Creation Questions

Tag: creation

  • Human Eyes – Optimized Design

    Human Eyes – Optimized Design

    Is the human eye poorly designed? Or is it optimal?

    If you ask most proponents of modern evolutionary theory, you will often hear that the eye is a pinnacle of unfortunate evolutionary history and dysteleology.

    There are three major arguments that are used in defending this view:

    The human eye:

    1. is inverted (retina) and wired backwards
    2. has a blind spot due to nerve exit
    3. Is fragile due to retinal detachment

    #1 THE HUMAN EYE IS INVERTED

    The single most famous critique is, of course, the backward wiring of the retina. An optimal sensor should use its entire surface area for data collection, right? The vertebrate eye requires obstruction of the eye-path by axons and capillaries before it hits the photoreceptors.

    Take the cephalopod eye: it has an everted retina, the photo receptors face the light and the nerves are behind them meaning there is no need for a blind spot. The human reversed wiring represents a mere local (rather than global) maximum where the eye could only optimize so far due to its evolutionary history.

    Yet, this argument misses non-negotiable constraints. There is a metabolic necessity for the human eye which doesn’t exist in the squid or octopus.

    Photoreceptors (the rods and cones) have the highest metabolic rate of any cell in the body. They generate extreme heat and oxygen levels and undergo constant repair from constant reaction from photons. The energy demand is massive. This is an issue of thermoregulation, not just optics.

    The reason this is important is because the vertebrate eye is structured with an inverted retina precisely for the survival and longevity of these high-energy photoreceptors. These cells require massive, continuous nutrient and oxygen delivery, and rapid waste removal.

    The current inverted orientation is the only geometric configuration that allows the photoreceptors to be placed in direct contact with the Retinal Pigment Epithelium (RPE) and the choroid. The choroid, a vascular layer, serves as the cooling system and high-volume nutrient source, similar to a cooling unit directly attached to a high-performance processor.

    If the retina were wired forward, the neural cabling would form a barrier, blocking the connection between the photoreceptors and the choroid. This would inevitably lead to nutrient starvation and thermal damage. Not only that, but human photoreceptors constantly shed toxic outer segments due to damage, which must be removed via phagocytosis by the RPE. The eye needs the tips of the photoreceptors to be physically embedded in the RPE. 

    If the nerve fibers were placed in front they would form a barrier, preventing waste removal. This specific geometry is a geometric imperative for long-term molecular recycling and allows for eyes that last for 80+ years on the regular.

    Critics often insist however that even given the neural and capillary layers being necessary for metabolism, it is still a poor design because they block or scatter incoming light. 

    Yet, research has demonstrated that Müller glial cells span the thickness of the retina and act as essentially living fiber-optic cables. These cells possess a higher refractive index than the surrounding tissue, which gives them the capability to channel light directly to the cones with minimal scattering.

    So this criticism actually goes from being a poor design choice into an awesome low-pass filter which improves the signal-to-noise ratio and visual acuity of the human eye.

    But wait, there’s more! The neural layers contain yellow pigments (lutein and zeaxanthin) which absorb excess blue and ultraviolet light that is highly phototoxic! This layer is basically a forcefield against harmful rays (photo-oxidative damage) which extends the lifespan of these super delicate sensors.

    #2 THE HUMAN EYE HAS A BLIND SPOT

    However, the skeptics will still push back (which leads to point number 2): But surely a good design would not include a blind spot where the optic nerve runs through! And indeed this point is a fairly powerful one at a glance. But on further inspection, we see that this exit point, where literally millions of nerve fibers bundle together to pass the photoreceptors, is an example of optimized routing and not a critical flaw of any kind.

    This is true for many reasons. For one, by having the nerves bundle into this reinforced exit point, in this way, maximized the structural robustness of the remaining retina. Basically, if it were not this way, and the nerve fibers exited individually or even in small clusters across the retina, it would radically lower the integrity of the whole design. It would make the retina prone to tearing during rapid eye movements (saccades). In other words, we wouldn’t be getting much REM sleep! That, but also, we’d be missing out on most looking around of any kind.

