Control Loops in Humans and Nature | The Institute for Creation Research
Control Loops in Humans and Nature
Ever had a blood test? Along with a value measured, there are also the normal max/min limits for that value. This implies that the body normally controls that quantity between those limits. How does it do that?

It measures the value and produces more or less of that quantity based on the value measured. This is called a control loop. There are hundreds of thousands, perhaps millions, of control loops in the human body.

To understand the components of a control loop, let us look at a familiar example: controlling the temperature in your home. A thermostat measures the room temperature. The logic is to turn the power to the heater on if the room temperature is below a set temperature, T1. When the temperature rises above a second set temperature, T2, the thermostat turns the power off.1 This control loop is shown in Figure 1. It is called a loop because the heater output, the heat, is looped back through the room to the thermostat (called feedback) to provide control.

In summer, when the ambient temperature is high, the heater remains off. Note that all the components of the heating system are still there—the thermostat, the heater, and the power to run it. The heating system does not “devolve” in summer, it is just quiescent. In winter, when temperatures are low again, the heat comes back on. The heating system did not re-evolve. It was there all the time, just latent!

Figure 1. A Typical Thermostat Control Loop Used for Heating Systems.2
 
The above system is an example of continuous environmental tracking (CET) or monitoring. The thermostat is continuously monitoring the temperature, i.e. the environment, and is ready to respond when needed.

We find similar systems in the human body. Some examples are sweating when hot and shivering when cold. These reactions occur only when needed, as in the heating control loop above, and are otherwise latent.

Biological control loops function by turning hormones and/or genes on and off, like the power example above. Similar to the thermostat in summer, some can be latent for extended periods. For example, blood doesn’t clot (fortunately) until we have a cut. Then, many mechanisms turn on to stop the bleeding. They turn off when the bleeding is stopped. In this example, there are loops within loops (called nested loops) that can provide coarse and fine control. The control loops are always there, operating when needed, similar to the heater loop above.

Control loops governed by genes may be off for long periods of time, even for a lifetime, by epigenetics, as in adaptation. The controlling genes remain (every cell has the full genome) but just aren’t active or expressed (like turning off the power). A chemical binds to specified DNA regions turning genes off or on, disabling the control loop. On a micro-scale, nerve cells and muscle cells have the same DNA, but because different genes are turned on/off, they have entirely different attributes and functions. The same genome is still there, just adapted. On a macro-scale, epigenetic changes can be inherited and help people adapt to their environments.

In conclusion, functional changes are easily explained by biological control loops continuously monitoring their environment. They may be active, latent (ready when needed), or turned off. They explain biologic functioning and adaption. Evolution/devolution doesn’t make sense.

Notes
1. When a control loop has only two states—power fully on or off—it’s called a bang-bang control loop. This differs from the more common proportional control loop, or servo loop.
2. In mechanical thermostats, the detection and logic are combined.

*Dr. Siebert earned his Ph.D. in equations of quantum mechanics from the Polytechnic Institute of New York University. He is a freelance contributor to ICR’s Creation Science Update, has worked 40 years in electro-optics, and held numerous patents.
The Latest
CREATION.LIVE PODCAST
Beauty for Beauty's Sake! | Creation.Live Podcast: Episode 17
Beauty is in the eye of the beholder, right? Or is beauty an objective standard? Where do our ideas of beauty even come from?   Hosts...

NEWS
Fire Sensory Capabilities of the Venus Flytrap
Fascinating discoveries have been made regarding the amazing Venus flytrap (Dionaea muscipula).1 For example, all parts of this amazing plant...

CREATION PODCAST
What Really Swallowed Jonah? | The Creation Podcast: Episode...
The book of Jonah contains the historical account of the prophet Jonah. In verse 17 of chapter 1, the text states that the Lord prepared a great...

NEWS
More Flood Evidence
Paleontologists recently discovered the partial fossils of two new species of dinosaur just outside of Casablanca. As stated in a Science Direct article,...

NEWS
New York Times Editorial: Big Bang Unraveling?
Two physicists have suggested in a recent New York Times guest editorial that Big Bang cosmology ‘may be starting to unravel.’1...

NEWS
Your Functional ''Yolk Sac''
For decades, evolutionists pointed to dozens of ‘useless artifacts’ of the human body to make their questionable case for evolution. But...

NEWS
The Beauty of Creation: Created for God’s Own Glory
Have you ever wondered why a sunset on a beach is captivating, snowcapped mountains are breathtaking, and a valley filled with wildflowers is enchanting? Scripture,...

CREATION PODCAST
Devastating, Dangerous, and Deadly Bacteria? | The Creation Podcast:...
Bacteria are everywhere! While we can't see them with the naked eye, these little critters are everywhere, even in and on your body! Some of...

NEWS
Pre-Flood Reptile Fossil Discovered With Baleen
Baleen whales (suborder Mysticeti) are amazing filter-feeding mammals of the sea. They belong to a group called the Cetacea. Evolutionists suggest they...

NEWS
September 2023 ICR Wallpaper
"If you walk in My statutes and keep My commandments, and perform them, then I will give you rain in its season, the land shall yield its produce, and...