17. Discussion of observed characteristics - Speculations about the alien species (Movies: Alien)
Description
This article is from the Alien Movies FAQ, by Darryll Hobsonand Eelko de Vos E.W.C.deVos@TWI.TUDelft.NL with numerous contributions by others.
17. Discussion of observed characteristics - Speculations about the alien species (Movies: Alien)
The alien life cycle is divided into two distinct stages which are
reminiscent of the alternating sporophyte and gametophyte generational
stages of plants and fungi. Plants produce distinct types of reproductive
cells (spores or gametes) which give rise to genetically distinct types of
organisms. Spores grow into gametophytes, which produce gametes, while
gametes fuse to form sporophytes which produce spores. In the alien
species, the sporophyte stage could be represented by the juvenile stages.
These would create the embryo. The gametophyte stage could be
represented by the adult stages. These would create eggs after gamete
fusion. Such a strategy in might be indicative of an chaotic and dangerous
natural environment (see discussion of hypothetical ancestors). We have
zero knowledge of the genetics of these creatures, and further speculation
on the existence or nature of alien reproductive cells would be unfounded.
The alien morphology seems to be a melange of arthropod and
vertebrate characteristics. The segmented exoskeletal carapace and
variable numbers of limbs are reminiscent of terrestrial arthropods (as well
as armored fishes and reptiles to a lesser extent), while the adult body plan
seems more vertebrate in nature; the presence of a jaw, spine terminating
in a tail and limbs ending in grasping hands and feet as opposed to the
mouthparts, legs and body plan of an arthropod suggest a vertebrate
morphology. The larval legs are articulated via an endoskeleton, which
appears to be covered in a sheath of muscle and a pliable external layer of
protein and silicon. This seems to indicate that the oldest ancestors of
these creatures possessed endoskeletons, and that exoskeletons evolved
later. As is the case with vertebrate evolution in the Silurian and Devonian
periods, the endoskeleton may have evolved first as a means to protect the
CNS, and the exoskeleton could have evolved secondarily; in response to
environmental challenges.
The eggs are complex organisms in and of themselves. They are
responsible for maintaining life support for the larva for an indefinite
amount of time, and must recognize a potential host and distinguish it
from valid members of the nest. The eggs contain rudimentary moving
parts. Once the egg has determined that a host is proximal, it releases the
larva. In the modern species, the egg is flammable, translucent and
unarmored. Their gracile nature in comparison to the adults may be in
response to the security afforded by the nest strategy. Because of these
unusual qualities in an egg, it might be that the egg and larva constitute a
single organism up until the point where the larva is released. The size of
an egg in comparison to the size of the contained larva indicates
substantial internal morphology, consistent with requirements for life
support and sensory systems.
Despite the obvious immediate differences, the organism's basic body plan
may be conserved between the juvenile and adult forms. The larval form
has 8 legs, and while imago forms only appear to have 4 limbs, queens
appear to have 8. All forms have a single articulated tail, implying the
presence of a spine and CNS. As the juveniles posses an endoskeleton it
could be assumed that the adults do as well. The adult head morphology is
quite distinctive. In the post-nymph forms, the mouth contains a secondary
set of jaws on the end of the tongue, and the head is long and curved. In
the modern species, it is probable that the larval form is derived to the
point where a majority of the sensory portions of the larval body remain in
the egg when the larva is released. Anatomy corresponding to the adult
head may be contained within the egg. Accordingly, if the juvenile "air-
sacs" are used for respiration, any adult breathing apparatus would be
located posterior to the hindmost pair of adult legs. Four "vanes" are
visible on the backs of most adults, and six are visible along the backs of
queens. These may function in breathing. Additionally, the head
configuration of the adult may be adaptive in that it would prevent
accidental implantation of an embryo into an adult by a larva, or prevent
intentional implantation by a larva of another species. The legs of the larva
will not easily grasp the adult head, and the ventral "embryopositor" tube
will be subject to attack by the mouthed tongue. This may suggest that
there are competing species of these creatures on the homeworld.
