The creatures known as "gargoyles" and "gargoyle beasts" have been assigned the genus "Gargatus", with species names of "hominis" and "canis", respectively. The evolutionary origin of gargates is still unclear, as they possess characteristics that are unknown elsewhere in the animal kingdom. Among these are:
- their ability draw energy from both photosynthesis and substrate catabolism
- their strong stone-like outer skin and its rapid regeneration *
- their cosmetic variety and traits possessed by dozens of distant species
- the process that allows their eyes to phosphorize and "glow"
Over the millennia, the gargate has evolved so that its entire body is transformed into this hard stone-like substance during sleep. However, the effect is irreversible only in the outer epidermis, which is shed and regenerated with each cycle. There is slight regeneration in the subcutaneus layers as well, which may heal slight-to-moderate superficial wounds.
Many hypotheses have been made in an attempt to explain these unusual findings. To begin, let us go back to the common ancestor of the gargates, which we have named "Gargatus morpheus".
PHASE ONE: STONE-LIKE SKIN
The primitive gargate was forced to undergo rapid evolution as its environment suddenly shifted from aquatic to terrestrial. Although it was able to develop limbs for locomotion on land, the arms and legs were still connected by a membranous sheet which may have once served as its fins.
Studies indicate that the gargates first lived in a desert environment. To prevent dehydration and damage from the sun, they developed thick hides and melanin-related pigments. Their dermal tissues had the unique ability to bind and create various calcium and hydrocarbon compounds upon cell death, resulting in a hard stone-like outer skin. Underneath this layer were the pigmented cells, whose pattern of wavelength absorption gave the early gargates their characteristic granite-gray color. Thus, they had inadvertantly evolved a means of camouflaging themselves to aid in capturing prey or avoiding predators.
Much as the triceratops used their frills to dissipate excess body heat, the gargates retained their membrane fins for this purpose. This was especially important due to the fact that the gargates, unlike similar reptile species of the period, were warm blooded.
In order to maintain the illusion of stone, the gargate was forced to remain still for long periods of time in the dry, desert heat. It assumed a position with its head bent down and its limbs spread wide, stretching the membrane between them. This created a "tent-like" structure, where the underbelly was now shielded from the sun and winds. It was imperative to protect this region from dehydration, for the underbelly also contained the large pores that the gargate used for excretion. One of the compounds believed to be excreted was a pheromone found to attract certain species of small animals.
The hard outer skin of the gargate was useful in protecting it from its harsh environment, but it also made movement slow and difficult. Thus, the gargate could not chase down its prey, and had to wait patiently for a creature to settle in its shade before closing in for the kill. This worked well for a time, until their their prey had become either scarce or had learned to avoid their traps. However, as the laws of natural selection state, "when the prey evolves, so too does the predator".
PHASE TWO: PHOTOSYNTESIS
Some primitive unicellular organisms can use their pigments to capture the energy of sunlight and transform it into fuel. As plants evolved, these organisms were somehow incorporated into them (chloroplasts), allowing plants to also undergo photosynthesis. Animals lack chloroplasts, and so their pigments only serve to absorb dangerous wavelengths of ultraviolet light. The gargate however, seems to have either acquired its own set of chloroplasts or has modified its pigments and cellular machinery to allow for photosynthesis. Either way, this adaptation drastically changed the gargate's lifestyle.
The pigments lying in the gargoyle's endodermal layer are thought to absorb a wide spectrum of light encompassing both violet and ultraviolet wavelenghts. This would provide almost three times the energy of red light, the form most strongly absorbed by chlorophyl. In addition, gargates possess an underlying layer of cells containing a secondary pigment, the identity of which may vary over a wide range between individuals.
Light must first pierce several layers of the gargate's hard outer skin before reaching the light-absorbing cells underneath. For this reason, as the dermal cells die and are pushed out towards the surface, they lose their pigments and become transparent. Although the outer skin appears to be the color of stone, it is actually the reflective properties of the deeper epidermal layers that give it that appearance.
As the products of one are the required substrates of the other (i.e. oxygen and carbon dioxide), at first it was believed that the processes of photosynthesis and substrate catabolism in the gargate would be able to feed each other in a continuous cycle and make breathing obsolete during the day. This is true to some extent, however the gargate's metabolism is significantly slower when it is asleep, and insufficient levels of carbon dioxide are produced (and insufficient levels of oxygen withdrawn) to run photosynthesis. Therefore, the large pores along the gargate's underbelly, which had originally served to excrete pheromones and sweat, were now recruited for a very stoma-like function. The ventral pores led to a capillary bed where the gases were exchanged and carried through the bloodstream to the photosynthesizing cells. At night, the primary site of gas exchange was the lungs, although the pores could still contribute to a small degree. The contribution from the pores became significant, however, during periods of high exertion.
