Fall 2024
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By Carlos F. A. Pinkham
We have been warned that evolution is not teleological. Yet, when we look at the interplay of the physical, chemical, and biological processes that govern evolution, we discover that some outcomes are not permitted, while others are essential. Is that a form of teleology? We will explore this question by considering the way our cells function and the implications that has for body design. We might call this the phenomenon of narrowing options (1).
Selected Fundamentals of Biology
We will begin by exploring some fundamentals of the biology of our cells. The term “our cells” is necessary because microbial cells (what we generally call bacteria) in our body outnumber our own human cells ten to one. Microbial cells are prokaryotic or “simple” cells, while human cells are eukaryotic or “complex” cells. What follows is descriptive of complex cells and only, broadly speaking, of a few types of simple cells.
Our body consists of about 37.2 trillion complex cells (2) that fall into about 200 (3) to 500 (4) different types, depending upon whether the person doing the counting is a “lumper” or “splitter.” Of these different types, all but one follows the scheme I am about to describe. (The exception is the red blood cell (RBC), which accounts for 30% of all our cells—though even RBCs follow this scheme during their early life cycle.)
We have been warned that evolution is not teleological. Yet, when we look at the interplay of the physical, chemical, and biological processes that govern evolution, we discover that some outcomes are not permitted, while others are essential. Is that a form of teleology? We will explore this question by considering the way our cells function and the implications that has for body design. We might call this the phenomenon of narrowing options (1).
Selected Fundamentals of Biology
We will begin by exploring some fundamentals of the biology of our cells. The term “our cells” is necessary because microbial cells (what we generally call bacteria) in our body outnumber our own human cells ten to one. Microbial cells are prokaryotic or “simple” cells, while human cells are eukaryotic or “complex” cells. What follows is descriptive of complex cells and only, broadly speaking, of a few types of simple cells.
Our body consists of about 37.2 trillion complex cells (2) that fall into about 200 (3) to 500 (4) different types, depending upon whether the person doing the counting is a “lumper” or “splitter.” Of these different types, all but one follows the scheme I am about to describe. (The exception is the red blood cell (RBC), which accounts for 30% of all our cells—though even RBCs follow this scheme during their early life cycle.)
Almost all cells found in almost all animals and fungi follow this metabolic plan... |
The scheme involves tens of thousands of chemical reactions, known collectively as cellular metabolism, that are constantly going on in 70% of our cells. These reactions can be summarized with the plan shown in Figure 1, which illustrates what we could call the phenomenon of intricate simplicity (5). That is, Figure 1 accurately summarizes in a simple manner that which is intricate.
Figure 1. Cell Metabolism Simplified.
Thankfully, the details of these tens of thousands of chemical reactions need not concern us here. What’s important is that each unique set of them determines a unique cell function, and hence, for multicellular organisms like us, a cell type. Hundreds of thousands of different organic (carbon-containing) compounds are known. In living cells they fall into four functional-structural groups: carbohydrates, lipids, proteins, and nucleic acids. a striking example of intricate simplicity.
We will use the numbers in Figure 1* to guide our understanding of the diagram and see how the substances going into the cell (pink arrows) and those leaving the cell (blue arrows) drive the design of our body.
Cell function [1] depends upon a unique set of structural proteins [2] and enzymes [3]. (Enzymes are specialized proteins that catalyze, or speed up, chemical reactions.) The complicated process of the production of proteins is summarized by the terms protein synthesis or translation [4]. What follows applies to the general process of biosynthesis, be it of proteins or any of the other three groups of organic compounds.
Biosynthesis requires simpler molecules to build more complex molecules. These building blocks come from nutrients [5]. The process also needs energy to combine the building blocks into larger molecules through covalent bonds. This energy is provided by adenosine triphosphate [6] as it yields its bond energy when it breaks down into adenosine diphosphate (ADP) and phosphate (P) [8]. Water (H2O) [9] produced in the biosynthetic reaction is secreted from the cell.
The ATP consumed in biosynthesis is constantly replenished in a complicated process called cellular respiration [10]. Like all reactions, cellular respiration is not 100% efficient. Some of the energy [11], rather than being converted into ATP [6], is lost from the cell as heat [12].
The point of cellular respiration is to extract the energy stored in the chemical bonds of “chemical fuel” [13] to join ADP to phosphate and make ATP, in a reverse of the use of ATP in biosynthesis. Where does this fuel come from? From the same nutrients in food [5] that supply the building blocks. In the early steps of some biosynthetic reactions, waste metabolites [15] are produced. In cellular respiration, water [16] and carbon dioxide [17] are produced in addition to heat [12].