While in the egg, the larva remains suspended in a fluid, suggesting
aquatic origins for this species. The emerging larva retains a thin coating
of the internal fluid, and this layer appears to be caustic, although the
caustic properties are not as dramatic as those displayed by the organism's
blood. The combination of the egg fluid and blood pH indicates drastically
different aquatic environment on the homeworld than on earth. It is
possible that the pH of the egg fluid is closer to the true pH of the oceans
on the homeworld and that the caustic properties of the organism's blood
are due to a combination of modification and adaptation to the parasitic
lifestyle, or the egg maturation process may deplete the egg fluid of its
caustic properties.
It is likely that the caustic properties of the blood are not due to
simple pH, but that other chemical and enzymatic factors are in
effect. In addition to functioning as the medium for an internal
transport system, the organism's "blood" might be its digestive
system, which would suggest an extremely different internal structure
than terrestrial standards. The caustic properties of the blood appear
to be more effective on synthetic and organic materials than on
metals, supporting the idea that other chemical and enzymatic factors
are at work, which in turn supports the digestive theory.
Interior carapace pressure might indicate a higher average planetary
pressure than 14 psi. This could be a defense mechanism, or it could
simply be circulatory pressure. The internal physiology of the
organism has yet to be revealed to any great extent, but pulsing
"artery-like" structures have been observed in emergent nymphs,
implying some sort of pumping "heart" organ. Possibly the homeworld is
larger or the atmosphere is heavier than on earth. The larval air
sacs/bellows might be a historical adaptation to living beyond the
aqueous environment, but it is possible that these are a parasitic
adaptation, and are not required by the organism. The degree to which
they function is probably dictated by the atmospheric requirements of
the host, but we have no knowledge of the organism's atmospheric
requirements. If such sacs are required, the larva will not survive in
vacuum. The adults appear to function as well underwater as out of it,
implying that the do not use air sacs. It is possible that inert
gasses irritate the adults. Possibly, they breathe using modified gill
structures located in the dorsal vanes.
Body temperature is ambient, perhaps indicating a generally warm
planetary surface temperature, or geothermal habitat requirement. It
remains to be seen how long the imago can survive in a vacuum or sub-
freezing temperatures. The low pH of the blood would seem to indicate
a drastically reduced freezing point. Queens survive extended periods
of transit through both of these environments, and it is possible that
other instar and imago forms may as well. The various adult forms
demonstrate aversion to open flames, but unlike the eggs and nymphs,
are not flammable. This suggests temperature boundaries within the
upper limits of terrestrial environments.
The lack of obvious eyes in any observed stages indicates that the
aliens either live entirely in enclosed or subterranean areas, or that
there is no visible light incident on the surface of the homeworld. If
the organisms lived entirely underground, their size and potential for
well populated nests implies a well developed and robust subterranean
ecosystem. If they lived the entirety of their lives in their nests,
they would be dependent upon the movement of prey and hosts into the
nest for survival. It is possible that they lure these into the nest,
but the aliens seem quite capable and adept at retrieving them as
well. If they dwelled on an illuminated surface for any amount of
time, eyes would be a distinct advantage.
The aliens display significant ability to cling to and move on
vertical and inverted surfaces, supporting the idea that a significant
portion of time is spent underground or in enclosed spaces. Nests fit
this description, and it may be that castes which venture outside of
the nest posses eyes. In this case, these castes have not yet been
observed. The nests might be constructed above or below ground or
water, but seem to be designed so that the resinous construction
material covers all surfaces near their cores. Partially submerged
nests would require air chambers for hosts and larvae.
Copious amounts of a viscous substance are constantly being secreted
from the mouthparts and neighboring regions. This substance appears to
be used in constructing nests, hardening to form a resin. Thick
strands may also be produced, although the mechanism for this is
unclear. Prior to hardening, the resin does not display caustic
properties, and may act to neutralize acids. This would be useful,
both in offering protection from an acidic environment, and in
protecting the nest from being accidentally dissolved.
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