January 14, 2015 | David F. Coppedge

Animals Come Pre-Equipped With Machinery

Guidance systems, compasses, switchboards, motors, robotic machines: we’re talking about systems inside animals—and you.

Internal compass and route finder:  Many animals travel long distances.  It’s been known that animals as diverse as birds, turtles and fish are able to form mental maps of their routes using environmental cues like smells, light and the earth’s magnetic field.  Mammals, in particular, have a portion of their brains devoted to route memorization, so that they can find their way back: it’s in the entorhinal complex of the hippocampus.  There are specialized neurons called grid cells and place cells, Medical Xpress explains, that respond to movement and even the directions the head turns.

Amazing FactsThese grid cells fire in a tessellating pattern when an animal travels and seem to operate a bit like graph paper, providing an animal with a sense of the distance travelled. Information about direction is stored in head direction cells, which fire when an animal is facing a particular direction (north, for example).

All these pieces of information are fed into the place cells, which bring it all together – hence why we really can consider the hippocampus to contain our own internal, spatial map. This was so significant to our understanding of how the brain operates that the 2014 Nobel Prize in Physiology was awarded to John O’Keefe, who was the first to identify place cells, and Edvard and May-Britt Moser, who discovered grid cells.

New work published in Current Biology adds to this knowledge by locating the compass.  A map is not good enough alone; one needs to have a compass to be able to use it. “The paper’s authors have established where this information is stored in the brain, and how it might be used to orient a human or animal.”  Using fMRI on human subjects put into virtual environments, the researchers found that the compass can work even when the person has his or her eyes closed:

Interestingly, the pattern of neuronal firing is remarkably similar when someone is facing in the goal direction to when they simply imagine the direction of the goal. The researchers suggest that the brain can use this property of the neurones to simulate the intended direction in the brain without actually moving. They assume that head direction cells switch from one role to another, so that they are initially involved in representing the current heading direction, before switching to simulating the goal direction. In this way, the neurones can aid in planning the route home.

Some people are better at navigating with their “internal compass” but apparently the skill can be improved with practice.  Many mammals rely heavily on this ability; maybe it explains the old song, “The Cat Came Back.”

Switchboard circuitry:  A library needs to control the flow of information.  Having all the instructions to build something can be “TMI” (too much information) without being able to access it in the right order at the right time.  DNA is like that; what gene should be translated, and when?  Those decisions are regulated epigenetically (“above the genes”) by a large squad of little machines called acetyltransferases that put tags on genes, controlling which ones need to be translated and which should be sealed off.  Higher mammals have up to 60 of these taggers, and fruit flies have 40, all employees of a company of switchboard operators in the nucleus of the cell.  This amazing “epigenetic switchboard” is described in a press release from Ludwig Maximilian University in Munich, Germany.  The system, conserved throughout the animal kingdom, is as elegant in fruit flies as it is in humans.  It’s very robust, too:

“Our most surprising finding was that the depletion of single acetyltransferases often leads to the attachment of novel acetylation tags at nearby sites, so that the overall level of acetylation is often very similar to the normal one,” says Feller. The ability of biological systems to compensate, at least in the short term, for the loss of individual functional components is well known. “However, the degree to which the histone acetylation system is able to accomplish this feat was a big surprise,” Becker adds, “and it illustrates the complexity of the circuitry that links the various epigenetic signaling pathways.”

Motorcycles:  There’s an elaborate transportation network inside cells.  So small we can’t even see them, cells are actually filled with mechanized transporters going to and fro.  If you imagined yourself shrunk down to the size of one of these transporters, you would behold a vast network of highways called microtubules all around you, crowded with walking machines carrying cargo.  One of the motorized transporters, called dynein, is described in more detail on PhysOrg alongside a model of how it looks.  Using an ATP molecule for energy at each step, dynein transfers this energy some distance down a stalk to the moving foot.  Biochemists at RIKEN, who had no hesitation calling this a “molecular machine” or “motor,” learned that the structure of the stalk at the microtubule interface harnesses the energy to give it directionality, which would otherwise wobble randomly under Brownian motion.  When these transport machines don’t work, serious health problems can result.

An animal is not going to be able to reproduce without all this machinery in place, doing its job.  If it can’t reproduce, it has no evolutionary fitness.  Yet each of the systems described above is composed of multiple parts required for function.  If a Darwinian believes that machine parts can emerge by chance, that doesn’t help; like Ann Gauger says in Flight: The Genius of Birds, we know that you can’t get a 747 by throwing all the parts on a floor and blowing them around with a fan, “even if you have all the parts.”  It’s not just the parts that makes an animal work, but the way they are organized into machines and systems of machines at several hierarchical levels of control.

This satisfies Darwin’s own falsification criterion, where he said, “If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.”  In 1859 he might have been able to say “I can find out no such case,” but not now.  Darwin knew nothing of biological machines, and neuroscience was virtually unknown to him.  So was genetics and epigenetics.  Darwinian evolution is thus falsified; it has absolutely broken down.

Now that we know that, why don’t we ditch all the old Darwinian baggage out of our minds, and look at the world afresh?  It’s a designed world, a designed planet, and a designed universe.  We are a Privileged Species.  Click that link and enjoy the movie, narrated by a molecular biologist whose 1986 book energized the intelligent design community, Dr. Michael Denton.

 

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