Although simple (prokaryotic) cells also use cellular respiration to form ATP, in most simple cells the form of cellular respiration used is much less efficient. For example, for every glucose molecule consumed by a typical simple cell, only 2 ATPs are produced. In our complex, eukaryotic cells, 30-32 ATPs per glucose are produced (6). Cellular respiration in our cells uses oxygen [18] to yield the extra ATPs from the fuel.
Now that we understand how our cells work, let’s examine how this process has resulted in the organ systems we find in our body. The body needs a digestive system to bring in nutrients [5] and water [14], and to reduce the former to small-enough molecules to get them into the cell. It needs a urinary system to remove the waste metabolites [15] and most of the excess water [9 & 16]. It needs a respiratory system to bring in the oxygen [18] and give off the other gas in this diagram, carbon dioxide [17], and some of the excess water [9 & 16]. It needs a cutaneous system to give off the remaining excess water [9 & 16] and heat [12]. And it needs a circulatory system to bring the small molecules from where they enter the circulation to all the cells: nutrients [5] and water molecules [14] from the digestive system, and oxygen [18] from the respiratory system—and then to carry the waste metabolites [15], excess water [9 & 16], and carbon dioxide [17] from the cells to where they are expelled from the body.
Almost all cells found in almost all animals and fungi follow this metabolic plan, as do the cells in non-photosynthesizing plants. Even photosynthesizing plant cells use it in the dark. If an organism’s source of nutrients and building blocks are readily available without moving from place to place, as is the case for plants and fungi, it needs no other organ system—but if it is not, then a skeleto-muscular system must exist to move the organism from an area of depleted fuels to an area with more suitable resources, a nervous system to coordinate all this activity in the moment, and an endocrine system to coordinate it over time.
In other words, the body is a slave to the cell. Does that suggest that evolution must have had this endpoint in mind when the first complex cell came into existence? Undoubtedly not. But does it suggest that an infinitely complex mind behind evolution planned for this endpoint? I suspect so.
*The numbers in Figure 1 are referred to in the text within brackets (such as [1].) Number is parentheses refer to references.
References
1. Pinkham, Carlos F.A. “Evolution is not the Enemy; Intelligent Design is not the Solution.” Presented at the Oxford Round Table on "Science and Faith: The Great Matter." July 26, 2006.
2. “Human Cell Atlas.”
3. Kramer, Daniel. “Discovering new cell types one at a time.” Bio 2.0 – Dissecting the next revolution in biology. June 2, 2015.
4. Malesu, Vijay Kumar, “Mapping the human body one cell at a time: New study reveals the intricate relationship between cell size and count.” News Medical/Life Sciences. Sept 19, 2023. Link
5. Pinkham, Carlos F.A. "Evolution is not the Enemy; Intelligent Design is not the Solution." Presented at the Oxford Round Table on “Science and Faith: The Great Matter,” July 26, 2006.
6. “7.13: Oxidative Phosphorylation - ATP Yield.” in General Biology. Boundless. Link
Carlos Pinkham received a PhD in evolution from University of Illinois, Urbana Champaign, in 1971. He entered the Army's environmental program at its inception and retired as Colonel in 2003. In 1982 he joined the Biology Department of Norwich University, Northfield, VT, as a Visiting Professor, where he taught environmental biology and human anatomy and physiology. In 2009 he retired as Professor Emeritus of Biology. He is the author of The Trouble with the Trinity, A Layman-to-Layman Study of the Biblical Evidence for the Triune Nature of God. (Covenant, 2019). He is vice-president of the Affiliation of Christian Biologists.
Figure 1. Cell Metabolism Simplified.
Thankfully, the details of these tens of thousands of chemical reactions need not concern us here. What’s important is that each unique set of them determines a unique cell function, and hence, for multicellular organisms like us, a cell type. Hundreds of thousands of different organic (carbon-containing) compounds are known. In living cells they fall into four functional-structural groups: carbohydrates, lipids, proteins, and nucleic acids. a striking example of intricate simplicity.
We will use the numbers in Figure 1* to guide our understanding of the diagram and see how the substances going into the cell (pink arrows) and those leaving the cell (blue arrows) drive the design of our body.
Cell function [1] depends upon a unique set of structural proteins [2] and enzymes [3]. (Enzymes are specialized proteins that catalyze, or speed up, chemical reactions.) The complicated process of the production of proteins is summarized by the terms protein synthesis or translation [4]. What follows applies to the general process of biosynthesis, be it of proteins or any of the other three groups of organic compounds.