    I’d say, even if that was the only advantage, the loss of a tiny fraction of our visual field is worth the trade-off.

    Second, and this is important, the blind spot is functionally irrelevant. What do I mean by that? I mean that humans were designed with two eyes for the purpose of seeing depth-of-field, i.e., understanding where things are in space. You can’t do that with one eye, so that’s not an option. With two eyes, the functional retina of the left eye covers the blind spot of the right eye, and vice versa. There is no problem in this design if both the vision is covered and depth-of-field are covered 100% accurately: which they are.

    Third, the optic disc is also used for integrated signal processing, containing melanopsin-driven cells that calibrate brightness perception for the entire eye, using the exit cable as a sensor probe. That means that the nerves also detect brightness and run the logistics in a localized region which is incredibly efficient.

    #3 THE HUMAN EYE IS VULNERABLE

    That is, the vulnerability specifically refers to retinal detachment. That is when the neural retina separates from the RPE. Why does this happen? It is a consequence of the retina being held loosely against the choroid, largely by hydrostatic pressure. Critics call this a failure point. Wouldn’t a good design be one where the RPE is solidly in place, especially if it needs to be connected to the retina? Well… no, not remotely.

    The RPE must actively transport massive amounts of fluid (approximately 10 liters per day) out of the subretinal space to the choroid to prevent edema (swelling) and maintain clear vision. A mechanically fused retina would impede this rapid fluid transport and waste exchange. Basically, the critics offer a solution which is really a non-solution. There is no possible way the eye could function at all by the means they suggest as the alternative “superior” version.

    So, what have we learned?

    The human eye is not a collection of accidents, but a masterpiece of constrained optimization. When the entire system (eye and brain) is evaluated, the result is astonishing performance. The eye achieves resolution at the diffraction limit (the theoretical physical limit imposed by the wave nature of light!) at the fovea, meaning it is hitting the maximum acuity possible for an aperture of its size.

    The arguments that the eye is “sub-optimal” often rely on comparing it to the structurally simpler cephalopod eye. Yet, cephalopod eyes lack trichromatic vision (they don’t see color like we do), have lower acuity (on the scale of hundreds of times worse clarity), and only function for a lifespan of 1–2 years (whereas the human eye must self-repair and maintain high performance for eight decades). The eye’s complexity—the Müller cells, the foveal pit, and the inverted architecture—are the necessary subsystems required to achieve this maximal performance within the constraints of vertebrate biology and physics.

    That’s not even getting to things like mitochondrial microlens in our cells which are essential for processing light. Recent research suggests that mitochondria in cone photoreceptors may actually function as micro-lenses to concentrate light, adding another layer of optical optimization. Optimization which would need to be there, perhaps a lot earlier than even the reversed lens structure.

    The fact that the eye is so optimal still remains, despite the critics best attempts at thwarting it. Therefore, the question remains, how could something so optimized evolve by random chance mutation, as well as so early and often in the history of biota?

  • An Argument for Agent Causation in the Origin of DNA’s Information

    An Argument for Agent Causation in the Origin of DNA’s Information

    NOTE: This is a design argument inspired by Stephen Meyer‘s design argument from DNA. Importantly, specified complexity is changed for semiotic code (which I feel is more precise) and intelligent design is changed to agent causation (which is more preferencial).

    This argument posits that the very nature of the information encoded in DNA, specifically its structure as a semiotic code, necessitates an intelligent cause in its origin. The argument proceeds by establishing two key premises: first, that semiotic codes inherently require intelligent (agent) causation for their creation, and second, that DNA functions as a semiotic code.

    Premise 1: The Creation of a Semiotic Code Requires Agent Causation (Intelligence)

    A semiotic code is a system designed for conveying meaning through the use of signs. At its core, a semiotic code establishes a relationship between a signifier (the form the sign takes, e.g., a word, a symbol, a sequence) and a signified (the concept or meaning represented). Crucially, in a semiotic code, this relationship is arbitrary or conventional, not based on inherent physical or chemical causation between the signifier and the signified. This requires an interpretive framework – a set of rules or a system – that is independent of the physical properties of the signifier itself, providing the means to encode and decode the meaning. The meaning resides not in the physical signal, but in its interpretation according to the established code.

