This space race ....

[Ava]

How could they survive in the same form for such a long time (thousand years?) when actually they are changing their genetic code with every new host?
Wouldn't they be changing from generation to generation to a different species? Just wonder 

[maledoro]

The only source of alien eggs (that we know of) came from the derelict, and they were (most likely) in stasis (in the blue mist). Thus, their being around for thousands of years.

The alien that emerged from Kane came from an egg that was a transformed Jockey. (Remember the original alien method of reproduction where the aliens would transform some of their victims.) Some of the Jockey's biomechanoid traits were part of the Nostromo alien. Ridley Scott mentions this in an interview:

The alien life form lived to reproduce, and in reproducing took on the characteristics of the space jockey on the derelict and Kane. If the facehugger had hit the cat, it would have been a hybrid of the space jockey and the cat.

Fantastic Films; November, 1979

[Ava]

Yeah, I understand. But I still don't understand how a species can survive for thousands of years with only limited changed in it's biology, when it's changing it's DNA with every new generation.
Nostromo alien was a hybrid of jockey and Kane. IT's descendant would be jockey/Kane and , I don't know, a cat? And so on and on...there would be THOUSANDS of species out there, originated from the first Queen. After years, what would be left from the real alien DNA?

[maledoro]

Yeah, I understand. But I still don't understand how a species can survive for thousands of years with only limited changed in it's biology, when it's changing it's DNA with every new generation. Nostromo alien was a hybrid of jockey and Kane. IT's descendant would be jockey/Kane and , I don't know, a cat? And so on and on...there would be THOUSANDS of species out there, originated from the first Queen. After years, what would be left from the real alien DNA?

For thousands of years, one generation has been dormant. As for the "limited change", we don't know how many mutations and variations have taken place since their genesis. All we know of the Nostromo alien is that it has traits from a Jockey and Kane. But, strip those traits away and we don't know how much of the alien is "pure" and how much of it came from one or many other species before the Jockey's DNA got mixed in.

The only way we could know for sure is to get an original or if we could learn about the other animals that the alien's traits had adapted to. If we had a fossil record of the creatures of the alien's homeworld, we'd be able to decipher the DNA to find its original pattern.

[deezelboy]

How could they survive in the same form for such a long time (thousand years?) when actually they are changing their genetic code with every new host?

Becuase they don't meet that many hosts in a thousand years or so.  Kane and Mr Jorden has supplied the entire progeny of ALiens we see in the Alien films.  AVP has its own agenda (and tragically there's nothing to say the AVP Queen didn't come from that Derelict either).

[beckmen]

Basically, I think there's two schools of thought on this one...

1: The xenomorphs as we see in the movies are in their more of less 'pure' form. No matter what hosts they take, they'd still look more or less the same. They only absorb a small amount of DNA from their hosts, so over generations they'd still look like the human/dog creatures we see in the first four films, with only a few small modifications such as how they move and slight changes in behavior.

2: The xenomorphs have no genetic purity. They absorb DNA from their hosts and adapt as needed. Therefore after generations as they adapt...they would cease to even resemble the creatures we saw in the first four films. They'd start evolving into other things like the Predalien or even the Newborn, and beyond. Their reproduction methods might even change. An ever-evolving species, that evolves as a pace quicker than any terrestrial being...therefore, they adapt so quickly that they are the most resilient life-form in the universe.

Or it could be somewhere in the middle. Me, being a big Aliens fan...personally like the first option. It's just what I grew up on. But the second option is actually more interesting. So I am kind of torn on this issue.

[Ava]

Intersting...thanks guys!
Now I would love to see the original, pure Alien. 

[Thedus]

Which raises the question: was there ever one?

If the Alien was bio-engineered it would have been designed with gaps in its DNA so that it could take on gross anatomical traits of its host.  Those gaps would have most likely been filled with either the DNA of the engineering species, or some "complimenting" species (i.e. - one that aided the over all concept and design of the alien).  And then from there those gaps in the Alien genome would be filled again by the next species that was infected, and so on. Meaning there would be no such thing as a "pure" alien.

And if the Alien evolved it would have evolved to rely in a host to complete it's genetic structure, so essentially it would have always been like that.  The species it evolved from may not have required host DNA to develop, and as a result its genome would differ from the alien's, thereby making it a different species.

I agree with Beckmen's first theory, but not he second.  As he said the alien always appears inherently "alien" (for lack of a better word).  This would seem to indicate that the alien has a very specific portion(s) of its genetic code that is left open and relies on a host's DNA to complete those gaps. So each generation of facehugger would carry with it the alien genome with the same gaps as the previous generation. These gaps are continuously filled with each infection, but because of the alien's genetic make-up the gaps always occur in the same places with each generation so you don't get "cross breeding" such as an Alien+Gog+human+Predator.  You would always get Alien+whatever.

The existence of the Newborn is a result of human interference and tampering with the alien's basic genetic structure.  I doubt the Newborn, or anything like  it, would have existed had it not been for Wren screwing around with DNA to try and clone Ripley.

[beckmen]

Keep in mind that a possible reason that the human and dog aliens looked so alike could be because the DNA is actually quite close in the first place. But I do admit that I am pretty clueless as to how DNA works. These gaps you speak of...I am not sure if they'd be necessary, or if the organism could simply evolve, discarding some DNA in favor of other DNA that it's recently absorbed from it's latest host.

[Ava]

Now we need an advice of genetic engineer...do we have some?! 

[fitzley]

Wames2 used to be good for such knowledge, but he comes and goes with months in between his appearances.

[Thedus]

That was the first name to come to mind for me as well.  He's been an immense help with my site when it comes to bouncing ideas off of some one, and helping in fleshing out ideas concerning genetics and chemistry. 

[fitzley]

Send him a message and tell him we need his immense knowledge to explain the predalien to us!

[Nightmare--The Skull Collector]

i got a theory

alien DNA is incomplete by nature, the host completes it, this way the alien DNA is always there pure,

so, the basic and most important DNA is imutable


if queen takes host DNA and transmits it to facehugher, the new host will replace old host DNA (at least partially)

so, even if queens take host DNA alien come out "pure" (even if the facehughers carry some queens host dna),

i like this theory, cause it explains every diferent alien design (just previsous queen host partial DNA cause the minor diferences)

EDIT:

i havent read the wheol thread, jsu t1st psot....

looks like someone alredy sayd something similiar to what i posted...

[Thedus]

Send him a message and tell him we need his immense knowledge to explain the predalien to us!

I'm on it.

EDIT: 11.05.07 - Wames wrote back.  He's uber busy, but he'll swing by when he gets a chance.