Biosynthesis requires simpler molecules to build more complex molecules. These building blocks come from nutrients [5]. The process also needs energy to combine the building blocks into larger molecules through covalent bonds. This energy is provided by adenosine triphosphate [6] as it yields its bond energy when it breaks down into adenosine diphosphate (ADP) and phosphate (P) [8]. Water (H2O) [9] produced in the biosynthetic reaction is secreted from the cell.
The ATP consumed in biosynthesis is constantly replenished in a complicated process called cellular respiration [10]. Like all reactions, cellular respiration is not 100% efficient. Some of the energy [11], rather than being converted into ATP [6], is lost from the cell as heat [12].
The point of cellular respiration is to extract the energy stored in the chemical bonds of “chemical fuel” [13] to join ADP to phosphate and make ATP, in a reverse of the use of ATP in biosynthesis. Where does this fuel come from? From the same nutrients in food [5] that supply the building blocks. In the early steps of some biosynthetic reactions, waste metabolites [15] are produced. In cellular respiration, water [16] and carbon dioxide [17] are produced in addition to heat [12].
Although simple (prokaryotic) cells also use cellular respiration to form ATP, in most simple cells the form of cellular respiration used is much less efficient. For example, for every glucose molecule consumed by a typical simple cell, only 2 ATPs are produced. In our complex, eukaryotic cells, 30-32 ATPs per glucose are produced (6). Cellular respiration in our cells uses oxygen [18] to yield the extra ATPs from the fuel.
Now that we understand how our cells work, let’s examine how this process has resulted in the organ systems we find in our body. The body needs a digestive system to bring in nutrients [5] and water [14], and to reduce the former to small-enough molecules to get them into the cell. It needs a urinary system to remove the waste metabolites [15] and most of the excess water [9 & 16]. It needs a respiratory system to bring in the oxygen [18] and give off the other gas in this diagram, carbon dioxide [17], and some of the excess water [9 & 16]. It needs a cutaneous system to give off the remaining excess water [9 & 16] and heat [12]. And it needs a circulatory system to bring the small molecules from where they enter the circulation to all the cells: nutrients [5] and water molecules [14] from the digestive system, and oxygen [18] from the respiratory system—and then to carry the waste metabolites [15], excess water [9 & 16], and carbon dioxide [17] from the cells to where they are expelled from the body.
Almost all cells found in almost all animals and fungi follow this metabolic plan, as do the cells in non-photosynthesizing plants. Even photosynthesizing plant cells use it in the dark. If an organism’s source of nutrients and building blocks are readily available without moving from place to place, as is the case for plants and fungi, it needs no other organ system—but if it is not, then a skeleto-muscular system must exist to move the organism from an area of depleted fuels to an area with more suitable resources, a nervous system to coordinate all this activity in the moment, and an endocrine system to coordinate it over time.
In other words, the body is a slave to the cell. Does that suggest that evolution must have had this endpoint in mind when the first complex cell came into existence? Undoubtedly not. But does it suggest that an infinitely complex mind behind evolution planned for this endpoint? I suspect so.
*The numbers in Figure 1 are referred to in the text within brackets (such as [1].) Number is parentheses refer to references.
References
1. Pinkham, Carlos F.A. “Evolution is not the Enemy; Intelligent Design is not the Solution.” Presented at the Oxford Round Table on "Science and Faith: The Great Matter." July 26, 2006.
2. “Human Cell Atlas.”
3. Kramer, Daniel. “Discovering new cell types one at a time.” Bio 2.0 – Dissecting the next revolution in biology. June 2, 2015.
4. Malesu, Vijay Kumar, “Mapping the human body one cell at a time: New study reveals the intricate relationship between cell size and count.” News Medical/Life Sciences. Sept 19, 2023. Link
5. Pinkham, Carlos F.A. "Evolution is not the Enemy; Intelligent Design is not the Solution." Presented at the Oxford Round Table on “Science and Faith: The Great Matter,” July 26, 2006.
6. “7.13: Oxidative Phosphorylation - ATP Yield.” in General Biology. Boundless. Link
Carlos Pinkham received a PhD in evolution from University of Illinois, Urbana Champaign, in 1971. He entered the Army's environmental program at its inception and retired as Colonel in 2003. In 1982 he joined the Biology Department of Norwich University, Northfield, VT, as a Visiting Professor, where he taught environmental biology and human anatomy and physiology. In 2009 he retired as Professor Emeritus of Biology. He is the author of The Trouble with the Trinity, A Layman-to-Layman Study of the Biblical Evidence for the Triune Nature of God. (Covenant, 2019). He is vice-president of the Affiliation of Christian Biologists.