Having the ability to absorb energy from the sun, the gargates no longer relied so heavily on capturing their food. However, the gargates still required a source of protein, as they could not fix atmospheric nitrogen. Having evolved as carnivores, they preferred eating meat over over plants, which they rarely touched. The meat also served as an extra source of energy, as photosynthesis was obviously resticted to daylight hours. As a result of these changes, the gargates abandonned their camoflauged traps and became nocturnal hunters. Because the hard outer skin restricted their movement and made it difficult to chase down prey, the gargates developed the ability to shed their skin at night. This exposed the deep pigmented layer, which is responsible for the various colors associated with the gargate species. Because the underbelly contained such a large number of pores instead of pigmented cells, the color tended to be lighter in that region.
Hunting is thought to have been most effective directly after sunset, when decreased input from the photoreceptive cells triggered the shedding of the outer skin. As the night progressed, the photosynthesizing cells would slowly be replaced, pushing the old cells outward to become the new protective layer. This caused the skin to lose its color and the gargate's movements to become more sluggish as sunrise approached. Although they no longer needed to spend the day standing motionless in order to trap prey, the gargates found that they absorbed sunlight better if they remained still. As they were now nocturnal, they also took advantage of this time to sleep and recuperate. The hard stone-like skin proved to be useful in keeping the gargate hidden from predators while they were thus exposed, as well as protect them from superficial wounds.
PHASE THREE: MUTATION
At some point in time, the gargate evolved to form the two species seen today--gargoyles and gargoyle beasts. A major event that may have initiated this change would have been the recession of the membrane fins in the case of G. canis and the development of a wing structure in G. hominis. Although the gargoyle was too heavy to produce the necessary lift for flight, the wings could still hold the body suspended over strong currents of air. In order to help coordinate this manner of "gliding", the wings required a third set of a limbs, which may have originally run along the membrane between the arms and legs. Over the millenia, the new limbs shifted farther back and towards the shoulder, taking the wings along with them. This change in wing-style may have developed in order to compensate for the increasing size of the gargoyle species, as their weight would be more easily supported by a larger wingspan. Smaller gargoyles can still be seen today, however, who carry the original wing pattern between their limbs.
One would assume that these remarkable evolutionary feats were the extent of the gargate's legacy. However, one mystery still remains which has frustrated scientists and taxonomists to no end. How does one explain the wide variety of characteristics exhibited by both gargoyles and gargoyle beasts alike? The differences in facial morphology and wing structure are only two of the most commonly cited examples.
A new theory has recently been proposed that could at last shed light on the problem. Scientists believe that during the rapid evolutionary period preceding the branching of the two gargoyle species, a virus that preferentially infected gargates was induced to undergo mutation and evolve as well. These changes allowed the virus to invade a wider range of hosts. However, its ability to selectively package viral DNA was compromised, and as a result, host DNA was often incorporated into the capsids along with the virus. This had little effect on the new hosts or the virus, but had interesting consequences in the gargate.
Because gargates absorb potentially damaging high-energy radiation, they have developed a system of DNA repair that relies principally on homolgous recombination. For example, if two thymine bases became linked through the effect of ultraviolet radiation (forming pyrimidine dimers), this could result in a potential misread by a newly synthesized DNA strand that relied on the altered strand as a template. Thus, the mutation is propagated and tumorgenesis may occur. The gargate, however, possesses special enzymes that detect the mutated DNA bases and replace them with the corresponding fragments from a non-altered strand.
When the above-mentioned virus carries DNA from other species and infects a host, all of the DNA is injected into the host cell and replicated. Only in the gargate, however, can this foreign DNA be mistakenly used to replace host genes. Thankfully, the gargate's evolutionary changes protected its somatic cells from invasion by the virus. However, its germ cells (eggs and sperm) were still vulnerable, and became the main target for infection.
It is believed that the vast genetic variability seen among both gargate species can be attributed to these enzymes and the altered virus. It is amazing that the newborn gargoyles were able to survive with their genomes thus altered, however, the principle behind homologous recombination makes this less improbable than it might otherwise seem. In order for the enzymes to consider a foreign gene as a candidate for replacement, it must possess a high degree of similarity with the host gene. This implies that the foreign DNA will encode one or more genes related to those of the host, but potentially very different (for example, encoding hooves instead of toes). Scientists argue that for this to account for the extent of the variability observed in gargates, multiple genes would have to be affected in a single individual. This may in fact be the case, if one considers the fact that an infection would involve multiple virus particles, each potentially carrying a different set of genes from one or even several other species.