    Consider examples like human language, musical notation, or traffic signals. The sound “stop” or the sequence of letters S-T-O-P has no inherent physical property that forces a vehicle to cease motion. A red light does not chemically or physically cause a car to stop; it is a conventionally assigned symbol that, within a shared interpretive framework (traffic laws and driver understanding), signifies a command to stop. This is distinct from a natural sign, such as smoke indicating fire. In this case, the relationship between smoke and fire is one of direct, necessary physical causation (combustion produces smoke). While an observer can interpret smoke as a sign of fire, the connection itself is a product of natural laws, existing independently of any imposed code or interpretive framework.

    The capacity to create and utilize a system where arbitrary symbols reliably and purposefully convey specific meanings requires more than just physical processes. It requires the ability to:

    Conceive of a goal: To transfer specific information or instruct an action.

    Establish arbitrary conventions: To assign meaning to a form (signifier) where no inherent physical link exists to the meaning (signified).

    Design an interpretive framework: To build or establish a system of rules or machinery that can reliably encode and decode these arbitrary relationships.

    Implement this system for goal-directed action: To use the code and framework to achieve the initial goal of information transfer and subsequent action based on that information.

    This capacity to establish arbitrary, rule-governed relationships for the purpose of communication and control is what we define as intelligence in this context. The creation of a semiotic code is an act of imposing abstract order and meaning onto physical elements according to a plan or intention. Such an act requires agent causation – causation originating from an entity capable of intentionality, symbolic representation, and the design of systems that operate based on abstract rules, rather than solely from the necessary interactions of physical forces (event causation).

    Purely natural, undirected physical processes can produce complex patterns and structures driven by energy gradients, chemical affinities, or physical laws (like crystal formation, which is a direct physical consequence of electrochemical forces and molecular structure, lacking arbitrary convention, an independent interpretive framework, or symbolic representation). However, they lack the capacity to establish arbitrary conventions where the link between form and meaning is not physically determined, nor can they spontaneously generate an interpretive framework that operates based on such non-physical rules for goal-directed purposes. Therefore, the existence of a semiotic code, characterized by arbitrary signifier-signified links and an independent interpretive framework for goal-directed information transfer, provides compelling evidence for the involvement of intelligence in its origin.

    Premise 2: DNA Functions as a Semiotic Code

    The genetic code within DNA exhibits the key characteristics of a semiotic code as defined above. Sequences of nucleotides (specifically, codons on mRNA) act as signifiers. The signifieds are specific amino acids, which are the building blocks of proteins.

    Crucially, the relationship between a codon sequence and the amino acid it specifies is not one of direct chemical causation. A codon (e.g., AUG) does not chemically synthesize or form the amino acid methionine through a direct physical reaction dictated by the codon’s molecular structure alone. Amino acid synthesis occurs through entirely separate biochemical pathways involving dedicated enzymes.

    Instead, the codon serves as a symbolic signal that is interpreted by the complex cellular machinery of protein synthesis – the ribosomes, transfer RNAs (tRNAs), and aminoacyl-tRNA synthetases. This machinery constitutes the interpretive framework.

    Here’s how it functions as a semiotic framework:

    • Arbitrary/Conventional Relationship: The specific assignment of a codon triplet to a particular amino acid is largely a matter of convention. While there might be some historical or biochemical reasons that biased the code’s evolution, the evidence from synthetic biology, where scientists have successfully engineered bacteria with different codon-amino acid assignments, demonstrates that the relationship is not one of necessary physical linkage but of an established (and in this case, artificially modified) rule or convention. Different codon assignments could work, but the system functions because the cellular machinery reliably follows the established rules of the genetic code.
    • Independent Interpretive Framework: The translation machinery (ribosome, tRNAs, synthetases) is a complex system that reads the mRNA sequence (signifier) and brings the correct amino acid (signified) to the growing protein chain, according to the rules encoded in the structure and function of the tRNAs and synthetases. The meaning (“add this amino acid now”) is not inherent in the chemical properties of the codon itself but resides in how the interpretive machinery is designed to react to that codon. This machinery operates independently of direct physical causation by the codon itself to create the amino acid; it interprets the codon as an instruction within the system’s logic.
    • Symbolic Representation: The codon stands for an amino acid; it is a symbol representing a unit of meaning within the context of protein assembly. The physical form (nucleotide sequence) is distinct from the meaning it conveys (which amino acid to add). This is analogous to the word “cat” representing a feline creature – the sound or letters don’t physically embody the cat but symbolize the concept.

