July 2, 2013 | David F. Coppedge

More Wonders Going On Inside You

Since we all live in a body, we should all feel intrigued with what goes in under our skin.  There are more wonders than science can ever fully know.  Here are a few recent examples.

Looking and recognizing:  Why do secure websites ask you to identify words with curvy, speckled letters before letting you in?  The reason for CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is that humans are far superior in recognizing misshapen words than computers.  No robot can come close, Science Daily said:

It seems easy to us — the human brain just does it. But the apparent simplicity of this task is an illusion. The task is actually so complex, no one has been able to write computer code that translates these distorted letters the same way that neural networks can. That’s why this test, called a CAPTCHA, is used to distinguish a human response from computer bots that try to steal sensitive information.

The article tells how scientists at Salk Institute are taking wee steps at understanding the eye-brain system’s skill.  Some day, robot engineers may master it, but for now, it sets us apart.

Nice fat:  Fat gets a bad rap, but it wraps us in a layer that can not only feel temperature, but do something about it.  A new paper in PNAS describes how fat cells “directly sense temperature to activate thermogenesis” – the creation of heat, even without shivering.  To do this, fat cells must be smart enough to do two things:  respond to environmental cues, and know how to activate signal pathways that turn up the heat.  The authors say, “These findings provide an unusual insight into the role of adipose tissues in thermoregulation, as well as an alternative way to target nonshivering thermogenesis for treatment of obesity and metabolic diseases.”

Shape shifters:  Many organs in the body are lined with epithelial cells, cells that line up form protective walls.  But they’re not just walls that are built and forgotten.  Like fat cells, they respond, too, in a kind of fluid motion involving death and regeneration of individual “bricks” in the wall.  Two French scientists wrote in Science Magazine about “Mechanics of Epithelial Tissue Homeostasis and Morphogenesis,” describing how wall-building is an ongoing, purpose-driven process:

Epithelia are robust tissues that support the structure of embryos and organs and serve as effective barriers against pathogens. Epithelia also chemically separate different physiological environments. These vital functions require tight association between cells through the assembly of junctions that mechanically stabilize the tissue. Remarkably, epithelia are also dynamic and can display a fluid behavior. Cells continuously die or divide, thereby allowing functional tissue homeostasis. Epithelial cells can change shape or intercalate as tissues deform during morphogenesis.

The authors did not mention evolution.  Instead, they stated that control involves multiple levels of organization – in human experience, a hallmark of intelligent design.  Without using the ID phrase, here’s how they described the outlook for science:

We are entering an exciting time when interdisciplinary research enables us to understand the fundamental properties of tissue functional homeostasis and morphogenesis by considering the interplay between biochemical and mechanical signals across different scales of organization.

A ubiquitous code:  The protein ubiquitin, so named because it turns up in all life, is on a roll for earning increasing respect.  At first discovery, scientists didn’t know what it did.  Then they learned it tags proteins for recycling by linking up into  small chains on cellular garbage.  Now, they are learning that there are various ways it forms chains on different attachment points, with different responses for each one.  Calling it a “potentially life-saving protein,” Science Daily describes the first hints that the structures of different poly-ubiquitin chains encode different signals to the cell.  For the latest variation described by scientists at the University of Maryland, its “function is something different and perhaps equally vital to maintaining healthy cells.”

Switching off inflammationScience Daily tells about an important molecule called DHA, found in fish oil, that is effective in switching off inflammation.  It appears to work by signalling white blood cells to produce another substance called maresin that acts as a molecular switch, turning the inflammation response off and the resolution process on.  “We encounter inflammation almost daily, but our body has ways of turning it off,” the journal editor commented.  “This is an important step toward understanding exactly this happens.”

Placental barrier:  How does the unborn baby keep from getting Mom’s cold?  Science Daily reports that “Placental cells may prevent viruses from passing from mother to baby.”  In the placenta, cells called trophoblasts seem particularly immune to viruses.  They work by secreting little packages of RNA, called exosomes, that can turn on programmed cell death to neighbors infected by viruses.  Researchers attributed this wonderful and necessary protection mechanism to evolution, stating that “the complex and elegant mechanisms human placental cells, called trophoblasts, have evolved to keep viruses from infecting cells,” and “this pathway could be a powerful evolutionary adaptation to protect the fetus and mother from viral invaders.”  It “could” be (7/01/13), but then again, it could not be.  The scientists gave no particulars about how an unguided, aimless material process “accomplishes this feat.”

Behind the placenta:  How does a developing embryo go from single cell to complex body, with organs like intestines made of tubes lined with epithelium that loop and curve in long passageways?  Some insights into this wonderful process were described in an open-access paper in PNAS, “Anisotropic growth shapes intestinal tissues during embryogenesis.”  It begins with an instability set up by patterning of cells having different structural properties:

Embryogenesis offers a real laboratory for pattern formation, buckling, and postbuckling induced by growth of soft tissues. Each part of our body is structured in multiple adjacent layers: the skin, the brain, and the interior of organs. Each layer has a complex biological composition presenting different elasticity. Generated during fetal life, these layers will experience growth and remodeling in the early postfertilization stages. Here, we focus on a herringbone pattern occurring in fetal intestinal tissues. Common to many mammalians, this instability is a precursor of the villi, finger-like projections into the lumen.

The herringbone (zig-zag) pattern appears to create a physical instability that induces buckling of the tissues, as different parts of the tissues possess different elastic properties.  “The growth anisotropy increasing with time, the competition between folds and zigzags, is proved to occur as a secondary instability,” they said.

How all these processes, and many others, come together in an adult human being who can read a book, play a piano or dive into a swimming pool after eating plants that captured sunlight must constitute grounds for sheer wonder and admiration in designs that transcend anything we know.

Three responses should be forthcoming at this point: (1) Appreciation for all we have been given in life.  How can we take for granted even the simplest pleasure or accomplishment, when we see the levels of organization that make it possible?  One begins to see the crime of failing to be thankful (Romans 1:21) for God’s magnificent designs in nature and in our own bodies in particular.  (2) Responsibility to care for what we have.  How would you treat a treasure, or an artistic masterpiece?  Would you hang an outstanding work of art on a chain-link fence in a junkyard?  Take care of what you have been given, flawed as it may be by millennia under the curse due to sin, and use it for good as much as you can.  (3)  Anger at the evillusionists who ascribe all this to chance.  “…elegant mechanisms… have evolved,” they say.  Ingrates.  No explanation, just BAD language (bald assertions of Darwinism), exhibiting willful ignorance masquerading as “science.”  If that is “science” (knowledge), then the Know-Nothing Darwin Party is behind the starting gate, facing the wrong way.

 

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