. Trucks need roads on which to carry their goods. This is where the centrosome highway network comes in. From time to time a parking lot is required for temporary storage while the trucking company negotiates traffic. Vacuoles function like parking lots here and there along the centrosome highways. Integrated into this system are fuel consumption and waste disposal mechanisms. Lysomes digest food, bacteria, and other cell parts that are worn out to create the raw fuel used by the power plant and other working components in the cell. Peroxisomes process waste, sometimes by causing a damaged cell to self-destruct for the good of the organism. A basic cell houses all of these common parts, yet is only 1 to 100 microns in diameter.
Darwinian Evolution requires naturally increasing complexity. The basic idea is that two very small function components can be put together to form a higher level functional device. Two higher level devices can be combined to make an even more complex machine. There are two major difficulties with this basic principle at the heart of Darwinian Evolution. The first, entropy, was covered largely in a previous chapter. Entropy is the principle which states order tends to decrease unless useful energy (or information) is added from an external source. With regard to biological systems, a complimentary principle called irreducible complexity is the other major problem.
The principle of irreducible complexity is that some things cannot be made any simpler without loosing usefulness. For example, a basic mousetrap might require five components to function. If any of those parts are missing, the trap will not work. Placing the parts in a box and shaking the box almost certainly is not going to result in a working mousetrap no matter how long you shake the box. Any four of the parts, even if put together properly, will not make a working trap. All five parts must be present and must be properly assembled by an intelligent builder. Additional parts could be added to enhance the basic trap, but no parts can be removed or it ceases to be a trap. The five-part trap is an irreducibly complex machine.
There are many examples of irreducible complexity in biology, from eyes to bacteria flagellum. Human eyes are more complex than insect eyes, yet the most basic eye of the most basic animal cannot be simplified even slightly without the loss of vision. A blind eye serves no evolutionary value because, according to Darwin’s application of natural selection, the blind eye is not useful and would be rejected. Evolutionary theory supposes increasing complexity through natural selection, but it cannot explain the original organization of very specialized components needed to receive, perceive, and transmit visual information. On the cellular, consider bacteria flagellum. A single flagellum is essentially a rotary propeller. It operates at 10,000 RPM and includes a universal joint, bushings, bearings, and the whip propeller. If even one protein were missing, of the wrong type, or in the wrong position, the flagellum would be useless.
As illustrated in this chapter, living things are made up of cells. Cells contain many small and complicated parts including the instructions and mechanisms needed to reproduce. When examined closely, many components of cells serve no useful purpose unless they are complete. A cell cannot reproduce unless it contains both the complete replicating components and the DNA instructions used by the replicating components. In this basic sense any sort of living cell is, by its nature, irreducibly complex. Many organs, such as the highly complex eye, cannot be significantly simplified without being useless. Cold rational logic suggests that the evolutionary notion that irreducibly complex organs, cells, or even specialized and necessary proteins could be the product of beneficial chance mutation is utterly untenable. The alternative, no matter how unpleasant to a being who thinks himself (or herself) to be no more than their material biology, must be rejected only on the basis of emotional commitment to denial of the truth. It is the desire of mankind to rebel against God and make himself (or herself) their own master. If the alternative is allowed, that an intelligent unseen supernatural Creator might actually exist. If there is a Creator, then perhaps there is also a biblical heaven, hell, Jesus Christ, and Holy Spirit. Moral absolutes—holiness and sin—would then have to be faced and dealt with.
Related Topics: Creation