    Therefore, DNA, specifically the genetic code and the translation system that interprets it, functions as a sophisticated semiotic code. It involves arbitrary relationships between signifiers (codons) and signifieds (amino acids), mediated by an independent interpretive framework (translation machinery) for the purpose of constructing functional proteins (goal-directed information transfer).

    Conclusion: Therefore, DNA Requires Agent Causation in its Origin

    Based on the premises established:

    1. The creation of a semiotic code, characterized by arbitrary conventions, an independent interpretive framework, and symbolic representation for goal-directed information transfer, requires the specific capacities associated with intelligence and agent causation (intentionality, abstraction, rule-creation, system design).
    2. DNA, through the genetic code and its translation machinery, functions as a semiotic code exhibiting these very characteristics.

    It logically follows that the origin of DNA’s semiotic structure requires agent causation. The arbitrary nature of the code assignments and the existence of a complex system specifically designed to read and act upon these arbitrary rules, independent of direct physical necessity between codon and amino acid, are hallmarks of intelligent design, not the expected outcomes of undirected physical or chemical processes.

    Addressing Potential Objections:

    • Evolution and Randomness: While natural selection can act on variations in existing biological systems, it requires a self-replicating system with heredity – which presupposes the existence of a functional coding and translation system. Natural selection is a filter and modifier of existing information; it is not a mechanism for generating a semiotic code from scratch. Randomness, by definition, lacks the capacity to produce the specified, functional, arbitrary conventions and the integrated interpretive machinery characteristic of a semiotic code. The challenge is not just sequence generation, but the origin of the meaningful, rule-governed relationship between sequences and outcomes, and the system that enforces these rules.
    • “Frozen Accident” and Abiogenesis Challenges: Hypotheses about abiogenesis and early life (like the RNA world) face significant hurdles in explaining the origin of this integrated semiotic system. The translation machinery is a highly complex and interdependent system (a “chicken-and-and egg” problem where codons require tRNAs and synthetases to be read, but tRNAs and synthetases are themselves encoded by and produced through this same system). The origin of the arbitrary codon-amino acid assignments and the simultaneous emergence of the complex machinery to interpret them presents a significant challenge for gradual, undirected assembly driven solely by chemical or physical affinities.
    • Biochemical Processes vs. Interpretation: The argument does not claim that a ribosome is a conscious entity “interpreting” in the human sense. Instead, it argues that the system it is part of (the genetic code and translation machinery) functions as an interpretive framework because it reads symbols (codons) and acts according to established, arbitrary rules (the genetic code’s assignments) to produce a specific output (amino acid sequence), where this relationship is not based on direct physical necessity but on a mapping established by the code’s design. This rule-governed, symbolic mapping, independent of physical causation between symbol and meaning, is the defining feature of a semiotic code requiring an intelligence to establish the rules and the system.
    • God-of-the-Gaps: This argument is not based on mere ignorance of a natural explanation. It is a positive argument based on the nature of the phenomenon itself. Semiotic codes, wherever their origin is understood (human language, computer code), are the products of intelligent activity involving the creation and implementation of arbitrary conventions and interpretive systems for goal-directed communication. The argument posits that DNA exhibits these defining characteristics and therefore infers a similar type of cause in its origin, based on a uniformity of experience regarding the necessary preconditions for semiotic systems.

    In conclusion, the sophisticated, arbitrary, and rule-governed nature of the genetic code and its associated translation machinery point to it being a semiotic system. Based on the inherent requirements for creating such a system—namely, the capacities for intentionality, symbolic representation, rule-creation, and system design—the origin of DNA’s information is best explained by the action of an intelligent agent.