April 3, 2015 | David F. Coppedge

Your Body: Design from Head to Toe

Every body part has its place and is well-designed for its function.

This is just a quick list of new findings about the body, with links for further study.

Your interface to the world: PNAS says, “The human skin is an organ with a surface area of 1.5–2 m2 that provides our interface with the environment. The molecular composition of this organ is derived from host cells, microbiota, and external molecules.”

Rip resistance: Your skin is remarkably resistant to tearing, Science Daily says. A photo shows why: “Collagen fibrils in the dermis of the skin are normally curvy and highly disordered, but (right) in response to a tear align themselves with the tension axis (arrow) to resist further damage.”

Wound healing: Science Daily says that the mystery of wound healing is being unlocked by research at the University of Arizona. How do cells rush to heal a wound? To start with, there are leader cells and follower cells.

Wong’s team observed that when cells collectively migrate toward a wound, leader cells expressing a form of messenger RNA, or mRNA, genetic code specific to the DII4 protein emerge at the front of the pack, or migrating tip. The leader cells, in turn, send signals to follower cells, which do not express the genetic messenger. This elaborate autoregulatory system remains activated until new tissue has covered a wound.

How a wound closes: In addition, cells move cooperatively to form new ranks, says Science Daily about research at the University of Heidelberg. The article tells how a protein named Merlin runs a “marathon” as it senses tension and sends signals to other proteins. Merlin is also a tumor suppressor.

Echo chamber: To identify the location of a sound, we need to hear echos, Science Daily says. The bouncing echoes in the environment, heard from two points of view in the two ears, provide our brains with localization cues. Reverb is part of our auditory sensing.

Breast milk: The “digestive brilliance” of mother’s milk is explored in an article on PhysOrg. The milk forms into highly-organized structures during digestion that are key to the infant’s nutrition. “Human breast milk is key to the survival and development of humans, yet until now we had no idea of the rich structure formation when it is digested,” a researcher at Monash University said.

Bionic leg improves on evolution?  Nature says that an unpowered”exoskeleton” that looks like a calf brace can improve energy efficiency while walking. The headline says that this “improves on evolution” compared to the natural leg, because people walking with the brace use 7% less energy. “That may not sound like much, but the mechanics of the human body have been shaped by millions of years of evolution, and some experts had doubted that there was room for further improvement in human locomotion, short of skating along on wheels.” The invention would surely be a hindrance for swimming, gymnastics, and dozens of other human activities, though.

Live and let liver: The liver has a backup system to recover from crisis, Science Daily reports. It comes in the form of an “antioxidant system” that relies on methionine, one of the amino acids found in dietary protein. Mouse livers that were under stress and threat of failure revived with methionine in the diet when the two other antioxidant systems in liver cells, the thioredoxin and glutathione systems, were not working.

Eye of the cyclops: We have two eyes, but get one image. How are they merged into a singular view of the world? The brain works as a cyclops, Medical Xpress says, compensating for the differences in the images. Visual calibration performed by the brain gives us a sharper image than a single eye could.

Did language evolve?  Humans are verbal communicators. Put any two together, and a conversation is likely to develop, using abstract concepts, reasoning, and basic assumptions about morality. This is made possible by unique vocal apparatus and a brain able to command it for a purpose. Did all of this come about by slow and gradual accidental mutations? Consider this statement in Science Daily by a linguist from MIT: “The hierarchical complexity found in present-day language is likely to have been present in human language since its emergence.” It should be noted that selection acts only a single traits, not hierarchical complexity.

Are you thankful for these insights coming from design-based science?  It’s design-based, because there is a subtext that assumes purposes exist for things we do not yet understand. The few mentions of evolution are throwaway lines. When we see design, our response should be thankfulness, and a redoubling of efforts to increase our understanding with deeper research.

 

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