lotus

previous page: 17. Homeworld speculation - Speculations about the alien species (Movies: Alien)
  
page up: Alien Movies FAQ
  
next page: 17. This primitive life cycle might have proceeded as follows - Speculations about the alien species (Movies: Alien)

17. Hypothetical ancestors - 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. Hypothetical ancestors - Speculations about the alien species (Movies: Alien)

The presence of an endoskeleton and an exoskeleton implies that
conditions changed during the evolution of the organism, requiring
armored protection of the entire body. Drastically increased predation is
one such possible change, while a dramatic lowering of the pH of the
environment is a second. These options are not mutually exclusive; hostile
changes in the environment may cause increases in levels of predation.

A low pH ocean could literally dissolve its inhabitants, forcing
them to lower their pH to meet that of the environment, present a barrier
against the caustic properties of their surroundings, leave the oceans or try
these strategies in various combinations. Thick layers of continuously
renewed armor would be constantly ablated by the acid, but could protect
underlying tissues, and secretion of neutralizing substances could serve as
similar a shield. A lowering of the blood pH might offer some protection,
but might also begin to damage one's own tissues, and would probably be
energetically expensive. Raising the pH of one's tissues would not be a
successful strategy in an aquatic environment.

The aliens posses all of these characteristics to various degrees,
suggesting that the aquatic environment is either extremely caustic, or
became progressively more caustic in discrete degrees. The modern
species appears only to produce secretions in and around the mouth
region; possibly the protective substance has to be applied to exposed
regions of the anatomy, or whole body coverage is not necessary beyond
an aquatic environment. In the former case, hardening of the resin might
serve to bolster the exoskeleton, or the exoskeleton might be formed of the
same substance, secreted from the surface of the body. The endo- and
exoskeletons would be made from different substances in this case. In
either case, the secretions around the mouth are used for building the nest.
Ancestral types might have been covered in an additional layer of
secretions.

The larvae are known to have an external layer composed of some
combination of protein-polysaccharides and polarized silicon. Larvae do
not seem to produce secretions, and the external layer is not as hard in
appearance as the adult carapace. In non-nymph adults, this carapace has a
metallic appearance, and is probably composed of additional materials.
The teeth of nymphs often have a metallic appearance. If the hardening of
resinous secretions were the source of the exoskeleton, these secretions
might contain different substances depending on their intended use.
Secretions destined to become armor, structural material or strands and
cables might have very different compositions.

Living in a variety of challenging and dangerous environments
might favor the observed division of reproductive strategies. The organism
might be able to adapt rapidly to changing environments by using varying
morphologies and reproductive strategies as a means of "shifting gears".
An organism that was unconcerned with finding a mate could focus on
finding a carrier or host capable of moving its offspring to a potentially
more hospitable area. Organisms in a hospitable area could focus on
reproducing themselves as efficiently as possible. Primitive juveniles
could create embryos to be carried away by mobile hosts, while successful
adults could create multiple eggs which were suited to their environment.
Thus selection operates one way on the juveniles, selecting for those able
to find suitable hosts (including mobility when the environment is
shifting), and another way on the adults, selecting for those best suited to
their environment. This implies that primitive juvenile stages were capable
of predicting environmental shifts and altering their host selection
accordingly. That the modern species has an "atrophied" juvenile stage
implies that a stable environment was located, or that a novel strategy for
relocating was developed. The stable environment may have been space,
or perhaps there are yet unobserved castes capable of carrying eggs long
distances.

The ancestral organism's life cycle might have been similar to that
of a caterpillar/butterfly. The organism searches for a host off of which an
embryo may feed after being produced by a larva, much like a caterpillar
on a leaf. Possibly older pre-parasitic forms of this organism were like
caterpillars; the implanted "embryos" may have been mobile, representing
an intermediate life-stage (PRO-EMBRYO). It is possible that the nymph
stage may have occupied this position, having been produced from the
larva in a more advanced form. It certainly seems to be the case that the
juvenile and nymph stages of the modern species are developmentally
simplified. The modern larva is not capable of ingesting nutrients, being
solely devoted to implanting one embryo, and some modern nymphs
emerge sans limbs or with "limbs buds".

 

Continue to:













TOP
previous page: 17. Homeworld speculation - Speculations about the alien species (Movies: Alien)
  
page up: Alien Movies FAQ
  
next page: 17. This primitive life cycle might have proceeded as follows - Speculations about the alien species (Movies: Alien)