It has been observed that the gargoyles can carry traits resembling both prehistoric creatures and modern day animals, including man. The proposed explanation is that the virus died out at the same time as the dinosaurs, then resurfaced some time within the last million years. There is no sign of the virus at present, although it may simply be lying dormant, ready to resurface at any moment.
Whether or not the viruses can be considered symbiotes is still in question. Certainly, there may have been some selective advantage to the traits it bestowed. The gargoyles' ability to stand erect and speak may have evolved from human DNA. It is interesting to note that these are some of the few traits that are preserved in all gargoyles. Longer tails may then have been favorably selected for in order to properly balance their weight when standing upright. In addition, many gargoyles developed fingers or spikes on their wing limbs, perhaps as a result of the virus or homologous recombination within the gargoyle's own DNA (between wing limbs and hands, for instance). The latter is also an important process during development, as DNA from either parent may not be compatible, and the embryo must choose between one or the other. For example, in regards to beaks or flat-faces, the morphological differences are so extreme that an intermediate form would not be possible. Unlike height, which is determined by the cumulative effect of genes inherited from both parents, different sized beaks would each be encoded by a separate single gene. If this were not the case, most gargoyles would possess intermediate-sized beaks, with small number of gargoyles at either extreme. Flat faces, however, are the observed norm, perhaps because the allele is more commonly represented within the gargoyle population. In the case where a child is born to both a long-beaked and flat-faced parent, homologous recombination would occur between the alleles of either parent, until both of the child's gene copies contained the same allele.
Together, these extensive genetic changes are believed to be the cause of the unusually long gestation period of gargoyle eggs (approximately ten years). If the embryo encounters problems during development, it has the limited ability to "go back and start over". The fetus can therefore change its form several times, altering its looks until it finds one that suits it best. Thus, it is very rare for a gargoyle to hatch with any deformity. This is especially important considering the limited number of eggs that females can lay during their lifetimes. In addition, gargoyles undergo a process prior to hatching which destroys any surplus DNA from either the virus or the parents, preventing further genetic mutations.
There are several other observations about gargoyles which should be included in this report.
- WHY DO THEIR EYES GLOW? Gargate eyes are unusual for several reasons. When they were first evolving in the desert, they needed to be able to see in very bright light. Their irises were therefore very large, and contained a special white pigment that reflected the light and reduced the levels in the eye. These pigments can photosynthesize to a limited extent, and the light thus absorbed can be re-emitted voluntarily by the gargate. The photosynthesizing cells in the skin can also sometimes give off this glow when the outer shell is being shed. Female gargoyles produce an additional pigment that gives their eyes a reddish glow.
All gargates have pupils, but they are very small and even appear absent in gargoyle beasts. This is contrary to what is expected of a nocturnal species, however it is believed that the same white pigments that reflects light outward during the day is able to absorb and reflect light inward towards the retina, amplifying the signal at night.
- WHY ARE A GARGOYLE'S WINGS A DIFFERENT COLOR? DO THEY HAVE PORES THERE TOO? Actually, gargoyle beasts are the only ones who still carry a significant number of pores on their ventral surface. When gargoyles began to walk upright, their bellies no longer offered sufficient protection against dehydration, a major concern for their open pores. The pores eventually recovered their old secretory functions and developed an oily substance that could spread over the opening to form a water-impermeable membrane, eliminating at last the problem of dehydration. Now the pores' secondary function as sites of gas exchange during exertion became critical in deciding where the pores would lie. Because exchange is most efficient when the air around the pores is rapidly renewed, surfaces most exposed to currents of air--such as gargoyle wings or the long protruding ears or manes of gargoyle beasts--tend to be sites where these pores are concentrated. The amount and chemical composition of the oily substance that the pores secrete may differ between certain gargoyles. In some cases, it even affects the color of the skin.
- WHY HAVE THEY EVOLVED SO THAT THEIR ENTIRE BODIES TURN TO STONE? This is a difficult question to answer. In fact, it is not known how the cells can survive if they are turned to stone (remember that the hard stone-like outer layer of skin is composed of already dead cells). Unlike the dead outer layer, the cells in the rest of the body are not shed, but rather revert to a normal flesh-like state (this regenerative process is also capable of healing minor wounds). Because no scientific explanation can be given for this phenomenon, one must assume that the cause involves magic. It has already been revealed that the gargoyles' clothes and personal items have the ability to turn to stone with them due to the effects of an ancient spell. It is possible that this spell was powerful enough to cause the gargates' entire bodies to turn to stone during the day. Although this condition would normally lead to death, magic is known to break the laws of nature. In addition, by turning their entire bodies to stone and being cued to the rising and setting of the sun, the spell effectively prevents gargates from ever being awake during the day.
- Both humanoid gargoyles and gargoyle beasts were depicted in the 1990s animated series Gargoyles.